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  • 1970-1974  (684)
  • 1890-1899
  • Electron microscopy  (425)
  • Rat  (288)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 281 (1974), S. 175-196 
    ISSN: 1432-1912
    Keywords: Intestinal Absorption ; Basic Drugs ; Amidopyrine ; Antipyrine ; Solvent Drag ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Jejunal loops of anaesthetized rats were perfused with hypotonic, isotonic and hypertonic buffered solutions containing 14C-labelled amidopyrine and antipyrine at neutral and at acidic pH. The blood flow of the loop was maintained at an intermediate rate (0.7–1.0 ml min−1g−1). The water net flux was determined by means of polyethylene glycol as non-absorbable marker and amounted up to ±30 μl min−1g−1. 2. A positive water net flux (directed towards the blood) increased the appearance rate of amidopyrine and antipyrine by maximally 43.8 and 49.2%, a negative water net flux (directed towards the gut lumen) diminished it by 38.8 and 35.0%. 3. The experimental data were analysed by means of a kinetic model with the water net flux as independent variable and the epithelial permeability kF D , the serosal permeability k S F S and the sieving coefficient Φ=1−σ as absorption parameters. For antipyrine independent of the pH-value of the perfusion solution kF D was 0.123, and, for amidopyrine at pH 7 and pH 3 kF D was 0.231 and 0.091, respectively. k S F S was zero indicating that in this experimental arrangement the transfer of drug molecules to the serosal side was negligible. The sieving coefficient Φ amounted to 2.30 for amidopyrine and 2.15 for antipyrine at neutral pH. At acidic pH it amounted to 0.50 for amidopyrine and 1.44 for antipyrine. The hydraulic permeability of water was identical at neutral and acidic pH. 4. The high sieving coefficient for the two drugs at neutral pH is interpreted as indicating that water and lipophilic drug molecules interact within the lipid part of the cell membrane. At acidic pH the ionized drug molecules appear to permeate the cell membrane preferentially across other (presumably more hydrophilic) areas.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 281 (1974), S. 197-217 
    ISSN: 1432-1912
    Keywords: Intestinal Absorption ; Acidic Drugs ; Benzoic Acid ; Salicylic Acid ; Solvent Drag ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Jejunal loops of anaesthetized rats were perfused with hypotonic, isotonic and hypertonic buffered solutions containing 14C-labelled benzoic acid and salicylic acid at pH 6.2 and 2.2. The blood flow of the loop was maintained at an intermediate rate (0.78–0.97 ml min−1 g−1). The water net flux was determined by polyethylene glycol as non-absorbable marker and amounted up to +31 or-27 μl min−1 g−1. 2. A positive water net flux (leaving the gut lumen) increased the appearance rate of benzoic acid and salicylic acid in the intestinal venous blood by maximally 47 and 41%, a negative water net flux (entering the gut lumen) diminished the appearance rate by 28 and 37%. 3. The experimental data were analysed by means of a kinetic model. The parameters of the model were the epithelial permeability kF D , the serosal permeability k S F S and the sieving coefficient Φ=1−σ. The epithelial permeability was 0.115 and 0.107 for benzoic acid and salicylic acid at pH 6.2 and increased to 0.163 and 0.185 ml min−1 g−1 at pH 2.2. The serosal permeability was assumed to be identical for neutral and acidic pH and amounted to 0.046 and 0.112 ml min−1 g−1 indicating that a certain proportion of the absorbed drugs was transferred to the serosal side. The sieving coefficient was 2.92 and 2.31 at neutral pH and 3.79 and 3.56 at acidic pH. 4. The main resistance to the absorption of the two drugs is the epithelial membrane, since the effective blood flow and the unstirred layer are not ratelimiting. The high sieving coefficient for the two drugs is interpreted as indicating an interaction of drug and water molecules inside the lipid part of the cell membrane (which contains at least 30% water). The electric potential across the gut wall may contribute to the size of the sieving coefficient, if the drug molecules permeate also in the ionized form. 5. Using acidic perfusion solutions the epithelial permeability and the sieving coefficient were increased by the factor 1.3–1.5. This increase can be explained sufficiently by a facilitated entrance of the unionized drug molecules into the epithelial membrane.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 285 (1974), S. 175-184 
    ISSN: 1432-1912
    Keywords: Fenfluramine ; Rat ; Guinea Pig ; Phospholipidosis, drug-induced ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary After administration of the anorectic drug fenfluramine (40 mg/kg per day) to rats (s. c. or i. p.) and guinea pigs (p.o.) over periods of 2 to 11 weeks, electron microscopic examination was performed on lungs, liver, lymphatic tissues and peripheral blood of both species, and on adrenal glands and ovaries of rats. In rats, fenfluramine caused the following alterations (listed according to the duration of treatment): Formation of abnormal lamellated inclusions in lymphocytes and plasma cells of lymphatic tissues, appearance of “foam cells” in lung alveoli; formation of abnormal lamellated inclusions in corpus luteum, lymphocytes of peripheral blood, and in adrenal cortex. In guinea pigs, the same alterations were found in lymphocytes of spleen and peripheral blood, in hepatocytes and in lung. The present observations support the concept of a generalized phospholipidosis induced by amphiphilic compounds. The potency of fenfluramine to induce a lipidosis is, however, considerably less pronounced than that previously demonstrated for the anorectic drug chlorphentermine. This difference is suggested to be due mainly to the lower degree of amphiphilia of fenfluramine.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 282 (1974), S. 195-212 
    ISSN: 1432-1912
    Keywords: Intestinal Blood Flow ; Intestinal Absorption ; d-Galactose ; Phlorizine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Jejunal loops of anaesthetized rats were perfused with buffered solutions (pH 6.8) containing d-galactose in two concentrations: below (100 μM) and above (100 mM) blood sugar concentration. The blood flow rate, the appearance rate (in the intestinal venous blood) and the disappearance rate (from the intestinal lumen) were determined simultaneously, the accumulation in gut tissue at the end of the experiments. 2. At constant intermediate blood flow the appearance rate and disappearance rate decreased with time. A decrease of the blood flow rate from about 1.9 to about 0.3 ml min−1 g−1 diminished both the appearance and the disappearance rate. An increase of blood flow from about 0.3 to about 1.9 ml min−1 g−1 did not increase the absorption rates; even a slight decrease was observed. 3. In the presence of phlorizine (2 mM) the absorption rates and the tissue accumulation of galactose is reduced. At constant intermediate blood flow the appearance and disappearance rate increased with time. A decrease of the blood flow rate from about 1.8 to about 0.3 ml min−1 g−1 diminished the appearance rate. An increase of the blood flow rate from about 0.3 to about 1.8 ml min−1 g−1 caused an increase of the appearance rate in contrast to the experiments without phlorizine. Therefore, the different blood flow dependence of the intestinal absorption observed with actively transported substances can be attributed to their non-passive component.
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  • 5
    ISSN: 1432-1459
    Keywords: Amaurotic Idiocy ; Late infantile Neuronal ceroid-lipofuscinosis ; Mental retardation ; Electron microscopy ; Inclusion bodies ; Membrane bound neuronal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es werden die lichtmikroskopischen, histochemischen und elektronenmikroskopischen Befunde in der Gehirnbiopsie eines Frühfalles von später infantiler Form der amaurotischen Idiotie (oder einer frühen Form der Batten-Spielmeyer-Vogt-Krankheit) beschrieben. An die Membranen gebundene cytoplasmatische Einschlußkörperchen sind in einigen wenigen Neuronen vorhanden. Die morphologischen Befunde werden mit Bezug auf die Ätiologie der Erkrankung diskutiert.
    Notes: Summary The light microscopic, histochemical and electron microscopic findings in a brain biopsy of an early case of Late Infantile Amaurotic Idioty (early form of Batten-Spielmeyer-Vogt disease) are reported. Membrane bound cytoplasmic inclusion bodies are present in a small number of neurons. The morphological findings are discussed in relation to the etiology of the disease.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 14 (1974), S. 283-289 
    ISSN: 1432-0827
    Keywords: Sodium fluoride ; Osteoporosis ; Bone ; Strength ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'utilisation thérapeutique de fluorure de sodium a été recommandée dans le traitement de diverses maladies osseuses ostéopéniques. Cet emploi est basé principalement sur les effects ostéosclérotiques bien connus du fluorure de sodium, mais on connait mal son effet sur la force de résistance osseuse. L'influence de diverses concentrations de fluorure de sodium sur la force de résistance osseuse de jeunes rats soumis à des régimes riches et pauvres en calcium a été étudiée. L'administration de fluorure de sodium augmente le diamètre osseux, indiquant une stimulation de la formation de l'os périosté, mais la force de résistance osseuse est réduite ou non modifiée par l'ingestion de fluor.
    Abstract: Zusammenfassung Die therapeutische Verwendung von Natriumfluorid ist für eine Anzahl von Knochenmangel-Krankheiten empfohlen worden. Die Empfehlungen basieren hauptsächlich auf den bekannten osteosklerotischen Wirkungen von Natriumfluorid; über dessen Effekt auf die Knochenstärke ist wenig bekannt. In dieser Arbeit wurde der Einfluß verschiedener Konzentrationen von Natriumfluorid auf die Knochenstärken von wachsenden Ratten mit hoher und niederer Calciumeinnahme untersucht. Die Verabreichung von Natriumfluorid erhöhte den Knochendurchmesser, was auf eine Stimulierung der Periostbildung hinwies, die Knochenstärke wurde jedoch durch Fluorideinnahme herabgesetzt oder nicht beeinflußt.
    Notes: Abstract The therapeutic use of sodium fluoride has been recommended in a variety of osteopenic bone diseases. The recommendations are based mainly on the known osteosclerotic effects of sodium fluoride and little information is available as to its effect on bone strength. The influence of various concentrations of sodium fluoride on bone strength in growing rats on high and low calcium diets was studied. The administration of sodium fluoride increased bone diameter, indicating stimulation of periosteal bone formation, but bone strength was reduced or not affected by fluoride ingestion.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 16 (1974), S. 93-107 
    ISSN: 1432-0827
    Keywords: Dentinogenesis ; Globules ; Pyrophosphatase ; Calcification ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Three-day-old rats were fixed by perfusion with glutaraldehyde and thin slices were cut of the first molar germs. The slices were treated with EDTA and “activated” with buffered solutions containing Mg2+, Ca2+ or Zn2+. Incubation was carried out in buffered solutions (pH 8.5) containing inorganic pyrophosphate and Pb2+. In the Mg2+-activated specimens incubation products were localized to the plasma membranes in the stratum intermedium and the subodontoblastic area. Lead deposits were found on the periphery of the dentinal globules. Incubation products were more randomly distributed in Ca2+-activated specimens whereas those activated with Zn2+ displayed a deposition of lead precipitates mainly corresponding to that seen after activation with Mg2+. The findings are discussed in reference to the localization of alkaline phosphatase in the dentin-producing tissues and it is proposed that the results are indicative of the presence of an inorganic pyrophosphatase in these tissues.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 15 (1974), S. 213-220 
    ISSN: 1432-0827
    Keywords: Acid phosphatase ; Electron microscopy ; Shell Regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Acid phosphatase activity was mainly localized in the lysosomes in all the regions of the outer epithelium. The transitional portion of the outer epithelium showed more intense activity than the other regions. During shell regeneration the activity of this portion decreased to a minimum level at 12 hours and was restored to normal at 72 hours. The other regions showed no change of activity during shell regeneration. It is postulated that the acid phosphatase in the transitional protion is responsible for conferring calcifiability to the organic matrix of the shell.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 143 (1974), S. 255-262 
    ISSN: 1432-0568
    Keywords: Median eminence ; Neuro-vascular contacts ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The vascular surface of the external layer of the median eminence is composed of neuronal and glial processes. Neuro-vascular contacts are supposed to be necessary for the release of hypophysiotropic neurohormones. The present study confirms the hypothesis that the relative extent of neuro-vascular and glio-vascular contacts varies under different functional conditions of the tubero-hypophysial system. Morphometric analysis shows that in normal rats about 20% of the surface is lined by neuro-vascular contacts. After bilateral adrenalectomy the neuro-vascular contacts are enlarged to 40% whereas application of an extract of stalk-median eminence tissue is followed by a decrease of the neuro-vascular contacts to 15%. The implications of these results are discussed.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 143 (1974), S. 215-222 
    ISSN: 1432-0568
    Keywords: Lung ; Stretch receptors ; Light microscopy ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Lappenbronchien (3./6.) (Durchmesser bei mittlerer Inspirationslage 500–700 μ) von männlichen und weiblichen Wistarratten wurden licht- und elektronenmikroskopisch untersucht. Diese Bronchien entsprechen im Wandbau den mittleren Bronchioli größerer Säugetiere. Freie, verzweigte lanzettförmige Terminalfasern werden im Bindegewebe der lamina propria beschrieben. Sie sind in das elastisch muskuläre System der Bronchuswand eingebaut. Die zugehörige markhaltige afferente Nervenfaser ist verzweigt und hat einen Durchmesser von 4–6 μ. Außerdem werden efferente motorische Endigungen an der glatten Bronchialmuskulatur beschrieben. Die freien lanzettförmigen und verzweigten Terminalfasern sind möglicherweise Dehnungsrezeptoren für den Hering Breuer Reflex.
    Notes: Summary In rats the 3rd to 6th bronchi, measuring 500–700 μ in diameter during inspiration, were investigated by light and electron microscopy. The histological appearance of these bronchi is comparable to that of medium sized bronchioles of larger animals. The branched and lanceolate terminals are associated with the connective tissue of the lamina propria and the smooth muscle cell layer. In this way the terminals are bound to the myoelastic system of the bronchial wall. The myelinated afferent fiber is branched and the diameter measures about 4–6 microns. Besides afferent nerve terminals these are numerous efferent endings on the smooth muscle basement laminae. It is supposed that the described receptor represents the pulmonary stretch receptor of the Hering Breuer reflex.
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  • 11
    ISSN: 1432-0568
    Keywords: Superior cervical ganglion ; Rat ; p-Chlorophenylalanine ; 5-Hydroxytryptamine ; Catecholamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Wirkung von Parachlorophenylalanin (pCPA) auf die paraganglionären Zellen und sympathischen Ganglienzellen des Ganglion cervicale superius der Ratte wurde untersucht. pCPA beeinflußt die sympathischen Nervenzellen im Ganglion cervicale superius geringgradig. Es finden sich unspezifische Veränderungen des Golgi-Apparates und der Nissl-Schollen sowie eine Zunahme von Lysosomen. Bei langdauernder Behandlung degenerieren einzelne Ganglienzellen und Nervenfasern. Die paraganglionären Zellen sind bei Kontrolltieren durch “dense core vesicles” eines einheitlichen Typs charakterisiert. Im Laufe der pCPA-Behandlung finden sich degranulierte paraganglionäre Zellen. Die Degranulation der einzelnen Zellelemente ist jedoch variabel. Bei fluorescenzmikroskopischer Untersuchung zeigt sich nach pCPA-Applikation eine Verschiebung des Fluorescenzspektrums zum grünen Bereich hin. Die bei Kontrollen deutliche Gelbkomponente nimmt nach 6–12 Tagen ab und verschwindet schließlich nach 18–20 Tagen. Es wird diskutiert, ob die fluorescenzmikroskopischen Veränderungen aufgrund einer Hemmung der Serotoninsynthese oder aufgrund einer abgeschwächten Katecholaminsynthese entstehen.
    Notes: Summary The effect of parachlorophenylalanine (pCPA) on the paraganglionic and sympathetic nerve cells of the rat superior cervical ganglion was studied. pCPA influences the sympathetic nerve cells of the cervical ganglion to minimal extent. Unspecific changes of the Golgi apparatus and of the Nissl bodies as well as an increase in the number of lysosomes occur. An extended period of treatment causes degeneration of individual ganglionic cells and nerve fibers. The paraganglionic cells in control animals are characterized by dense core vesicles of an unitary type. During pCPA treatment degranulated paraganglionic cells are to be found. The degranulation of the individual cell elements varies. Fluorescence microscopic study after pCPA application shows a shift of the fluorescence spectrum toward green. The yellow component of the control group decreases after 6 to 12 days and disappears after 18 or 20 days. It is discussed whether the fluorescence microscopic changes are due to the inhibition of serotonine synthesis or to a decrease of the catecholamine synthesis.
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  • 12
    ISSN: 1432-0568
    Keywords: Calcitonin ; C-Cells of the thyroid and cells of the parathyroid glands ; Secondary hyperparathyroidism ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Im Verlauf ein- bis achtwöchiger Behandlung von Wistar-Ratten mit täglich 300 mMRC Einheiten Schweinecalcitonin kam es in den C-Zellen der Schilddrüse, verglichen mit denen der Kontrollserien (unbehandelte und mit Acetatpuffer allein behandelte Tiere), einerseits zu einer morphometrisch signifikanten Abahme der Zahl der Sekretgranula, während andererseits sämtliche Zellorganellen (Mitochondrie,, Golgi-Apparat und auch das granuläre endoplasmatische Reticulum) besser entwickelt waren. In den in gleichen Zeitabschnitten untersuchten Parathyroideazellen fanden wir bei mit Calcitonin behandelten Ratten Strukturveränderungen, die auf eine erhöhte Aktivität hinwiesen: Einfaltungen des Kerns, Erweiterung der Intercellularräume mit Vermehrung und Verlängerung der in diese hineinragenden Mikrovilli, bessere Ausbildung des Golgi-Apparates und des granulären endoplasmatischen Reticulums sowie eine größere Menge freier Ribosomen. Die Zahl der Sekretgranula war eindeutig höher als bei den Kontrolltieren. Der Ca ++- und Mg++-Blutspiegel zeigte während der ganzen Versuchsdauer bei allen Tieren keine statistisch faßbaren Änderungen. Die Autoren vertreten die Hypothese, daß die Aktivierung der C-Zellen durch das Auftreten eines durch die Calcitoninverabreichung hervorgerufenen sekundären Hyperparathyroidismus zustande kommt.
    Notes: Summary Male Wistar rats were injected for one to eight weeks with 300 mMRC units per day of porcine calcitonin. During this period C-cells (or “parafollicular” cells) of the thyroid gland and cells of the parathyroid glands were examined ultrastructurally. The C-cells were further studied morphometrically in animals treated with calcitonin dissolved in acetate buffer as well as in acetate buffer- and not-treated control animals. In the thyroid C cells the number of secretion granules significantly decreased following calcitonin administration, whereas the volume of all cell organelles (mitochondria, Golgi complex and granular endoplasmic reticulum) augmented. The cells of the parathyroid glands of the calcitonin-treated rats showed structural changes due to higher activity: invaginations of the nuclear envelope, enlargement of the intercellular spaces with increase in number and size of the microvilli, better development of the Golgi complex and the granular endoplasmic reticulum, larger population of free ribosomes and secretory granules. However, no significant differences in the blood calcium and magnesium levels were detected when a comparison was made of calcitonin-treated and control animals. All these observations support the hypothesis that the activation of the C-cells may result from a secondary hyperparathyroidism itself induced by the administration of moderate doses of calcitonin.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 144 (1974), S. 101-122 
    ISSN: 1432-0568
    Keywords: Subcommissural organ ; Periodically structured bodies ; Vascular permeability ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Capillaren des Subcommissuralorgans (SCO) und deren Umgebung wurden an 38 adulten Sprague-Dawley- und an 6 adulten Wistar-Ratten nach Perfusionsfixierung im Elektronenmikroskop untersucht. Saure Mucopolysaccharide wurden mit Alcianblau und Rutheniumrot, Glykoproteide mittels der Perjodsäure-Silbermethenamin-Reaktion nachgewiesen. Der Stofftransport in den Capillaren wurde mit Meerrettichperoxidase (MRP) als Tracer untersucht. Die subcommissuralen Capillaren besitzen ein ungefenstertes, vesikelarmes Endothel, das einer einfachen, durchgehenden Basallamina aufsitzt. In der Umgebung der Capillaren finden sich neben periodisch strukturierten Körpern (PSK) vereinzelt Basallamina-Labyrinthe und regellos angeordnete kollagene Mikrofibrillen. Mit der Perjodsäure-Silbermethenamin-Reaktion lassen sich Glykoproteide im Bereich der Basallamina und der nach außen anschließenden Intercellularspalten darstellen, vereinzelt auch — teils im Bereich der Basallamina, teils ihr eng angeschlossen — Gruppen parallel angeordneter, linearer Strukturen mit einem periodischen Streifenmuster. Saure Mucopolysaccharide sind nur in der lumenseitigen Glykokalyx des Capillarendothels nachweisbar. Der Aufbau der PSK aus Kollagenfilamenten erscheint sehr wahrscheinlich. Vermutungen zur Entstehung dieser hochgeordneten Strukturen werden vorgebracht. Die Traceruntersuchungen ergeben, daß unter normalen Bedingungen in den subcommissuralen Capillaren eine Blut-Hirn-Schranke (BHS) für MRP besteht, die im Endothel lokalisiert ist. Bei einem Teil der Sprague-Dawley-Ratten ist die Barriere geschädigt und der Tracer gelangt über cytopemptische Vesikel in Basallamina und Gefäßumgebung. Der Basallamina und den PSK kommt in solchen Fällen keine besondere Schranken- oder Verteilerfunktion zu. Offenbar bewirkt bei manchen Sprague-Dawley-Ratten die MRP-Injektion über die Freisetzung von endogenen biogenen Aminen aus Mastzellen eine Schädigung der BHS, was bei Wistar-Ratten nicht eintritt.
    Notes: Summary The capillaries of the subcommissural organ (SCO) and their adjacent structures of 38 adult Sprague-Dawley rats and 6 adult Wistar rats were examined in the electron microscope after perfusion fixation. Acid mucopolysaccharides were shown by Alcian Blue and Ruthenium Red, glycoproteins were identified by the periodic acid-silver methenamine technique. Horseradish peroxidase (MRP) was used as a tracer for vascular permeability. The subcommissural organ's capillaries are characterized by an unfenestrated, continuous endothelium, showing only few vesicles; the endothelium is surrounded by a single, continuous basal lamina. Adjacent to the capillaries wall there are “periodically structured bodies” (PSK), labyrinths of the basal lamina and irregularly arranged collagen fibrils. Glycoproteins are found in the basal lamina and within the intercellular clefts; in a few cases groups of parallel arranged, periodically banded linear structures are seen within or adjacent to the basal lamina. Acid mucopolysaccharides are found within the endocapillary layer of capillaries. It seems very likely that PSK represent an atypical arrangement of collagen fibrils. The formation of these structures is discussed. Under normal conditions, MRP, after intravenous injection, does not enter the perivascular space surrounding the capillaries of the SCO. A blood-brain barrier exists at the level of the capillary endothelium. In a few Sprague-Dawley rats MRP seems to alter the permeability of the capillaries. Reaction product of MRP is found within endothelial vesicles and the adjacent structures. It appears that the basal lamina and the PSK are not involved in the barrier mechanism or regulation of transport. In Sprague-Dawley rats intravenous injection of MRP seems to alter the blood-brain barrier by release of endogenous biogenic amines associated with mast cell degranulation. This effect is not observed in Wistar rats.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 146 (1974), S. 95-111 
    ISSN: 1432-0568
    Keywords: Cerebellum ; Thalamus ; Electron microscopy ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An experimental electron microscopical study has been made on the mode of termination of the cerebellothalamic projections in the cat. Supporting experimental light microscopical studies of silver impregnated sections following a large lesion of the cerebellar nuclei and light microscopical autoradiographic studies of the thalamus following injections of tritiated leucine in parts of the cerebellar nuclei, have been made as well. Following large lesions of the cerebellar nuclei, only the largest occuring type of bouton in the cat's VL and VA (type LR bouton) degenerates. Following such lesions, type LR boutons undergo a filamentous hypertrophy before becoming electrondense. One degenerating LR bouton establishes complex synapses with the dendrites of both thalamocortical relay cells and interneurons. Not all type LR boutons in VL and VA degenerate following lesions of the cerebellar nuclei. Light microscopical autoradiographic studies as well as experimental electron microscopical investigations indicate that cerebellothalamic fibers end in clusters within VL and VA, and that the areas of termination lie more rostrally within these thalamic nuclei than has been inferred from experimental studies of silver impregnated sections following lesions of the cerebellar nuclei. The findings are discussed with respect to relevant morphological and physiological data.
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  • 15
    ISSN: 1432-0568
    Keywords: Neurohypophysis ; Neuro-vascular contacts ; Neuro-glial synaptoid contacts ; Dehydration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The posterior lobe of the hypophysis consists of neurosecretory nerve fibres and glial cells, both abutting on the perivascular space of sinusoidal capillaries. Nerve fiberes and glial cells are connected with each other by a high number of synaptoid contacts. Several ultrastructural changes following dehydration have been described by other authors. This study presents the data of some morphometric investigations on normal and dehydrated rats. The relative extent of neuro-vascular contacts is not contstant; it increases significantly from 52 (±2.8)% in normal rats to 67(±1.2)% in rats with a dehydration time of 3 days. Correspondingly the extent of glio-vascular contacts is diminished. In addition, water-deprived animals show a clear increase in the number of neuro-glial synaptoid contacts with 3.1 (±0.4) per square unit nervous tissue compared to 2.1 (±0.3) per Square unit in untreated controls. These results indicate a dynamic motility of neuronal and glial elements depending on functional conditions, as was found for the external layer of the median eminence. Furthermore there seems to be a relationship between secretory activity and the number of neuroglial synaptoid contacts.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 143 (1974), S. 185-203 
    ISSN: 1432-0568
    Keywords: Basement membrane labyrinths ; Cerebral ventricles ; Development ; Rat ; Light and Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Gehirne embryonaler und neugeborener Ratten wurden im Hinblick auf die frühe Entstehung der Basalmembranlabyrinthe licht- und elektronenmikroskopisch untersucht. 1. An den Hirngefäßen embryonaler Ratten der 2. und 3. Fetalwoche kommen zwar bereits Basalmembranen vor, sub- oder interependymale Basalmembranlabyrinthe fehlen aber noch. 2. Basalmembranlabyrinthe werden mit der Perjodsäure-Bisulfit-Aldehydthionin-Methode lichtmikroskopisch ab dem 20. Tag an umschriebenen Stellen des Ventrikelsystems gefunden; elektronenmikroskopisch treten die ersten Basalmembranlabyrinthe am 12. postnatalen Tag auf. 3. Die ersten interependymalen Labyrinthe erscheinen in Erweiterung der interependymalen Spalten in der Nähe von ausgedehnten Golgifeldern. Der Labyrinthinhalt besteht aus einer feinflockigen Substanz. Diese liegt wolkenartig angehäuft gegenüber bogenförmigen Ausbuchtungen lokal verbreiterter Zellmembranen. In Ausbildung begriffene Labyrinthe zeigen eine lamelläre Gliederung. 4. Ab dem 12. postnatalen Tag treten auch an den Basalmembranen der pericapillären Zellen, in denen lichtmikroskopisch Glykoproteide nachweisbar sind, zapfenartige Duplikaturen auf. Die Zapfen sind überwiegend ependymwärts gerichtet. Verbindungen zwischen den Basalmembranzapfen und den interependymalen Basalmembranlabyrinthen werden in den ersten 30 Lebenstagen nicht gefunden. 5. Sowohl an den die interependymalen Labyrinthe begrenzenden Plasmalemmata als auch am Plasmalemm der pericapillären Zellen fallen Stachelsaumbläschen auf, deren Membran in die Zellwand eingebaut wird. Ihr Inhalt scheint in die entstehenden Labyrinthe entleert zu werden. 6. Da sich an den tubulären Enden der Doppellamellen der Dictyosomen Strukturen befinden, die den Stachelsaumbläschen morphologisch gleichen, und da im Bereich des Golgifeldes und im Cytoplasma zwischen diesem und der Zellwand zahlreiche Stachelsaumbläschen liegen, wird angenommen, daß das Material der Basalmembranlabyrinthe dem Golgiapparat entstammt und vermittels der Stachelsaumbläschen zur Zellwand transportiert wird. Bogenförmige Ausbuchtungen lokal verbreiterter Zellmembranen im Bereich entstehender Labyrinthe werden als Reste von Stachelsaumbläschen aufgefaßt, deren Membran in die Zellwand eingebaut wurde. 7. Da die phylogenetische Zunahme des Hirnmantels mit einem Verlust der langen in das Gehirn reichenden basalen Ependymfortsätze an den größten Teilen der Ventrikelwand einhergeht und niedere Tiere noch nicht über Basalmenbranlabyrinthe verfügen, wird angenommen, daß diese die Transportfunktion für Stoffe aus dem Liquor übernommen haben, die vordem nach allgemeiner Auffassung über die langen Fortsätze in das Gehirn gelangten.
    Notes: Summary The brains of embryonic and new-born rats were investigated by means of light- and electron microscopy with regard to the early formation of basement membrane labyrinths. 1. Though basement membranes are already found around the brain capillaries of embryonic rats from the 2nd week of pregnancy, sub- and interependymal basement membrane labyrinths are still absent. 2. Basement membrane labyrinths, being demonstrable for light microscopy by a periodicacid-bisulfite-aldehydethionin-method, appear around the 20th day after birth at certain places of the ventricular system. By means of electron microscopy, basement membrane labyrinths have first been detected at the 12th postnatal day. 3. The earliest interependymal basement membrane labyrinths are found in enlargements of the interependymal spaces near a distended Golgi apparatus. The contents of the labyrinths, being composed of a loose flocculent material, are of a lamellar structure. In the intercellular space the material is situated opposite bow-shaped excavations of local broadenings of cell membranes. 4. From the 12th postnatal day, plug-like duplications of basement membranes occur at the ependymal side of the pericapillar cells, which contain glycoproteids. The plugs of basement membranes are directed towards the ependymal layer. No connections between the interependymal basement membrane labyrinths and the plugs of pericapillary basement membranes exist within the first 30 days of life. 5. At the plasmalemma of ependymal cells bordering the interependymal labyrinths, and at the cell membrane of pericapillary cells, coated vesicles are to be found, which are fused with the cell membrane. The contents of these vesicles seem to be released into the developing labyrinths. 6. At the tubular ends of dictyosomes, coated vesicle-like structures can be demonstrated. In the environment of the Golgi apparatus many coated vesicles are situated; they can even be found between the Golgi apparatus and the walls of labyrinthś. Therefore the coated vesicles are considered to be transport vesicles, transporting the material which is formed in the Golgi apparatus towards the cell membrane. 7. Since the phylogenetic increase of the brain mantle is accompanied by loss of the long processes of ependymal cells that reach far into the brain, and since lower animals have no basement membrane labyrinths, it is suggested that the basement membrane labyrinths have a transport functions for material from the cerebrospinal fluid which in lower animals is assumed to be transported by the long processes of ependymal cells.
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  • 17
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    Anatomy and embryology 144 (1974), S. 1-18 
    ISSN: 1432-0568
    Keywords: Mammals ; Mole ; Ovary ; Interstitial cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Ovar des Maulwurfs wurde licht- und elektronenmikroskopisch untersucht. Der Feinbau der verschiedenen Follikel und der Keimzellen entspricht dem anderer Species. Die Granulosa wird vermutlich erst mit der Ovulation luteinisiert. Sie enthält reichlich rauhes endoplasmatisches Reticulum und Sprossen von glattem endoplasmatischem Reticulum. Die Zellen der Theka interna leiten sich von Fibrocyten ab und enthalten neben reichlich glattem ER auch granuläres ER sowie Lipidtropfen und Mitochondrien mit Cristae und Tubuli. Diese Zellen ähneln in ihrer Feinstruktur stark den Zwischenzellen des ovarialen Marks. Dieses enthält in der Marksträngen Epithelien, die einer kräftigen Basalmembran aufsitzen. Sie werden teils als embryonal persistierende Vorstufen von Granulosa- oder Sertoli-Zellen, teils als Granulosasprossen aus der Rinde gedeutet. Für die Zwischenzellen des Marks erscheint eine Analogie mit den Hiluszellen des menschlichen Ovarialmarks bzw. eine Homologie mit den Leydig-Zellen des Hodens zweifelhaft. Als mögliche Quelle für diesen Zelltyp werden neben embryonal liegengebliebenen Anteilen auch Thekakeile und Epoophoronzellen sowie Fibroblasten diskutiert. Neben einer Steroid-synthese dürfte ihnen eine Reserve- und Speicherfunktion zukommen.
    Notes: Summary In order to make possible comparison between relatively primitive and relatively specialized gonads, the ovary of the mole was studied by light and electron microscopy. The ultrastructure of primary, secondary and tertiary follicles and of the germ cells is similar to that of other species. The granulosa cells of secondary and early tertiary follicles contain abundant rough endoplasmic reticulum and a small number profiles of smooth endoplasmic reticulum. The cells of the theca interna, which develop from simple fibrocytes are rich in smooth and rough endoplasmic reticulum and contain many lipid droplets and mitochondria, which possess both cristae and tubuli mitochondriales. At the time of ovulation, the granulosa cells are luteinized and their ultrastructure changes correspondingly. The medulla of the ovary is composed of the medullary cords and the interstitial cells. The medullary cords are solid epithelial cords, which are surrounded by a prominent basement membrane. They may be derived from embryonic precursors of granulosa—or Sertoli-cells or bud from the cortical zonae granulosae. There is a striking morphological similarity between the theca and interstitial cells. The interstitial cells of the ovarian medulla differ from the hilus cells of the human ovary and the Leydig-cells of the testis. They may develop either from embryonic rudiments of Leydig—or hilus-cell precursors, or bud from the theca or the epoophoron, or they may develop from fibrocytes. In addition to their suggested activity in steroid biosynthesis, the interstitial cells may have a trophic or storage function.
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  • 18
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    Anatomy and embryology 144 (1974), S. 75-83 
    ISSN: 1432-0568
    Keywords: Colonic mucosa ; Mouse ; Vacuolated cells ; Electron microscopy ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Swiss ICR adult male mice were used to analyse regional morphologic differences in the mucosa of the colon. The three cell types recently described in the descending colon of the mouse were also observed in the transverse and in the ascending colon. However the vacuolated cells of the crypts have presented different morphological characteristics depending on their localisation. In the ascending colon, they exhibited small supranuclear vesicles in contrast to the large vesicles observed in the descending colon. Several cell combining features of argentaffin-vacuolated, goblet-vacuolated and goblet-argentaffin cells have been observed. Furthermore a special type of granule referred to as a secondary lysosome was observed in the peripheral area of the typical goblet cells.
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  • 19
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    Anatomy and embryology 144 (1974), S. 173-186 
    ISSN: 1432-0568
    Keywords: Hippocampus ; Neurogenesis ; Autoradiography ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summay The prenatal ontogeny of the hippocampus, including the anterior continuation and induseum griseum, was examined in the rat by means of tritiated thymidine autoradiography. The neurons of the anterior continuation formed between the 16th and 18th days of embryonic development. The neurons of the induseum griseum were formed on the 16th and 17th days of gestation. The pyramidal cells of ammon's horn were formed during the 16th, 17th, 18th, and 19th days of embryogenesis but were preceded by the large interneurons of the stratum lacunosum-moleculare which formed on days 15 and 16 of embryonic life. The granule cells of the superficial layers of the stratum granulosum formed during the 20th, 21st, and 22nd days of gestation.
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  • 20
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    Anatomy and embryology 145 (1974), S. 187-196 
    ISSN: 1432-0568
    Keywords: Human skeletal muscle ; Sarcolemma ; Isolation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An isolation procedure for sarcolemma of human skeletal muscle is described. The method includes the possibility to prepare sarcoplasmic reticulum from the same muscle fibres. Electron microscopy reveals a homogeneous final fraction of 80–90% myofibre enveloping membranes contaminated by blood vessel membranes. The typical three-laminar composition of isolated sarcolemma is demonstrated. The mechanism of muscle fibre emptying is discussed.
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  • 21
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    Anatomy and embryology 145 (1974), S. 223-226 
    ISSN: 1432-0568
    Keywords: Rat ; Liver ; Bile ducts ; Cilia ; Scanning Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Numerous cilia have been demonstrated by SEM in cells of rat perilobular and portal bile ducts and ductules. Generally these cilia appear as long, cylindrical evaginations of the plasma membrane. Some of them are so long that, curving and twisting at many points, they cross the ductal lumen. It has been suggested that they may be related to a continual mixing up and propulsion of the bile product down the biliary tree.
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  • 22
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    Anatomy and embryology 145 (1974), S. 169-186 
    ISSN: 1432-0568
    Keywords: Renal innervation ; Rat ; Peripheral nerves ; Neuroeffector zones ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der Rattenniere werden die muskelzellhaltigen arteriellen Gefäße und der juxtaglomeruläre Apparat innerviert. Blutgefäße mit Pericyten, porenhaltige Capillaren sowie die Tubuli der Rinde und des Markes werden nicht von Nervenfasern begleitet. Ganglienzellen wurden in der Rattenniere nicht beobachtet. Periphere Nerven mit einem ein-bis zweischichtigen Perineurium kommen im paravasalen Gewebe der Interlobar- und Arcuata-Arterien vor; sie enthalten neben zahlreichen marklosen Nervenfasern gewöhnlich auch 2–4 markhaltige. Nervenfaser-Bündel ohne perineurale Scheide finden sich im paravasalen Gewebe der Arcuata- und Interlobular-Arterien. Darüber hinaus sind in unmittelbarer Nachbarschaft der großen Arterien (Interlobar-, Arcuata- und Inter-lobular-arterien) und der Vasa afferentia marklose Nervenfasern und freie Axone vorhanden, die auch die proximalen Abschnitte der Vasa efferentia der subcapsulären und intermediären Rindenschicht begleiten. Im Nierenmark werden die juxtamedullären Vasa efferentia und die Arteriolae rectae innerviert; marklose Nervenfasern und freie Axone sind nur bis zur Außen-Innenstreifen-Grenze nachweisbar. Die Innervation der muskelzellhaltigen arteriellen Gefäße erfolgt durch aufgetriebene Axonabschnitte (Neuroeffektor-Zonen), die vorwiegend agranuläre Vesikel enthalten. Diese Strukturen liegen stets an der Grenze von Adventitia und Media bzw. Elastica externa; zwischen den glatten Muskelzellender Media wurden keine vesikelhaltigen Axonabschnitte gefunden. Als minimaler Abstand zwischen den vesikelhaltigen Axonabschnitten und den von einer Basalmembran umschlossenen glatten Muskelzellen (neuromuskuläre Distanz) wurden 600 Å gemessen. Die vorliegenden Ergebnisse werden mit den fluoreszenzmikroskopischen und histochemischen Untersuchungen über die adrenerge und cholinerge Innervation der Niere verglichen. Die sich aus diesem Vergleich ergebenden Probleme und funktionellen Konsequenzen für die Innervation der Niere sowie die Natur der cholinergen Fasern (afferente oder postganglionäre parasympathische Fasern) werden diskutiert.
    Notes: Summary The innervation of the rat kidney is defined by a system which supplies those arterial blood vessels whose walls contain smooth muscle cells and the juxtaglomerular apparatus. Vessels containing pericytes, or those vessels composed of an endothelium only, as well as the tubules of both the cortex and medulla, are not innervated. Furthermore, ganglion cells do not occur in the rat kidney. The nervous apparatus of the rat kidney consists of peripheral vegetative nerves, ensheathed by a perineurium, with 2–4 myelinated fibers running in the paravasal tissue of the interlobar and arcuate arteries, and of nerve bundles without a perineurial sheath in the paravasal tissue of the arcuate and interlobular arteries. Non-myelinated fibers and free axons occur in the immediate vicinity of the great arteries (interlobar, arcuate, and interlobular) and the vasa afferentia. Nerve fibers and free axons are also seen in the vicinity of only the proximal parts of those vasa efferentia which supply the cortical capillary plexus. The arteriolae rectae of the medulla, and their vasa efferentia, from which they arise, are innervated by non-myelinated fibers and free axons which accompany these arterial vessels only to the boundary of the outer and inner stripe of the outer zone of the medulla. The functional innervation of those vessels with smooth muscle cells results from neuro-effector zones which predominantly show agranular vesicles. These structures were never seen between the smooth muscle cells within the media; the minimum neuromuscular distance was 600 Å. The present findings are correlated with the lightmicroscopically demonstrated adrenergic and cholinergic innervation. The resultant problems and functional consequences of the innervation of the kidney, especially the nature of the cholinergic fibers (afferent or post-ganglionic parasympathetic fibers) are briefly discussed.
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  • 23
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    Anatomy and embryology 144 (1974), S. 85-100 
    ISSN: 1432-0568
    Keywords: X zone ; Electron microscopy ; Development ; Adrenal ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The postnatal development and involution of the X zone in the mouse adrenal cortex of both sexes were examined using the light and electron microscopes. At 0–5 days of age, no special cell group could be distinguished for the developing X zone in the inner cortex. The inner cortical cells contained spherical or ellipsoidal mitochondria with vesiculotubular cristae, vesiculotubular smooth endoplasmic reticulum (sER) and electron-lucent lipid droplets. The first sign of the developing X zone was the appearance of small groups of cells in juxtamedullary region differing from the cells in other part of inner cortex at 8 days. The electron microscopy showed that such cells contained nuclei of somewhat irregular outline and some parallel stacks of flattened sER. At 10–11 days, a thin layer of small eosinophilic cells were clearly identified as the developing X zone light microscopically in both sexes. Electron microscopically, the X zone cells showed a much dense cytoplas, which contained abundant sER, many mitochondria and numerous ribosomes. The typical X zone cells were characterized by the formation of peculiar mitochondrial complexes and whorled pattern of the sER. Mitoses were often found in the X zone, where mitotic cells even contained the whorled sER and bizarre mitochondria characteristic of the typical X zone cells. In the male the X zone rapidly involuted and might disappear by 30 days of age, whereas in the female X zone persisted as a thicker layer with the earlist sign of fatty degeneration. The origin of the X zone cell and the process of formation of its characteristic organelles are discussed.
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  • 24
    ISSN: 1432-0568
    Keywords: Motor nerve terminals ; Methylene blue stain ; Hindlimb muscles ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary With methylene blue stain, three morphological types of motor nerve terminals were distinguished in hindlimb muscles (extensor digitorum longus, semitendinosus, soleus, and tibialis anterior muscles) of rat. Type A terminals possess many long thin branches with numerous minute swellings, type C ones possess few and thick terminal branches with few large swellings, and type B ones possess intermediate characteristics. The frequencies of occurrence of these types are characteristic for each muscle and differ between different hindlimb muscles. Specifically, soleus muscle contains a much higher proportion of type B terminals than other hindlimb muscles, and the superficial part of tibialis anterior muscle contains a higher proportion of type A terminals and a lower proportion of type C ones than the deep part. The frequencies of occurrence of types A, B, and C terminals closely parallel the frequencies of “white”, “intermediate”, and “red” muscle fibers (as determined by a fat stain), respectively, in the different muscles. As also suggested previously for the diaphragm, it is concluded that three morphological types of motor nerve terminals each may innervate one of three types of muscle fibers.
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  • 25
    ISSN: 1432-0568
    Keywords: Pantothenic acid deficiency ; Corticotropin-releasing factor ; Corticoids ; Histologie ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the outer layer of the rat median eminence “Gomori-positive” granules occur which are assumed to be the morphological correlate of the corticotropin-releasing factor (CRF). The present study was carried out in order to establish whether the amount of these CRF-granules is influenced by a pantothenic acid (PA)-deficiency, which is known to result in an inhibition of corticosteroid production. Female SPF Wistar rats were used. PA-deficiency was induced by PA-free nutrition and/or administration of the PA-antagonist Ω-methyl-PA. Corresponding experimental groups were given either tap water or a solution of 1% NaCl and 5% glucose in tap water to drink. In rats fed with a diet free of PA and in addition treated with Ω-methyl-PA a severe disturbance of the corticoid balance developed within 6 weeks. The corticosterone production was depressed to about 11–16% of the control values. The adrenal cortex showed necrotic changes which either involved the whole parenchyma or were confined to the inner zones. In those animals in which a subcapsular region, in its extent corresponding to the zona glomerulosa, remained intact, an augmentation of the CRF-granules was observed. In those animals, however, in which the whole adrenal cortex was damaged, the amount of CRF-granules did not increase. Administration of the 1% NaCl containing drinking fluid did not influence the augmentation of the CRF granules, but had a protective effect on the development of necrotic changes in the zona glomerulosa of the adrenal cortex. The findings show that a functional relationship exists between the inner zones of the adrenal cortex and the CRF-granules in the median eminence.
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  • 26
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    Anatomy and embryology 147 (1974), S. 19-34 
    ISSN: 1432-0568
    Keywords: Gonads/embryology ; Swine/embryology ; Sex determination ; Electron microscopy ; Sex characteristics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pig embryos aged 21–22 days (d) were obtained from artificially inseminated sows for an ultrastructural study of the development and sex differentiation of the gonadal ridge. The chromosomal sex of the embryos was identified by a chromosome analysis. At the age of 21 d the gonadal ridge consisted of three different tissue: the surface epithelium, the primitive cords, and the mesenchyme. The surface epithelial cells contained elongate mitochondria with lamellar cristae, granular endoplasmic reticulum (GER), the Golgi complex, free polysomes, coated vesicles and fine filaments. The epithelium was continuous with the primitive cords, which were composed of ultrastructurally similar cells. The epithelial basal lamina followed the cord surface, but covered it incompletely. Primordial germ cells (PGC) were located under the surface epithelium in the mesenchyme and in the cords. The nucleus with a prominent nucleolus, and the large mitochondria were round. The cytoplasm contained a pair of centrioles, the Golgi complex, solitary lamellae of the GER, free polysomes, lipid droplets and some coated vesicles. The PGC entered the gonadal cords before these were surrounded by the continuous basal lamina. A day later (22 d) the number and length of the cords were increased. The PGC were more frequent and seen also in deeper layers. All the structures studied at the age of 21–22 d showed that the gonadal ridge also at the ultrastructural level is at the sexually indifferent stage.
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  • 27
    ISSN: 1432-0738
    Keywords: Alcohol, Ethyl ; Absorption ; Elimination ; Alcohol Oxidoreductases ; Hepatitis, Toxic ; Transaminases ; Glutamate Dehydrogenase ; Guinea Pig ; Rat ; Äthylalkohol ; Resorption ; Elimination ; Alkoholdehydrogenase ; Hepatotoxicität ; Transaminasen ; Glutamatdehydrogenase ; Meerschweinchen ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die maximalen Blutalkoholkonzentrationen nach oraler Gabe von 6,4 g/kg Äthanol in Form einer 40%igen Lösung (v/v) betrugen bei nicht nüchternen Meerschweinchen 6,8±0,3 mg/ml, bei nicht nüchternen Ratten dagegen nur 2,1±0,2 mg/ml. An nüchternen Tieren führte eine orale Alkoholbelastung von 4,8 g/kg zu maximalen Blutalkoholspiegeln von 6,3±0,2 mg/ml bei den Meerschweinchen und 3,7±0,3 mg/ml bei den Ratten. Intravenös injizierter Alkohol (1 g/kg) wurde demgegenüber von beiden Species mit der gleichen Geschwindigkeit eliminiert (275 mg/kg · Std), und die auf das Körpergewicht bezogene ADH-Aktivität der Leber war bei den Meerschweinchen um 20% größer als bei den Ratten. Die Resorption von Äthanol erfolgt somit bei Ratten erheblich langsamer als bei Meerschweinchen. Dies dürfte darauf beruhen, daß konzentrierte Alkohollösungen die Magenentleerung der Ratte stark verzögern. Niedriger konzentrierte Alkohollösungen werden von der Ratte schneller resorbiert; jedoch waren auch nach Gabe von 10%igem Alkohol die maximalen Blutalkoholspiegel bei Ratten noch um 36% niedriger als bei Meerschweinchen. Bei den Meerschweinchen waren nach oraler Gabe von 4,8 bzw. 6,4 g/kg Äthanol die Serumaktivitäten der GOT, GPT und GLDH erhöht; ein Anstieg der SGOT trat schon nach 1,6 g/kg Äthanol auf. Demgegenüber kam es bei Ratten nach 6,4 g pro kg Äthanol p.o. nur zu geringfügigen Aktivitätserhöhungen der Serumtransaminasen, während die Serumaktivität der GLDH unverändert blieb. Vacuolige Degeneration war das morphologische Substrat der durch Äthanol bei Meerschweinchen und Ratten ausgelösten Leberschädigung. Während diese Veränderung bei Meerschweinchen bereits nach einer Äthanoldosis von 1,6 g/kg auftrat, wurde sie bei Ratten erst nach 6,4 g/kg beobachtet. Schlußfolgerung: Das Meerschweinchen ist für Untersuchungen zur Toxicität von Äthanol besser geeignet als die Ratte.
    Notes: Abstract In fed guinea pigs, an oral dose of 6.4 g/kg of ethanol given as a 40% solution (v/v) produced a maximal blood alcohol level of 6.8±0.3 mg/ml, whereas in fed rats, blood alcohol levels after the same dose did not exceed 2.1±0.2 mg/ml. Maximal blood alcohol levels in fasted animals after an oral load of 4.8 g/kg of ethanol were 6.3±0.2 mg/ml in guinea pigs and 3.7±0.3 mg/ml for rats. However, i.v. injected ethanol (1 g/kg) was eliminated at the same rate in both species (275 mg per kg · h), and ADH activity of the liver related to body weight was by 20% greater in guinea pigs than in rats. Therefore, absorption of ethanol occurs at a much slower rate in rats than in guinea pigs. This is possibly due to the fact that high ethanol concentrations strongly delay emptying of the rat stomach. Lowering the ethanol concentration accelerates absorption rate in the rat. However, even after gavage of a 10% solution peak levels of blood alcohol were still lower by 36% in rats than in guinea pigs. In guinea pigs, increased serum activities of GOT, GPT, and GLDH occurred after an oral dose of 4.8 g/kg or 6.4 g/kg of ethanol, respectively. SGOT already increased after 1.6 g/kg of ethanol p.o. After 6.4 g/kg of ethanol given to rats serum transaminase levels increased only slightly, and GLDH activity not at all. Vacuolar degeneration was the morphological substrate of ethanol-induced liver damage in guinea pigs and rats. In guinea-pigs, it occurred already after 1.6 g/kg of ethanol, whereas in rats only after 6.4 g/kg. In conclusion, the guinea pig seems to be better suited for research on alcohol toxicity than the rat.
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  • 28
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    Experimental brain research 21 (1974), S. 107-112 
    ISSN: 1432-1106
    Keywords: Preoptic units ; Thermosensitivity ; Mean firing rate ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mean firing rates (per 10 sec) of preoptic neurons of the rat were recorded at normal temperature and after central warming and cooling. Thermosensitivity was determined according to the reactions of the mean firing rate. In compatibility with results from other animals we obtained the following percentages (52 neurons): 23% warm-sensitive, 13% cold-sensitive, 64% non-thermosensitive neurons. However, it turned out that a lot of interesting special effects are not taken into account, using exclusively the criterion “increasing/decreasing/constant mean firing rate”. Particularly we observed long lasting adaption processes and stationary non-linear effects as well as striking oscillations which were dependent on the thermal stimuli, while the mean interval value remained constant.
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  • 29
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    Experimental brain research 20 (1974), S. 181-192 
    ISSN: 1432-1106
    Keywords: Locus ceruleus ; Cerulo-cortical tract ; Ascending reticular fiber ; Rat ; Fink-Heimer method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to demonstrate the ascending projection from the locus ceruleus by degeneration silver method, the nucleus was destroyed unilaterally in rats and the brains were stained by a modified Fink-Heimer method following various survival times. Additional experiments included the bilateral destruction of the locus ceruleus and the administration of 6-OH-DOPA. For the demonstration of degenerated terminals in the cerebral cortex it is essential to choose an optimal survival time of 4 or 5 days, keep the time of fixation below 1 week, and perform treatments with permanganate and with silver at 37°C. The trajectory and distribution of the cerulo-cortical tract as revealed by the silver degeneration methods is in agreement with the results of the histofluorescence method, with some minor differences. The ascending fibers run through Forel's tegmental fascicle, turn rostro-ventrally to the subthalamus, enter and cross the internal capsule, pass through the ventral part of the caudate-putamen and distribute to the entire cerebral cortex. The tract is mainly ipsilateral, though some fibers are crossing.
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  • 30
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    Acta neuropathologica 28 (1974), S. 25-35 
    ISSN: 1432-0533
    Keywords: Chronic Lead Intoxication ; Rat ; Ultrastructure ; Microglia ; Pericytes ; Monocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Wistar rats of both sexes and the same litter were exposed to chronic lead intoxication from birth untill sacrifice 9 months later. Lead was administered as 0.4% solution of lead nitrate in drinking water. Samples from the parietal brain cortex were examined electron microscopically following intracardiac perfusion with paraformaldehyde-glutaraldehyde solution. Similar changes were observed in the microglial cells and the vascular pericytes whereas all the other tissue elements appeared intact. Both cell types hypertrophied, the microglia assumed characteristic spindle or rod shape, the cell organelles increased, the microglial endoplasmic reticulum widened strongly and a large number of lipid inclusions appeared. The latter consisted of large lipid droplets of varying size and shape, containing multiple zones of low density, and a dense component with a coarse granular structure. The similarity in the response of both cell entities to the lesion as well as some probable functions of microglial cells and their relationship to vascular pericytes are discussed.
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  • 31
    ISSN: 1432-0533
    Keywords: Cholesterol Inhibitors ; Cerebrum ; Neuronal Inclusions ; Oligodendroglial Degeneration ; Rat ; Abnormal Sterols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Wistar strain of rats received daily intraperitoneal or oral administration of Triparanol, 250 mg per kg of body weight or 20,25-diazacholesterol either 30 mg or 60 mg per kg of body weight starting at the age of 5 days old. Prominent intracytoplasmic osmiophilic inclusions identical to those found in the rats treated with AY9944 (Suzukiet al., 1973) and degeneration of myelin sheaths and oligodendroglia were seen in the myelinating white matter of rats sacrificed after 3, 6, and 9 injections of Triparanol. In diazacholesterol-treated animals, a few identical inclusions were seen in the cortical neurons but only slight changes were seen in oligodendroglia. Biochemical analysis of the brains of the rats receiving Triparanol revealed a large accumulation ofΔ 7,24-cholestadiene-3β-ol and lesser amounts of desmosterol. The brains of the animals treated with diazacholesterol revealed massive accumulation of desmosterol and a minor sterol component, probablyΔ 5,7,24-cholestatriene-3β-ol. Since AY9944, which results in a massive accumulation of 7 dehydrocholesterol (Δ 5,7-cholestadiene-3β-ol) and two other sterols,Δ 7,24-cholestadiene-3β-ol andΔ 5,7,24-cholestatriene-3β-ol, will produce identical neuropathological lesions to those seen in Triparanol treated animals, and since the lesion produced in diazacholesterol treated animals was very slight, there appears to be a correlation between the presence of sterols with a double bond at the 7-position and neuropathological lesions in young rats.
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  • 32
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    Acta neuropathologica 27 (1974), S. 25-32 
    ISSN: 1432-0533
    Keywords: Experimental CNS Tumours ; Nitrosomethylurea ; Ethylnitrosourea ; Primary Cultures ; Tumour Classification ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary By means of the explant technique a series of primary tumours induced by methylnitrosourea (MNU) or ethylnitrosourea (ENU) in the brain of rats were cultured in vitro. The morphology of isomorphic oligodendrogliomas, astrocytomas, glioblastomas and sarcomas under in vitro conditions is described. All these neoplasias show a very distinct morphological picture and growth behaviour, thus permitting their classification. Most of the tumours tend to anaplastic changes during longer cultivation, but in some cases, preferably in well differentiated gliomas, the cytological properties are maintained even during longterm cultivation. The role of anaplasia and intermingling of different neoplastic cell types in experimental tumours are discussed.
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  • 33
    ISSN: 1432-0533
    Keywords: Allergic Encephalomyelitis ; Organ Culture ; Brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experimental allergic encephalomyelitis (EAE) developed in 15 of 30 rats injected with a mixture of Freund's adjuvant and homogenized guinea pig brain, and killed after 6–29 days. The incidence and severity of the disease increased with time after inoculation and in 2 animals involvement of the epiphysis, not previously reported in EAE, was detected. Toxic effects on cells in cultured adult rat cerebellar cortical tissue were produced by exposure for 24 h to the sera of rats killed 12–29 days after inoculation either with the antigenic suspension or with adjuvant alone. Severe toxicity to axons (widespread fragmentation) was produced only by the sera of animals injected with antigenic inocula and killed 17–29 days later. Severe axonal toxicity was not, however, correlated with the presence of EAE in the rats from which the sera were taken. It was not possible to assess myelinotoxic effects in the system used. It is suggested that the organ culture technique may detect the presence in the sera of inoculated animals of toxic principles which, owing to the blood-brain barrier, do not normally contribute to the pathogenesis of EAE.
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  • 34
    ISSN: 1432-2072
    Keywords: Rat ; Successive Discrimination ; Conditioned Avoidance Response ; Nerve Impulses ; α-Methyltyrosine ; Tetrabenazine ; l-Dopa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of the administration of l-Dopa, 10 or 100 mg/kg i.p., on the α-methyltyrosine methylester HCl (α-MT; 250+50 mg/kg i. p.) or tetrabenazine (TBZ; 2 mg/kg i.p.)-induced suppression of a successive discrimination-conditioned avoidance task has been studied. It was found that administration of the high l-Dopa dose resulted in a reversal of the α-MT- or TBZ-induced suppression of the avoidance behaviour, although the discrimination was lost. Restoration of the avoidance behaviour and the correct discrimination was obtained with the low l-Dopa dose after α-MT but not after TBZ. The difference in the behavioural response to l-Dopa after α-MT as compared to the response obtained after TBZ is discussed in terms of the availability of the catecholamines formed from l-Dopa for release by the nerve impulses. Biochemical determinations of brain noradrenaline and dopamine were made in parallel. Further, a simple and reliable method for the aquisition of a successive discrimination in the rat is described.
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  • 35
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    Psychopharmacology 39 (1974), S. 237-244 
    ISSN: 1432-2072
    Keywords: Antagonism ; Fixed Interval ; Scopolamine ; Physostigmine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of this research was to determine if 2 drugs, scopolamine and physostigmine which have opposite effects on cholinergic transmission also produce opposite effects on fixed-interval (FI) performance. Scopolamine and a wide range of doses of physostigmine were administered singly and concurrently to a number of rats responding on a FI 2 min schedule. Scopolamine produced a disruption in FI curvature which could be antagonized by physostigmine, but physostigmine by itself produced no consistent change.
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  • 36
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    Psychopharmacology 36 (1974), S. 323-335 
    ISSN: 1432-2072
    Keywords: Methamphetamine ; Rat ; Conditioned ; Aversion ; Space ; Saccharin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Three experiments were performed on Sprague-Dawley derived rats in which 3.0 mg/kg, i.p., injections of methamphetamine were paired with either, (1) a distinctive spatial enclosure, i.e., either a black or gray portion of a shuttle box with discriminably different flooring, (2) the enclosure plus 0.1% saccharin solution availability in the home cage, or (3) the enclosure plus 0.1% saccharin solution availability in that area. Following three drug pairings which alternated with saline injections paired with a different enclosure or enclosure plus H2O availability, a choice of either spatial (1), or spatial plus gustatory stimuli (2,3) which included the original CS's, were presented under non-drug, non-injection conditions. Control groups received saline injections each day under identical conditions. No aversion to the enclosed area, which had been paired with the drug was demonstrated under (1), gustatory (P=0.005) but not spatial aversion was in evidence in the second paradigm, and spatial (P=0.01) and gustatory (P〈0.01) aversion was exhibited in the last study. It was concluded that subsequent aversion to distinctive spatial enclosures following methamphetamine injections was not as strong an effect as similar aversions to gustatory stimuli. Furthermore, the effect only obtained to neutral and not to preferred spatial areas at the dose level tested and in the apparatus used in those studies.
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  • 37
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    Psychopharmacology 40 (1974), S. 91-99 
    ISSN: 1432-2072
    Keywords: Lithium ; Social Behaviour ; Sex ; Novelty ; Photographs ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of lithium chloride on the social behaviour of male and female rats were measured in unfamiliar and familiar test situations using a photographic technique. Lithium-treated females showed an increase in body contact and a decrease in social distances in comparison with saline-treated controls in both test conditions. Males administered lithium showed increased corner occupancies in the novel test setting while in the familiar test they showed decreased body contact and increased average group social distance in comparison with the saline condition. Further tests in an exploration box confirmed that lithium decreased the general environmental responsiveness of male rats. The results are discussed with reference to the anti-aggressive effect of lithium.
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  • 38
    ISSN: 1432-2072
    Keywords: LSD-25 ; UML ; 5-HT ; Brain ; Platelets ; Behaviour ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Factorial analysis of rat cerebral 5-HT values observed following intraperitoneal LSD-25 and UML (1-methyl-d-lysergic acid butanolamide) showed that the highly significant decrease induced by both drugs was independent of dose and that the effect of both drugs was the same. Increased platelet 5-HT values were also obtained with each drug. These findings suggest that the psychotomimetic effect of LSD-25 is not due to changes in cerebral 5-HT, since a relationship can probably be postulated between such an effect in man and the effect of LSD-25 on conditioned behaviour in the rat. It is also felt that the fact that these drugs decrease and increase cerebral and platelet values respectively may be of assistance in the interpretation of data relating to platelet 5-HT patterns in man under psychiatric conditions and during treatment with psychotropic drugs.
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  • 39
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    Psychopharmacology 37 (1974), S. 91-100 
    ISSN: 1432-2072
    Keywords: Ethanol ; Brain Serotonin Turnover ; Tolerance ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In rats treated acutely and chronically with ethanol, brain serotonin (5-HT) turnover was determined by measuring in the same animals the rate of accumulation of 5-HT and the rate of decline of 5-hydroxyindoleacetic acid (5-HIAA) in the brain after administration of the MAO inhibitor pargyline-HCl. In the acute study, 5-HT turnover was not altered after a single 4 g/kg oral dose of ethanol. In two separate studies, it was shown that chronic administration of ethanol in the form of a liquid diet for 32 days also did not alter brain 5-HT turnover, even when the rats had developed a significant degree of tolerance to the motor-impairing effects of ethanol. These results suggest that tolerance to ethanol is unrelated to any change in brain 5-HT turnover.
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  • 40
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    Psychopharmacology 37 (1974), S. 249-254 
    ISSN: 1432-2072
    Keywords: Chlorpromazine ; Rat ; Social Interaction ; Exploration ; General Motor Activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract When two animals were placed in a hole-board the number of headdips made by each rat was twice the number made when tested alone, but was the same for pairs of drugged (2 mg/kg chlorpromazine) and undrugged rats, and for pairs where only one rat was drugged. This contrasts with the reduction of headdipping produced by chlorpromazine in single animals. However, chlorpromazine still reduced general motor activity, regardless of whether the partner was drugged or not. The activity of the undrugged rats was affected by the partner's state and was lower when the partner was drugged.
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  • 41
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    Psychopharmacology 39 (1974), S. 309-314 
    ISSN: 1432-2072
    Keywords: Avoidance ; Drug ; Psychotropic ; Rat ; Sidman Schedule ; Sulpiride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Sulpiride, a new psychotropic drug with neuroleptic activity, was administered to rats in a Sidman avoidance schedule. Doses ranging from 1 to 80 mg/kg resulted in the animal receiving fewer shocks. This effect was not correlated with an increase of responding and seemed unrelated to the suppressing action abruptly observed at high doses (i. e. 150 to 200 mg/kg). These results differ from those classicaly obtained with other neuroleptics.
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  • 42
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    Psychopharmacology 35 (1974), S. 341-352 
    ISSN: 1432-2072
    Keywords: 6-Hydroxydopa ; Rat ; Behaviour ; Biogenic Amines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The influence of 6-hydroxydopa (6-HDP) injected into the lateral ventricles of rat brain on the behaviour of animals was examined. The level of noradrenaline (NA), 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in discrete areas of the brain was also measured. 6-HDP was injected in a dose of 100 or 150 Μg into both lateral ventricles, or in a dose of 200 Μg into the right lateral ventricle. Immediately after 6-HDP injection, circling movements, convulsions, aggressive behaviour, and Stereotypic activity were seen. These components of behaviour were most obvious during the first hour after injection of 6-HDP. During one month after 6-HDP administration the behaviour of rats did not differ significantly from the behaviour of control animals, only very subtle differences in behaviour being seen. The dose of 150 Μg of 6-HDP caused aphagia and loss of body weigth during the first 5 days after treatment. 6-HDP also caused hypothermia. 20 min after administration of 200 Μg of 6-HDP a decrease of the NA level but no changes in the 5-HT level in the brain cortex were seen. The same changes were observed 1 month after 6-HDP treatment. The dose of 150 Μg of 6-HDP decreased the NA level in the brain cortex, cerebellum, mesencephalon and brain stem 5 days after treatment. 5-HT content was not changed and the 5-HIAA level was increased in the same brain areas. The dose of 100 Μg of 6-HDP, 2 weeks after the treatment decreased the content of NA in the brain cortex, cerebellum, hypothalamus and brain stem without changes in 5-HT content. 5-HIAA level was elevated only in the brain stem. It is concluded that 6-HDP is a long-acting potent depletor of NA in rat brain. There is a different sensitivity of brain areas to the depleting effect of 6-HDP. 6-HDP does not deplete the 5-HT content of discrete areas of brain but increases the level of 5-HIAA. 6-HDP causes distinct behavioural changes shortly after the treatment. It does not change the behaviour of rats between 1 and 30 days after its administration.
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  • 43
    ISSN: 1432-2072
    Keywords: Rat ; Chlordiazepoxide ; Diazepam ; Extinction ; Avoidance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a one-way avoidance task with rats, injections of Librium (chlordiazepoxide) following avoidance acquisition resulted in prolonged resistance-to-extinction of the avoidance response. This effect occurred regardless of whether the rats had had prior experience with Librium or whether they were naive with respect to the drug. The same results were found with the same task when low doses of Valium were used. However, at a higher dosage an “extreme reaction” of either no responding or a high number of responses to extinction occurred in the naive animals. The Librium and Valium effects were compared to similar effects obtained using ethanol and hashish resin. These results indicate that the novelty hypothesis as originally stated by Amit and Baum cannot be supported because experience with the drugs prior to avoidance training did not attenuate the drug effect on avoidance.
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  • 44
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    Pflügers Archiv 351 (1974), S. 323-330 
    ISSN: 1432-2013
    Keywords: Uricase ; Urate ; Allantoin ; Liver ; Kidney ; Microperfusion ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. In vivo uricase activity was tested in rats by injection of 2-C14 urate and measurement of the total C14 activity and the fractional activities of allantoin, allantoic acid and urea in samples of blood and urine. In control animals, 5 min after the injection, 70% of the plasma tracer was already present in the form of allantoin. No allantoic acid and urea were produced. Intestinectomy had no measurable influence on uricase activity. On the other hand, hepatectomy or ligation of the hepatic artery combined with subtotal viscerectomy did abolish uricase activity almost completely. 2. Following microinjections into proximal tubules of Ringer solution containing 2-C14 urate, urine samples during early recovery mainly contained labelled urate, whereas in later samples the fraction of labelled allantoin increased. About 12 min after the microinjection the urine of both kidneys contained equal amounts of tracer mainly in the form of allantoin. 3. When segments of proximal tubules were perfused with an equilibrium solution containing tracer amounts of C 14 urate, no urate was metabolized during its passage through the proximal tubule. 4. C 14 urate was offered from the peritubular capillaries and samples of tubular fluid were analyzed, Again, all the tracer in the tubular fluid was in the form of urate, indicating that urate is not oxidized when it is transported across the tubular cell. It is concluded from these results that: 1. The rat kidney has no significant uricase activity. 2. Urate transport in the kidney is not influenced by this enzyme. 3. The degradation of urate to allantoin takes place at extrarenal sites, mainly in the liver.
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  • 45
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    Pflügers Archiv 352 (1974), S. 115-120 
    ISSN: 1432-2013
    Keywords: Urate ; Reabsorption ; Loop of Henle ; Micropuncture ; Microperfusion ; Microinjection ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Reabsorption rates for urate in the loops of Henle were measured in superficial nephrons in the rat 1. under conditions of free flow, 2. using microperfusion and 3. by a microinjection technique. 1. Under conditions of free flow distally measured TF/PUA/TF/PIn-values varied between 0.51 and 0.38 in antidiuretic rats, depending on TF/PIn (UA = both uric acid and urate, In = inulin, TF/P = concentration in tubular fluid to plasma concentration). The corresponding values in samples from end-proximal tubules were 1.06 and in urine 0.19 (U/PUA/U/PIn). 2. In microperfusion experiments of Henle loops early distal recoveries of 2-C14 urate varied between 57 and 86%, depending on the flow rates (10–40 nl/min). 3. In microinjection experiments C14 recovery in urine was about 85% when tracer solution was microinjected into endproximal tubules. From these results we conclude: 1. The main site of urate reabsorption is located in the loops of Henle. 2. This reabsorption is highly dependent on flow rates. Increase of flow rate through Henle's loop decreases urate reabsorption.
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  • 46
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    Pflügers Archiv 352 (1974), S. 121-133 
    ISSN: 1432-2013
    Keywords: Urate ; Protein Interaction ; Uptake by Erythrocytes ; Renal Reabsorption ; Man ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Interaction of urate with human and rat plasma was studied by a dialysis technique at different temperatures. At 4° C a certain fraction of urate is bound to proteins. However, this fraction diminishes with increasing temperature and at 37° C only some 7–8% (in man) and 2% (in rat) interact with proteins. The finding that urate is almost completely filtered in the glomerulus is discussed. In body areas exposed to low temperatures protein binding of urate may be of importance. Urate uptake by erythrocytes is characterized by two components: a fast component equilibrating almost immediately at about 7% in man and 17% in rat and a slow component reaching equilibrium after 60 min, at 28% and 36%, respectively. The process is described by a mathematical formula. Lowering of the temperature mainly diminishes uptake by the slow component withQ 10-values ranging between 1.5 and 4.0. In the observed range of concentrations the uptake process does not saturate. The results at lower pH-values suggest that it is unionized uric acid which is transported by the slow component. Application of the data to kidney medulla supports the hypothesis that erythrocytes and, probably, to a lesser extent plasma proteins serve as vehicles for urate reabsorption in the countercurrent system. Such a temporary interaction enables uric acid to escape recirculation and to leave the kidney medulla.
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  • 47
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    Pflügers Archiv 350 (1974), S. 241-248 
    ISSN: 1432-2013
    Keywords: Cardiac Hypertrophy ; Diffusion Distance of Oxygen ; High Altitude ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In rats born and staying their whole life at a simulated altitude of 3500 m a severe cardiac hypertrophy develops which is most pronounced in the right ventricle. On histological sections muscle fiber and capillary densities were counted and the surfaces occupied by muscle fibers and capillaries in the slides were estimated. Mean muscle fiber diameter and half mean distance between capillaries (diffusion distance) were obtained in the heart ventricles and were compared with those of control animals. In both ventricles an increase of the mean muscle fiber diameter occurred (true hypertrophy), being more pronounced in the right ventricle. We cannot tell whether also hyperplasia of muscle fibers occurred or not. The diffusion distance in the left ventricle of rats exposed to hypoxia was about the same as in control animals but was shorter in the right ventricle. This indicates that the total number of capillaries is higher in both ventricles of rats born in the low pressure chamber (hyperplasia of the capillaries). The shortening of the diffusion distance in the right ventricle of rats born and living their whole life at simulated high altitude was on the average smaller than that of rats exposed to simulated high altitude later in life. The physiological importance of this observation is discussed.
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  • 48
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    Pflügers Archiv 351 (1974), S. 13-24 
    ISSN: 1432-2013
    Keywords: Hypothalamus ; Spike-Trains ; Correlogram/Periodogram ; Thermosensitivity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stationary spike-trains of preoptic neurons of the rat were submitted to a correlation- and spectral-analysis at normal temperature and after central warming and cooling. Correlograms and periodograms were computed which enable the elimination of stochastic signal components and the identification of the relevant periodic components. About one half of the analysed neurons showed periodic correlograms. The following three classes may be distinguished: Neurons which showed correlograms with periodicities at each applied thermal state, at only one or two thermal states and those with no recognizable periodicities at all. Relations between periodicity and the thermosensitivity of the neurons are discussed.
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  • 49
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    Journal of neurology 208 (1974), S. 1-16 
    ISSN: 1432-1459
    Keywords: Neuroblastoma, central ; N-methyl-N-nitrosourea ; Transplacentar carcinogenesis ; Neuronal differentiation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die transplacentare Gabe von MNH an schwangere Ratten am 16. Tage der Gravidität, obwohl sie bei allen untersuchten Nachkommen zu Gehirnmißbildungen führte, erzeugte nur einen Tumor des Nervensystems. Dieser bösartige Tumor, bei dem am Lichtmikroskop die Diagnose Neuroblastoma gestellt wurde, wurde auch durch E.M. untersucht. Obwohl Strukturen stark andeutend auf unreife oder regressive synapsenartige Kontakte vorhanden waren, konnten gutentwickelte Synapsen jedoch nicht beobachtet werden. Bei den verschiedenen neuronalen Eigenschaften, die bei den Tumorzellen zum Vorschein kamen, besonders extensive Nissl-Schollen und zahlreiche „subsurface“ Zisternen, waren mehrere typisch für die embryonale Entwicklung der Nervenzellen: geästete Zellfortsätze mit Wachstumskonen und dense core, neurosekretorische Granula; diese Granula wurde als charakteristisch für neuerwachsende Nervenfasern angesehen. Die Anwesenheit dieser Entwicklungsmerkmale in einem Nervenzellenmalignom kann die vermutete embryonale Abstammung des Neuroblastomas als Abkömmling von unreifen Formen und nicht von entdifferenzierten Zellen bestätigen.
    Notes: Summary Transplacentar administration of MNU to pregnant Wistar-R rats at the 16th day of gestation, while inducing cerebral malformations in all the offspring examined, produced only one nervous system tumor. This malignant neoplasm, diagnosed optically as a neuroblastoma, was also examined at the EM level. Although structures strongly suggestive of incipient or abortive synaptic formations were present, well developed synapses were not observed. Among the various neuronal features displayed by the tumor cells, notably some extensive Nissl arrays and numerous subsurface cisternae, several were indicative of maturing nerve cells: branching tumoral processes provided with typical growth cones and dense cored “neurosecretory” vesicles. These vesicles are now considered to be one of the characteristics of newly developing nerve fibers. The presence of these developmental features in a nerve cell tumor helps to substantiate the embryonic origin of neuroblastomas postulated as arising from immature forms and not from dedifferentiated cells.
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  • 50
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    Research in experimental medicine 162 (1974), S. 63-66 
    ISSN: 1433-8580
    Keywords: Rhyolithic pumice ; Ferrihexacyanoferrate (II) ; Thallium ; Rat ; Rhyolithischer Bims ; Ferrihexacyanoferrat (II) ; Thallium ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Orale Verabfolgung von rhyolithischem Bims bewirkt eine herabgesetzte Retention von Thallium in den Geweben. Die Wirksamkeit von Rhyolith zeigt eine ausgeprägte Dosisabhängigkeit, ist aber geringer als die von Ferrihexacyanoferrat (II).
    Notes: Summary Oral administration of rhyolith leads to a diminished retention of thallium by the tissues. The effectiveness of rhyolith markedly depends on its dosage, but is surpassed by that of ferrihexacyanoferrate (II).
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  • 51
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    Research in experimental medicine 162 (1974), S. 313-321 
    ISSN: 1433-8580
    Keywords: Coprophagy ; Rat ; Calcium metabolism ; Bone morphology ; Immobilization ; Koprophagie ; Ratte ; Calciumstoffwechsel ; Knochenmorphologie ; Immobilisierung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Wir untersuchten den Einfluß der Koprophagie auf den Calciumstoffwechsel der Ratte. 20 Versuchstiere wurden durch Einschnüren in einen Lederpanzer an der Koprophagie gehindert und mit 21 Kontrolltieren gleicher Futteraufnahme verglichen. Die Kinetik des Calciumstoffwechsels wurde unter Verwendung von45Ca als Tracer analysiert. Die radiochemischen Resultate wurden mit den histologischen Beobachtungen an den Epi-Metaphysen der Kniegelenke verglichen. Bei den Versuchstieren mit verhinderter Koprophagie fanden wir: 1. ein hochsignifikant niedrigeres Körpergewicht; 2. eine hochsignifikante Verkleinerung folgender Parameter des Calciumstoffwechsels: Compartmentgröße und Austauschrate zwischen ihnen, Calciumausscheidungsraten, Knochenan- und -abbau; 3. eine Verschmälerung der Wachstumsfuge, verkürzte und verschmälerte primäre Knochenbälkchen, verminderte sekundäre metaphysäre Spongiosa. Bei 4 Versuchstieren, die in Lederpanzern gehalten, denen jedoch die Koprophagie ermöglicht war, wurden gleichartige histologische Veränderungen wie bei verhinderter Koprophagie festgestellt. Es wird gefolgert, daß die Verhinderung der Koprophagie keinen meßbaren Einfluß auf die Parameter des Calciumstoffwechsels hat.
    Notes: Summary We investigated the influence of coprophagy on the calcium metabolism of the rat. 20 experimental animals were prevented from coprophagy by wrapping them in leather harnesses and compared with 21 controls on the same food intake. Kinetics of calcium metabolism were analysed using45Ca as tracer. The radiochemical results were compared with the histological observations in the epi-metaphyses of the knee joints. In the experimental animals prevented from coprophagy we found: 1. a highly significant lower body weight; 2. a highly significant diminution of the following parameters of calcium metabolism: compartment sizes and exchange rate between them, calcium excretion rates, bone accretion and resorption; 3. a narrower epiphyseal growth cartilage, clearly shorter and narrower primary trabeculae, rarefied secondary metaphyseal trabeculae. Histological alterations identical to those observed with coprophagy prevented, were found in 4 animals kept in harnesses but with coprophagy allowed. It is concluded that prevention of coprophagy has no measurable influence on the parameters of calcium metabolism.
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  • 52
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    Research in experimental medicine 163 (1974), S. 39-45 
    ISSN: 1433-8580
    Keywords: D-penicillamine ; Acetazolamide ; Renal excretion ; Rat ; D-Penicillamin ; Acetazolamid ; Renale Exkretion ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die renale Ausscheidung von D-Penicillamin läßt sich weder durch Probenecid noch durch N-Methylnicotinamid oder NH4Cl beeinflussen. Acetazolamid bewirkt eine erhöhte Retention von D-Penicillamin in Haut und Muskulatur und hemmt dessen renale Ausscheidung, hat jedoch keinen Effekt auf die Dekorporationswirksamkeit von D-Penicillamin bei60Co. Die möglichen Ursachen des Einflusses von Acetazolamid auf die Verteilung und Exkretion von D-Penicillamin werden diskutiert.
    Notes: Summary The renal excretion of D-penicillamine is not influenced by probenecid, N-methylnicotinamide, and NH4Cl. Acetazolamide brings about an increased retention of D-penicillamine in skin and muscles and lowers its urinary excretion, but does not exhibit any influence on the efficacy of D-penicillamine in removing internally deposited60Co. The possible causes for the action of acetazolamide on the distribution and excretion of D-penicillamine are discussed.
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  • 53
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    International archives of occupational and environmental health 32 (1974), S. 129-144 
    ISSN: 1432-1246
    Keywords: Lead intoxication ; Lead line ; Electron microscopy ; Stomato-Logy ; Bleiintoxikation ; Bleisaum ; Elektronenmikroskopie ; Stomatologie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die histologischen Befunde beim Bleisaum im Licht- und Dunkelfeld werden kurz besprochen. Die Beobachtungen stimmen mit den bekannten Angaben aus der Literatur überein. Elektronenmikroskopische Untersuchungen an Gingivabiopsien von 3 Patienten mit Bleivergiftung und deutlichem Bleisaum zeigten, daß die Ablagerungen sowohl extra- als auch intracellulär zu finden sind. Extracelluläres Blei war hauptsächlich zwischen kollagenen Pasern, um die Blutgefäße und in die Basallamina an der dermo-epidermalen Grenze eingelagert. Intracelluläres Blei war in einer Gruppe von Zellen in membranbegrenzten Phagosomen vorhanden, während es in anderen Zellen diffus im Cytoplasma verteilt war, wobei es zu einer Einlagerung in die verschiedenen cytoplasmatischen Membransysteme, besonders in die mitochondrialen Membranen, kam. Reste von lytischen Zellen mit diffus im Cytoplasma verteiltem Metall wurden von Makrophagen aufgenommen. Es wird vermutet, daß ein Cyclus abläuft, der mit der Phagocytose von Blei beginnt und über progrediente Zellschädigung zur Lyse führt. Die Ergebnisse werden mit Beobachtungen bei Argyrose verglichen. Das unterschiedliche Verteilungsmuster der Metalle bei diesen beiden Erkrankungen wird im Hinblick auf eine Hypothese über den Pathomechanismus von Schwermetallvergiftungen diskutiert.
    Notes: Summary The histology of the lead line is briefly reviewed on the basis of light- and dark-field microscope studies. The observations correspond with published data. Electron microscope studies on gingival biopsies obtained from 3 patients with lead intoxication and marked lead lines showed extra- and intracellular deposits of the metal. Extracellular lead was preferentially deposited between collagen fibers, around blood vessels and on the basal lamina of the dermal-epidermal junction. Intracellular lead was present within membrane-bound phagosomes of one group of cells, whereas it was diffusely distributed within the cytoplasm of another cell group. In the latter it was deposited on the different cytoplasmic membrane systems, particularly on the mitochondrial membranes. Residues of lytic cells, which contained diffusely distributed metal, were phagocytized by macrophages. It is assumed that a cycle starts with the phagocytosis of lead and ends with increasing cellular damage and cytolysis. The results are compared with the observations in argyria. The different distribution patterns of the metal in the two diseases are discussed in the light of a proposed hypothesis on the pathomechanisms of heavy-metal poisoning.
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  • 54
    ISSN: 1573-0832
    Keywords: Microsporon audouinii ; Pyrrolnitrin ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Scanning and transmission electron microscopy showed that a ceiling quantity (1.56 mcg) of antifungal antibiotic Pyrrolnitrin caused heavy damage to dermathophyteMicrosporon audouinii Gruby CBS 313-54in vitro. Suitable preparation technique made it clear that the changes involved consisted of hyphal collapse on the edge of the culture, with loss of euplasmic organelles identity and cell autolysis. The cell wall, however, was apparently undamaged. These findings fit in with the suggestion that the mode of action of the antibiotic leads to generalised lipoproteic membranes damage. They must, however, be considered as representing the result of the terminal phase of cell distress.
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  • 55
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    Langenbeck's archives of surgery 336 (1974), S. 15-23 
    ISSN: 1435-2451
    Keywords: Rat ; Splenectomy ; Gastric Ulceration ; Increase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An Ratten wurde der Einfluß von Splenektomie auf Magensaftsekretion und Ulcusentstehung untersucht. Sowohl nach “restraint-stress” als auch Pylorusligatur wiesen die splenektomierten Tiere eine ausgeprägte Steigerung der Ulcuszahl und -größe gegenüber den Kontrolltieren auf. In der Magensaftanalyse waren dagegen die Werte der splenektomierten Tiere gegenüber den scheinoperierten nur geringgradig gesteigert. — Als mögliche Ursache der vermehrten Ulcusanfälligkeit nach Splenektomie wurde eine Veränderung lokaler, nicht säuresekretorischer Faktoren der Magenwand diskutiert.
    Notes: Summary In Splenectomiced rats incidence of gastric ulceration was compaired with control groups. Restraint stress and ligation of pylorus was used as model. Splenectomiced rats do show an higher incidence in both models. Both frequency and extension of gastric ulcer were accumulated significantly. Analysis of gastric secretion was only unessentially raised in comparisom to control-groups. Change of protective factors of stomach as possible reason is discussed.
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  • 56
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    Research in experimental medicine 163 (1974), S. 289-298 
    ISSN: 1433-8580
    Keywords: Gastrinpentapeptide ; Vagotomy ; Acid secretion ; Perfusion test ; Rat ; Gastrinpentapeptid ; Vagotomie ; Säuresekretion ; Perfusionsversuch ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei männlichen Wistarratten wurde eine trunkuläre beiderseitige Vagotomie — ergänzt durch eine Pyloroplastik — angelegt. 4 Wochen später erfolgte in Urethannarkose eine Perfusion des Magens mit 0,9%iger NaCl-Lösung in Anlehnung an die Versuchsanordnung von Ghosh. Die Vollständigkeit der Vagotomie bestätigte ein Hypoglykämietest. Im Abstand von 150 min erhielten die Tiere — in 6 Gruppen zu je 10 Ratten — 2 × 50, 100, 150, 200, 250 oder 300 µg/kg KG Pentagastrin subcutan. Die statistisch ausgewerteten Ergebnisse lassen sich wie folgt zusammenfassen: 1. Die nach dem Abklingen der Wirkung der ersten Pentagastrininjektion wiederholte Pentagastringabe in derselben Dosis ergab bei allen Dosierungen eine höhere Säuresekretion als nach der ersten Injektion. 2. Ein Maximum der sezernierten Säuremenge wurde bei einer Dosis von 100 µg/kg KG erreicht. Bei höherer Dosierung des Pentagastrins nahm die Menge der sezernierten Säure signifikant ab.
    Notes: Summary Male Wistar rats were subjected to a complete bilateral vagotomy and a pyloroplasty. 4 weeks later followed in urethane anesthesia a continuous perfusion of the stomach with 0.9% saline according to the rat preparation of Ghosh. The completeness of the gastric vagotomy was confirmed by a postoperative insulin test. In an interval of 150 min the rats — in 6 groups of 10 rats each — were two times injected pentagastrin subcutaneously in dose rates of 50, 100, 150, 250 or 300 µg/kg body weight. The statistical confirmed results can be summarized as followed: 1. The second injection of pentagastrin — 150 min after the first — in the same dose produced a significantly higher gastric acid secretion in the rat all dose rates in comparison to the first injection. 2. The maximal gastric acid secretion was produced by a dose rate of 100 µg/kg body weight of pentagastrin. At higher dose rates of pentagastrin there was a significant reduction of gastric acid secretion.
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  • 57
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    Research in experimental medicine 164 (1974), S. 19-33 
    ISSN: 1433-8580
    Keywords: Kidney ; Rat ; Ultrastructure ; Proximal tubule degeneration ; Heparinoid ; Niere ; Ratte ; Ultrastruktur ; Proximale Tubulusdegeneration ; Heparinoid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 24 Std nach i.v. Injektion von 100 mg/kg eines Pentosanschwefelsäureesters (SP 54) sind in der Nierenrinde von Ratten schwere degenerative Veränderungen der proximalen Tubuluszellen zu beobachten. Das Tubulusepithel ist flachkubisch umgewandelt, das Tubuluslumen ist angefüllt mit ausgestoßenen Mitochondrien und anderen Zelltrümmern. Am stärksten betroffen ist die Pars contorta des proximalen Tubulus. Weniger stark veränderte Tubuluszellen sind angefüllt mit Cytosomen, die eine spezifische Feinstruktur haben oder gehäuft gegenüber Kontrollen Cytoplasmaprotrusionen in das Tubuluslumen aufweisen. Die akute Tubulusdegeneration ist ein spezifischer Effekt von SP 54. Heparin bewirkt nur eine leichte Schwellung des Tubulusepithels, die häufiger auftritt als bei Kontrolltieren.
    Notes: Summary 24 hrs after the intravenous injection of 100 mg/kg of a Pentosansulfuricacidester (SP 54) severe degenerative alterations are observed in the proximal tubular cells in rat kidney cortex. The tubular epithelium has changed to a single layer of elongated cubic cells. The tubular lumen is filled with cellular debris and extruded mitochondria. The greatest change is seen in the pars contorta of the proximal tubule. Less degenerated tubular cells have a great number of cytosomes with a specific substructure or have cytoplasmatic protrusions into the tubular lumen. This acute tubular degeneration is a specific event after the administration of SP 54 and is not seen after an equimolar dosis of Heparin. Heparin induces only a slight swelling of the tubular epithelium, more frequent seen as in the control animals.
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  • 58
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    Research in experimental medicine 163 (1974), S. 341-349 
    ISSN: 1433-8580
    Keywords: Experimental uremic syndrome ; Rat ; 5/6 reduction of renal parenchyma ; Serum- and urine analysis ; Secondary hyperparathyroidism ; Experimentelles urämisches Syndrom ; Ratte ; 5/6-Reduktion des Nierenparenchyms ; Serum- und Urinanalyse ; Sekundärer Hyperparathyreoidismus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Durch eine 5/6-Nierenparenchymreduktion wurde an Ratten ein chronisches, durch bilaterale Nephrektomie ein akutes urämisches Syndrom erzeugt. Beim chronischen urämischen Syndrom erwiesen sich in der Serumanalyse die Konzentrationen des Harnstoffstickstoffs und des Kreatinins als wesentlich erhöht. Darüber hinaus bestanden alle chemischen Zeichen eines sekundären Hyperparathyreoidismus. Die Tiere litten außerdem an einer schweren Poly-, Protein- und Albuminurie. Überraschenderweise war aber der Spiegel des totalen Serumproteins gegenüber den Kontrolltieren erhöht. Das experimentelle chronische urämische Syndrom stellt eine extreme Adaptation der regulatorischen Aktivität des Nierenrestparenchyms und des ganzen Organismus dar. Beim akuten, durch bilaterale Nephrektomie erzeugten urämischen Syndrom besteht dagegen ein schweres Versagen der Regulation des Wasser- und Elektrolytstoffwechsels, welches innert 50–60 Std zum Tode der Versuchstiere führt.
    Notes: Summary A chronic uremic syndrome was induced by 5/6 nephrectomy and an acute uremic syndrome by bilateral nephrectomy in rats. In the chronic uremic syndrome serum and urine analysis revealed a highly increased serum level of BUN and creatinine. Furthermore, all chemical signs typical of secondary hyperparathyroidism were present. The animals suffered from severe polyuria, protein- and albuminuria but, surprisingly, the total serum protein was increased. The experimental chronic uremic syndrome is, in essence, a syndrome of “extreme adaptation” of the regulatory activity of remnant renal parenchyma and of the whole body. In contrast, the acute uremic syndrome induced by bilateral nephrectomy is a severe disorder of water and electrolyte metabolism resulting in death of the experimental animals after 50–60 hrs.
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  • 59
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    Cell & tissue research 147 (1974), S. 157-161 
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Iris ; Lanthanum nitrate ; Sarcoplasmic reticulum ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Smooth muscle cells of the guinea-pig sphincter pupillae were fixed in the presence of 3% lanthanum nitrate. Although only small amounts of lanthanum were found in plasmalemmal vesicles, large deposits were present within a membrane system resembling sarcoplasmic reticulum. The significance of these findings is discussed in relation to the use of lanthanum nitrate as an extracellular tracer.
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  • 60
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    Cell & tissue research 147 (1974), S. 183-190 
    ISSN: 1432-0878
    Keywords: Kidney ; Rat ; Bowman's capsule ; Experimental hypertension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The parietal layer of Bowman's capsule was examined in the rat in control animals and in animals made hypertensive by treatment with desoxycorticosterone acetatesaline and by clipping of the renal artery. At an early stage of elevation of blood pressure and, occasionally, prior to elevation of blood pressure, the epithelial cells of this layer showed basal cytoplasmic protrusion and reduplication accompanied by an increase in the thickness of the basement membrane. These changes preceded evidence of glomerular or renal arteriolar pathology. They presumably reflect either a response of this layer to increased blood pressure and modified glomerular function, or a direct effect of the factors that also induces blood pressure elevation. In either case, they imply a greater functional significance for the parietal layer than has usually been attributed to it.
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  • 61
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    Cell & tissue research 147 (1974), S. 271-283 
    ISSN: 1432-0878
    Keywords: Intestinum ; Diseases of the colon ; Laboratory animals ; Ruthenium red ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Ruthenium-Rot gefärbte Darmpräparate verschiedener Krankheitsbilder sowie verschiedener Laboratoriumstiere wurden elektronenmikroskopisch untersucht. Ruthenium-Rot läßt sich im Bereich des Intestinaltraktes teils homogen, teils grob- und feingranulär nachweisen. Microvilli and Glycokalyx sind relativ konstant Ruthenium-Rot gefärbt. Der Intercellularraum der Lamina epithelialis mucosae zeigt eine auffallend variable Ruthenium-Rot Anfärbung. Diese ist offenbar nicht methodisch bedingt, sondern Ausdruck eines unterschiedlichen bzw. variablen Funktionszustandes. Es bleibt offen, ob Ruthenium-Rot im Sinne einer histochemischen Reaktion bestimmte, im interzellulären Raum gelegene Substanzen markiert, oder als Tracer für den Stofftransport angesehen werden muß. Becherzellen und nekrobiotische Zellen weisen in der Regel eine konstante Ruthenium-Rot Anfärbung auf. Im Stratum proprium mucosae ist der Reaktionsausfall für Ruthenium-Rot sehr inkonstant, möglicherweise auf Grund des langen Penetrationsweges. Ziemlich regelmäßig findet sich allerdings eine Ruthenium-Rot Markierung de Phagolysosomen von Makrophagen. Prinzipielle Unterschiede der explorierten Gewebe und Tierarten bezüglich der Affinität zu Ruthenium-Rot bestehen nicht.
    Notes: Summary Biopsy specimens of human intestines in various disease states and from laboratory animal intestines have been stained with ruthenium red and inspected by electron microscopy. Ruthenium red reaction product is found as a homogeneous deposit and also in the form of coarse and fine granules. Microvilli and the glycocalyx are stained relatively constant by ruthenium red. The intercellular space of the epithelium shows a strikingly variable ruthenium red staining. This variation is apparently not related to the method but indicates differences or variations in the functional state of the membranes. It remains an open question whether the ruthenium red reaction is a histochemical reaction, marking certain substances present in in the intercellular area or whether it should be considered as a tracer for the transport of materials. Goblet cells and necrobiotic cells usually show a constant ruthenium red staining. In the lamina propria the reaction product is very inconstant, possibly on account of the long penetration path from the lumen. The phagolysosomes of macrophages are marked by ruthenium red rather regularly. No fundamental, but only quantitative differences have been found between the various kinds of tissue studied.
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  • 62
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    Cell & tissue research 147 (1974), S. 595-597 
    ISSN: 1432-0878
    Keywords: Mesothelium (rat) ; Surface film ; Ruthenium red ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A surface film with a thickness of 280–570 Å covers the mesothelium of serous membranes in the rat. This film can be stained with ruthenium red. Its considerable water-binding capacity produces the reflecting surface of the serous membranes. The friction of the organs is thereby greatly reduced. Only a small amount of serous fluid must be produced to keep the surface moist. The glucosamino glycans of the surface film are probably synthesized by the mesothelial cells.
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  • 63
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    Cell & tissue research 148 (1974), S. 1-9 
    ISSN: 1432-0878
    Keywords: Branchiostoma ; Osmoregulation ; Cyrtocytes ; Podocytes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The excretory organs of Amphioxus occur as segmentally arranged structures throughout the pharyngeal region and may be divided into three components: the solenocytes, the renal tubule, and the renal glomerulus. The solenocytes possess foot processes that rest upon the coelomic surface of the ligamentum denticulatum. The tubular apparatus of the solenocytes consists of ten triangular rods surrounding a central flagellum. The distal end of the tubular apparatus enters branches of the renal tubule. The renal tubule eventually opens into the atrial cavity of Amphioxus. The renal glomerulus is a sinus within the connective tissue of the ligamentum dentieculatum where it connects elements of the branchial circulation with the dorsal aorta. The renal glomerulus, like other blood vessels of Amphioxus, lacks an endothelial lining. If Amphioxus is adapted to artificial sea water at different concentrations there is no change in kidney morphology suggesting that Amphioxus is either is osmotic with its environment or is osmoregulating with other organs.
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  • 64
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    Cell & tissue research 149 (1974), S. 235-243 
    ISSN: 1432-0878
    Keywords: Adrenal zona glomerulosa ; Rat ; Normal ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This paper reports on an electron microscopic study of the adrenal zona glomerulosa in the normal rat, with special emphasis on the structural diversity of mitochondria in its parenchymatous cells. The mitochondria of cristae may be tubulo-vesicular, plate-like and/or straight tubular, any one mitochondrion containing one or more types of cristae. The mitochondrial features of the zona glomerulosa parenchymatous cells are attributed to the biochemical stages of aldosterone synthesis, taking place in different mitochondria of these cells.
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  • 65
    ISSN: 1432-0878
    Keywords: LRF ; Hypothalamic localization ; Rat ; Ependyma ; Glia ; Light and electron microscopic Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light and electron microscopic autoradiographic analysis of the medial basal hypothalamus of rat brains incubated for 30 and 60 minutes in tritiated luteinizing releasing factor (3H-LRF) revealed selective uptake in the form of silver grains over specialized ependyma (tanycytes) and perivascular glial cells in the palisade-contact zone of the median eminence. The functional capacity of tanycytes and glia are discussed in light of these data.
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  • 66
    ISSN: 1432-0878
    Keywords: Structural water ; Fibrinogen-Fibrinmolecule ; Molecular morphology ; Electron microscopy ; Heat drying
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Standardgerinnsel aus Rinderfibrin wurden in der Kammer einer Versuchsanordnung einem mit Wasser nahezu gesättigten Luftstrom ausgesetzt. Die Gerinnsel kollabierten, und ihr Restwasser wurde in Zeitabständen durch Hitzetrocknung bei 105°C bestimmt. Es resultierte eine zeitabhängige Kurve, die aus 3 Phasen besteht. Elektronen-mikroskopische Aufnahmen zeigen, daß infolge eines Verlustes des freien Wassers während der ersten Phase das Pibringerüst des Gerinnsels kollabiert. Während der dritten Phase kollabiert das Proteingerüst der Fibrinmoleküle infolge des Verlustes von Strukturwasser. Während der zweiten Phase besteht das Gerinnsel aus raumfüllend gepackten Fibrinmolekülen. Das Strukturwasser beträgt dann etwa 5,25 g/g Trockengewicht; die Höhe ist etwa 180 μm und ergibt den wahrscheinlichsten Wert des Strukturwassers, 6,25 g/g Protein. Wenn dieser experimentelle Wert mit entsprechenden, theoretisch zu erwartenden Werten verglichen wird, die von elektronenmikroskopischen Molekularmodellen für Fibrin hergeleitet wurden, so ergibt das Gerinnsel, das aus raumfüllend gepackten Pentagondodekaeder-Modellen besteht, mit etwa 8 g Strukturwasser/g Fibrin die beste Näherung an den im Experiment erhaltenen Wert. Dieses Modell kann — im Gegensatz zu anderen Modellen — Massen-, Volumens- und Morphologieverhältnisse des Gerinnsels und des Moleküls erklären. Die verbleibende Differenz zwischen wahrscheinlichstem experimentellem und theoretischem Strukturwasser-Gehalt ist leicht durch experimentelle Ungenauigkeiten und Anwesenheit von Nicht-Fibrin im Molekularvolumen erklärbar. Mit an Sicherheit grenzender Wahrscheinlichkeit repräsentiert deshalb das Pentagondodekaeder-Modell die Allgemeinstruktur des Fibrin- und Fibrinogenmoleküls.
    Notes: Summary Standard clots of bovine fibrin collapsed in the highly humid air stream of a laboratory device. Their residual water, determined by heat drying at 105°C, resulted in a time dependent curve composed of 3 distinct phases. Electron micrographs show that during the first phase free water is released causing a collapse of the fibrous framework of the clot, during the third phase structural water is lost causing a breakdown of the molecular protein. The clot of the second phase consists of space fillingly packed fibrin molecules, whose directly determined structural water is approximately 5.25 g/g dry wt., but whose height (approximately 180 μm) results in the most probable value 6.25 g structural water/g protein. If this amount is compared with respective theoretical values of electron microscopic molecular models of fibrin, the clot consisting of space fillingly packed pentagon dodecahedron models yields approximately 8 g structural water/g fibrin, closely to the experimental value. In contrast to other models, this model explains simultaneously the shape of the curve, mass and volume relationships and morphology of clot and molecule. The remainding difference between the most probable experimental and this theoretical value can easily be attributed to experimental errors and impurities contained in the volume of the molecule. Consequently, the general structure of the fibrinogen and fibrin molecule is represented by the pentagon dodecahedron model.
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    Cell & tissue research 149 (1974), S. 481-495 
    ISSN: 1432-0878
    Keywords: Brain ; Monoamines ; Amphibia ; Fluorescence microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of monoamines in the brain of Bufo poweri was investigated with the Falck-Hillarp method. Green fluorescence was observed in neurons of the diencephalic preoptic recess organ (PRO) and its so-called additional cells, in the paraventricular organ (PVO) and its so-called accompanying cells, in the nucleus infundibularis dorsalis (NID) and in the mesencephalic nucleus reticularis mesencephali (NRM). Yellow fluorescence was found in some cells of the PVO and NID and in neurons of the caudal part of the NRM. Extensive tracts of aminergic fibres are described running caudo-rostrally and mainly terminating in the septa and striata of the telencephalon. It is suggested that the aminergic nuclei mentioned above partly contribute to the ascending tracts. Other fibres, originating in the PVO and NID are curving centro-caudally towards the median eminence. Although with the electron microscope some apparently aminergic nerve fibres were detected in the pars intermedia, such fibres have not been observed fluorescence microscopically. The ultrastructural study of the PRO has shown the presence of two types of aminergic liquor-contacting neurons. Among the distal cells of the PRO, aminergic and peptidergic neurons were distinguished. The presence of PRO additional cells, which are considered as a rostral extension of the PRO, is discussed with regard to the terrestrial habitat of the species.
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  • 68
    ISSN: 1432-0878
    Keywords: Sea anemone mesoglea ; Collagen synthesis ; Epitheliomuscular cells ; Electron microscopy ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy and autoradiography (H3-proline) were used to determine the cell(s) responsible for collagen synthesis and lamination in the mesoglea of the sea anemone, Aiptasia diaphana. Mesogleal collagen is synthesized by the epidermal epitheliomuscular cells which contain much rough endoplasmic reticulum, and secretory vesicles attached to microtubules which cross the basal plasmalemma and anchor in the basement membrane; these cells incorporate large amounts of H3-proline. The mesogleal collagen fibers are non-striated, have clear centers, and a diameter of 200–260 Å; their walls are composed of 65 Å diameter subunit fibrils which appear to be helically oriented. Epitheliomuscular cells rest upon a subepidermal basement membrane which is composed of mesogleal collagen fibers, 65 Å subunit fibrils, and dense granules. This subepidermal basement membrane labels definitively with H3-proline, and is the region where soluble collagen precursors apparently form subunit fibrils which associate to yield mesogleal fibers. The columnar mesogleal collagen fibers are arranged to form layers: the fibers of each layer have the same longitudinal orientation, while those of adjacent layers display an approximate orthogonal arrangement. It is felt that the subepidermal basement membrane is responsible for this organization of mesogleal fibers. Mesogleal amoebocytes do not label with H3-proline and show no ultrastructural evidence of collagen secretion.
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  • 69
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    Cell & tissue research 150 (1974), S. 43-56 
    ISSN: 1432-0878
    Keywords: Purkinje fibres ; Avian heart ; Fine structure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The subendocardial Purkinje fibres in the right atrium of the heart of the adult fowl were investigated by light and electron microscopy. The myofibrils often originate from the lateral cell membrane of the cells and show a spirally wound course. Their arrangement is obviously not random. In some Purkinje cells the absolute amount of myofibrils per cell is as large as in ordinary myocardial muscle cells. The sarcoplasmic reticulum is constituted by ramifying tubules. They are distributed throughout the entire Purkinje cell and contact the myofibrils, the mitochondria, and the cell membrane. At the cell membrane the sarcoplasmic reticulum forms terminal cisternae, which often possess an electron dense content. These terminal cisternae are apparently unrelated to the Z-discs of the myofibrils. The cytoplasmic organelles of the Purkinje cell are embedded in a network of ca. 100 Å thick filaments. It is assumed that these filaments are responsible for the maintenance of the arrangement of the cell organelles. Some Z-discs of the myofibrils of the Purkinje cells are up to 0.4 μm long. Axon terminals running between the Purkinje fibre and the fibrocytic envelope may lie only 150 Å from the fibrocytes. The fibrocytes are connected by tight junctions and desmosomes and contain fine filaments and microtubules. The possible implications of these findings are discussed.
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  • 70
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    Cell & tissue research 150 (1974), S. 113-123 
    ISSN: 1432-0878
    Keywords: Binucleation ; Amitotic nuclear division ; Palatal epithelium (Guinea pig) ; Keratinocytes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The palatal epithelium of adult male guinea pigs contains a considerable number of binucleate epithelial cells in all strata but the basal cell layer. Electron microscopical examination shows that the two equal-sized nuclei are dome-shaped with the flattened surfaces closely approximated, the distance between the nuclei being 30 nm or more. No points of contact have been found between the nuclear membranes. No differences in number, distribution or ultrastructure of cytoplasmic organelles were found between mono- and binucleate epithelial cells. Evidence of amitotic nuclear division being a plausible mechanism of binucleation is presented.
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  • 71
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    Cell & tissue research 150 (1974), S. 377-387 
    ISSN: 1432-0878
    Keywords: Sarcolemma ; Collagen texture ; Frog ; Electron microscopy ; Replica technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Single stage carbon replicas were obtained from dried bundles of frog skeletal muscle fibres at different sarcomere lengths. In unfixed specimens finer details are masked by an amorphous substance; after fixation with glutaraldehyde a network of collagen fibrils covering the muscle fibres appears. At a sarcomere length of 1.8 μm the collagen fibrils are oriented diagonally and transversely; between a sarcomere length of 2.8 and 3.1 μm the collagen fibrils are increasingly oriented along the axis of the muscle fibre. This indicates a helical arrangement of the collagen fibrils in the sarcolemma, the pitch being grossly related to sarcomere length. Collagen fibrils and fibres in the endomysium are not oriented according to sarcomere length; hence at low degrees of stretch, force applied to the tendon is primarily transmitted by the muscle fibres and not by the endomysium. Replicas from skinned fibres showed that shrinkage is most pronounced in the I-bands and least in the Z-and M-lines.
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  • 72
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    Cell & tissue research 151 (1974), S. 385-394 
    ISSN: 1432-0878
    Keywords: Membrane particles ; Cockroach hemocytes ; Freeze-fracture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Freeze-fracture studies were conducted on the membranes of normal cockroach hemocytes. The plasmalemma is asymmetric with the A fracture face containing 80–100 Å membrane intercalated particles at a concentration of ∼2500/μ2. The B fracture face contains 120–150 Å particles with a relatively low density (∼800/μ2). The nuclear envelope displays an asymmetry with the A fracture face containing ∼1500 particles/μ2 and the B face containing ∼300/μ 2. No significant particle size differences were observed in nuclear envelope fracture faces. Two types of symmetric membranes were also found in these cells. Both A and B fracture faces of the membrane surrounding the numerous cytoplasmic inclusion bodies contain particle sizes and concentrations similar to the B face of the plasmalemma. A second type of symmetry was observed in cells apparently engaged in “exocytosis”. Vesicles (∼0.1 μD) from this process were completely particle free on both fracture faces. Such particle free vesicles could be found in the cytoplasm, attached to the plasmalemma, or completely separated from the cell.
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  • 73
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    Cell & tissue research 151 (1974), S. 457-469 
    ISSN: 1432-0878
    Keywords: Juxtaglomerular apparatus ; Rat ; Adrenalectomy ; Renin and secretory granules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Reaktion des juxtaglomerulären Apparates auf Adrenalektomie wurde untersucht. Im Stadium der Nebenniereninsuffizienz, sechs Tage nach der Operation, wurde quantitativ morphometrisch eine Abnahme der Volumendichte der Sekretgranula (von 32% auf 16%) festgestellt. Golgi-Apparat und Ergastoplasma proliferieren stark, wobei insbesondere die erweiterten Cisternen des Ergastoplasmas auffallen.
    Notes: Summary The response of the Juxtaglomerular apparatus to bilateral adrenalectomy was studied in rats. After the sixth postoperative day, symptoms of severe adrenal insufficiency had developed. In the Juxtaglomerular cells, the volume density of the secretory granules decreased from 32% to 16%. The Golgi apparatus and rough endoplasmic reticulum underwent considerable proliferation, the latter showing strikingly enlarged cisternae.
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  • 74
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    Cell & tissue research 151 (1974), S. 433-456 
    ISSN: 1432-0878
    Keywords: Juxtaglomerular apparatus (Rat) ; Development ; Renin ; Pools ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die perinatale Entwicklung des juxtaglomerulären Apparates, insbesondere das Verhalten der epitheloiden Zellen wurde an 18 trächtigen Ratten and 65 Embryonen bzw. Jungtieren elektronenmikroskopisch untersucht. Parallel dazu wurde die Reninkonzentration bzw. der Reningehalt bestimmt. Spezifische Sekretgranula finden sich erstmals am 18. Tag der Fetalzeit, und zwar in den epitheloiden Zellen des juxtaglomerulären Apparates juxtamedullärer Nephrone. Die Granula machen einen Struktur- und wahrscheinlich auch Funktionswandel durch, der eine Einteilung in drei verschiedene Granulatypen nahelegt. Diesen drei Typen spezifischer (reninhaltiger) Sekretgranula werden die Lysosomen als unspezifische Einschlüsse der epitheloiden Zellen gegenübergestellt. Im einzelnen kommt es während der perinatalen Phase in den fetalen Epitheloidzellen zuerst, d.h. pränatal, zu einer Hypertrophie des rauhwandigen endoplasmatischen Retikulums und des Golgi-Apparates. Hierin sehen die Autoren einen Hinweis auf eine erhöhte Proteinsynthese mit entsprechender Zunahme der Transport- und Konzentrationsvorgänge. Nach der Geburt findet sich dann auch eine deutliche Zunahme der Sekretgranula vom Typ III, die als reife Reningranula (mature granules) angesehen werden. Die bisher noch nicht beschriebenen kleinen Sekretgranula vom Typ I dagegen kommen in weniger entwickelten Epitheloidzellen häufiger vor. Bestimmungen der Reninverteilung zwischen Zytoplasma und den durch Differential-zentrifugation gewonnenen Granula-Fraktionen ergeben auffallende Parallelen zu den morphologischen Befunden. Diese sprechen im allgemeinen dafür, daß “freies Renin” im Ergasto-plasma und “gebundenes Renin” in den Sekretgranula vorliegt. Mit zunehmendem Alter scheint es außerdem — parallel zur relativen Abnahme des Ergastoplasmas und Zunahme der reifen Reningranula — zu einer Verminderung des extragranulären zugunsten des granulär gebundenen Renins zu kommen.
    Notes: Summary The perinatal development of the Juxtaglomerular apparatus (JGA), with particular reference to the epithelioid cells, was studied. Electron microscopic studies were carried out on 18 gravid rats and 65 embryos with corresponding determinations of renin concentration and the renin contents by bio-assay. Specific secretory granules of the epithelioid cells of the JGA of juxtamedullary nephrons are first observed on the 18th day of gestation. The classification into three types of secretory granules suggests that they undergo a structural and probably also a functional transformation. All three types of secretory granule may be regarded as specific, renin-containing, cytoplasmic organelles. During the last days of gestation, the rough-surfaced endoplasmic reticulum and the Golgi apparatus become hypertrophied in epithelioid cells, indicating an increased protein synthesis as well as transport and concentration processes. After birth, there is a definite increase in the number of Type III secretory granules-which may be regarded as mature granules. The small Type I secretory granulesnot previously described-are found more frequently in the immature epithelioid cells. Determinations of the renin distribution in the plasma and in fractions of cytoplasmic constituents (total homogenate, secretory granules) prepared by differential centrifugation showed striking congruence with the morphological findings. It is generally assumed that “soluble renin” occurs in the endoplasmic reticulum and “bound renin” in secretory granules. A shift from extragranular to granular (bound) renin, occurs with increasing age, having its morphological equivalent in the relative decrease of the endoplasmic reticulum and increase in mature secretory granules.
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  • 75
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    Cell & tissue research 152 (1974), S. 13-30 
    ISSN: 1432-0878
    Keywords: Human fetal pineal gland ; Development ; Secretion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the pineal gland of 18 human fetuses (crown-rump lengths 30–178 mm) was investigated. The pineal gland exhibits a pyramidal shape and consists of an anterior and posterior lobe. Only one parenchymal cell type, the pinealocyte, was observed. Few neuroblasts were seen between the pinealocytes and in the extended perivascular space. The pinealocytes possess all the organelles necessary for hormone synthesis. No specific secretory granule could be observed. The organ is abundantly vascularized and richly innervated. The morphology of the capillaries indicates the existence of a blood-brain barrier. The ultrastructure of the human fetal pineal gland suggests that the gland has a secretory function in early intrauterine life.
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  • 76
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    Cell & tissue research 152 (1974), S. 51-67 
    ISSN: 1432-0878
    Keywords: Myelin ; Ventral habenular nuclei ; Interpeduncular nucleus ; Rana esculenta ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An ultrastructural analysis of myelin in the ventral habenular and in the interpeduncular nuclei of the adult frog Rana esculenta has been carried out. In the ventral habenular nuclei, in addition to normally myelinated fibres, some myelin irregularities have been observed. They consist of myelin enwrapping the perikarya of some neurons and of isolated flaps of collapsed myelin. In the interpeduncular nucleus numerous myelinated fibres occur but few redundant myelin irregularities have been noticed. The morphological data suggest that myelination of fibres in these sites is due to the spiral wrapping mechanism from a glial cell process while the myelin irregularities described in the ventral habenular nuclei are probably due to membrane synthesis within the cytoplasm of the myelinated neurons and of the oligodendrocytes which are sometimes observed in contact with the ensheathed neurons. In the interpeduncular nucleus myelinated fibres indenting astrocytes and oligodendrocytes have been observed.
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  • 77
    ISSN: 1432-0878
    Keywords: Aedes aegypti ; Midgut epithelium ; Cytology ; Morphometry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Ultrastruktur des Mitteldarmes von Aedes aegypti Weibchen wurde morphometrisch untersucht. Besonderes Interesse lag dabei auf quantitativen Unterschieden im Bau der Epithelzellen eines vorderen (A) und eines hinteren (P) Abschnittes des Mitteldarmes, um jedem dieser beiden Abschnitte bestimmte Funktionen zuordnen zu können. 5 physiologisch verschiedene Stadien wurden verglichen: 1 = unreife Weibchen; 2 = zum 1. Blutmahl (B.M.) bereit; 3 = Verdauung des B.M.; 4 = zum 2. B.M. bereit; 5 = alternde Weibchen. Wenn der Mitteldarm noch nicht funktionsbereit ist (Stadium 1) gleichen sich die Epithelzellen von A und P quantitativ ultrastrukturell. In den folgenden Stadien hingegen werden deutliche Unterschiede sichtbar. Das Zellvolumen und die Kern-Cytoplasma-Relation werden in P generell größer als in A. Parallel dazu nehmen der Mitochondriengehalt und die Oberfläche des rauhen endoplasmatischen Retikulums in P gegenüber A zu. In A entwickeln sich mehr Microvilli, ein extensiveres basales Labyrinth und ein deutliches glattes endoplasmatisches Retikulum. Vergrößerte Cytoplasmavolumina vor allem in den P-Zellen werden 24 Std. nach dem 1. B.M. gefunden (Stadium 3). Parallel dazu erreichen die Volumina der Organellen und/oder ihre Membranoberflächen ebenfalls Maximalwerte. Diese Vergrößerung des gesamten Zell-apparates läßt den Schluß zu, daß während der Blutverdauung die Funktionskapazität des Mitteldarmes erhöht ist. Basierend auf den quantitativ ultrastrukturellen Unterschieden zwischen den Zellen von A und P wurde postuliert, daß dem vorderen Abschnitt des Mitteldarms verstärkte Absorptionsfunktionen zukommen. Dem hinteren Abschnitt hingegen wurden gesteigerte Protein-syntheseleistungen im Zusammenhang mit der Bildung von Verdauungsenzymen zugeordnet. Die vorliegenden Resultate wurden an einem, in Beziehung auf seine Ernährung, spezialisierten Insekt gewonnen (Blutverdauung). Trotzdem scheint die postulierte Zuordnung von Funktionen zu bestimmten Mitteldarmzonen mit dem “secretion—absorption”-Modell (Berridge, 1970) übereinzustimmen.
    Notes: Summary The ultrastructure of the midgut of Aedes aegypti females was investigated by means of morphometric techniques. The interest was focussed on quantitative differences in the composition of epithelial cells between the anterior (A) and posterior (P) part of the midgut. The aim was to attribute defined functions to each of these 2 parts. 5 different physiological stages were compared: 1 = immature female; 2 = ready for first blood meal (b.m.); 3 = digestion of b.m.; 4 = ready for 2nd b.m.; 5 = aging female. Whereas in stage 1, when the gut has not yet reached a functional state the epithelial cells of A and P resemble each other, distinct differences develop in subsequent stages. Generally the cell volume and the nuclear-cytoplasmic ratio become higher in P than in A. Concomitantly the mitochondrial content and the surface area of the rough endoplasmic reticulum are more prominent in P than in A. On the other hand more microvilli, a more extensive basal labyrinth and a well developed smooth endoplasmic reticulum are present in A. Enlarged cytoplasmic volumes, especially high in P, are found 24 h after the first b.m. (stage 3). In accordance with this increase the volume of organelles and/or their membrane surface areas also reach maximal values. This augmentation of the metabolic cell apparatus suggests that during blood digestion the whole organ develops an increased functional capacity. From the quantitative structural differences in A and P we concluded that the A-part of the midgut is especially involved in absorption. To the P-part more protein synthesis may be attributed, thus indicating an enhanced formation of digestive enzymes. Although this study deals with a rather specialised insect (blood digestion), it appears that our hypothesis attributing functions to defined midgut zones, agrees to a certain extent with the “secretion-absorption-model” of Berridge (1970).
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  • 78
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    Cell & tissue research 152 (1974), S. 185-191 
    ISSN: 1432-0878
    Keywords: Laryngeal muscles ; Female tree frog, Hyla arborea arborea (L.) ; Fine structure ; Motor endplates ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The larynx musculature of female tree frogs is very poorly developed compared with that of males. This is probably due to the fact that they are less used; female tree frogs do not produce mating calls. The larynx muscles of the female are composed of fibers with small, medium, and large cross-sections. The distribution of the motor end plates varies correspondingly: in regions with fibers of very small diameter the density of synapses is about 33 times greater than in regions with large fibers. There is also a difference in fine structure between male and female laryngeal muscles. The muscles of females comprise red fibers, white fibers, and various transitional types. The arrangement of the triads and their number per sarcomere is the same in all fiber types. All fibers contain about the same amounts of glycogen, but the fat content varies widely among the different types.
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  • 79
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    Cell & tissue research 152 (1974), S. 467-475 
    ISSN: 1432-0878
    Keywords: Sertoli cell ; Human testis ; Nucleolus ; Nuclear bodies ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the nucleus of human Sertoli cells has been studied in testicular samples from normal adults and patients with hypospermatogenesis or absence of the germinal cell line (Sertoli cell only syndrome). In all cases the ultrastructure of the nuclear structures was alike. The nucleus is irregularly shaped and its membrane presents numerous pores. The inner aspect of the nuclear membrane is electron dense due to the presence of a fibrous lamina. The outer aspect presents a concentric arrangement of 50 Å cytoplasmic filaments. The chromatin is rather dispersed. Some perichromatin granules are found occasionally. The nucleolus is characteristic of human Sertoli cells and displays three clear components. In addition, sphaeridia of at least two principal morphological types were found. Their significance in the cell metabolism as well as relationship to either the nucleolus or the nuclear DNA are discussed. The need for further investigation on the functional meaning of the nuclear organelles of human Sertoli cells is stressed.
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  • 80
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    Cell & tissue research 153 (1974), S. 1-14 
    ISSN: 1432-0878
    Keywords: Graafian follicle (Rabbit) ; Granulosa cells ; Ovulation ; Basement mem-brane ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Membrana granulosa in rabbit Graafian follicles was studied at accurately determined times after an ovulatory dose of human chorionic gonadotrophin (HCG). At 4 and 6 hrs after injection of HCG the granulosa cells were slightly dissociated around the whole follicle. So-called abutment nexuses (gap junctions) had decreased and continued to do so up to ovulation. At 8 hrs after HCG, membrana granulosa had thinned out apically and cell dissociation was even more evident in all parts of the follicle. Granulosa cell projections through the basement membrane were found, and, closer to the time of ovulation, more and larger granulosa cell protrusions penetrated the partly fragmented basement membrane. At 8 hrs spherical inclusions in the granulosa cells, corresponding to so-called annular nexuses, were significantly more numerous than before injection of HCG; the relative amount had more than doubled. Later, the number of annular nexuses decreased. The significance of annular nexuses and their variations is discussed. The decrease in the abutment nexuses probably means a decrease in cohesive force between the granulosa cells and facilitates follicle expansion; moreover, the simultaneous changes in the basement membrane, with more or less open channels into the antrum the last few hours before ovulation, presumably, permit rapid follicle growth by influx of fluid as soon as increased distensibility of the follicle wall allows further expansion without increase in pressure.
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    Cell & tissue research 153 (1974), S. 31-44 
    ISSN: 1432-0878
    Keywords: Graafian follicle (Rabbit) ; Ovulation ; Capillaries ; Intercellular junc-tions ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rabbit Graafian follicles are encircled by a capillary network between the theca interna and the avascular membrana granulosa. After injection of an ovulatory dose of human chorionic gonadotrophin (HCG) the theca interna cells showed an increase in the amount of smooth endoplasmic reticulum, lipid droplets and mitochondria with tubular cristae. In addition, considerably more junctions, similar to the abutment nexuses of granulosa cells were found; annular nexuses also appeared. At 4 hours after injection of HCG a prominent oedema was evident in the theca interna layer, particularly in the apical region. Small fenestrations in the endothelium of the blood capillaries increased in amount after HCG injection, and close to the time of ovulation, large gaps or perforations, 1–3 μ in diameter, were found in the thin, distended part of the endothelial cells. The surrounding basement membrane became fragmented and partly lost, so that a seemingly free passage from the capillary lumen to the interstitium was eventually established. Leakage of fluid, causing interstitial oedema, presumably proceeds until the pressure in the pericapillary interstitium has risen to the pressure in the capillaries. Some hours before and up to ovulation the pericapillary interstitium has also broad communications with the cavity of the follicles. Therefore, both pressure and fluid can be passed from the capillaries-via the interstitium-to the follicle antrum. However, influx of fluid with subsequent follicle expansion and ovulation-at constant pressure-does not occur until the tensile strength of the follicle wall has decreased.
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    Cell & tissue research 153 (1974), S. 79-88 
    ISSN: 1432-0878
    Keywords: Yolk nuclei ; Nassarius reticulatus ; Cleavage ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Dotterkerne kommen in allen Blastomeren des 4- bis 16-Zellstadiums von Nassarius vor. Sie haben überwiegend kugelige Gestalt und liegen kernnah zwischen Kern und apikalem Plasmalemm. Feinstrukturell sind sie erstaunlicherweise nicht einheitlich aufgebaut, sondern treten in zwei Typen auf: Typ I besteht aus einer relativ kompakt erscheinenden kugeligen Ansammlung von Mitochondrien. Die Mitochondrien liegen in einer dichten, teils granulären, teils fibrillären intermitochondrialen Substanz eingebettet. Typ II besteht aus einer ebenfalls kugeligen Ansammlung vieler kleiner radiär angeordneter Golgi-Stapel, welche in der gleichen dichten, teils granulären, teils fibrillären Substanz liegen wie die Mitochondrien von Typ I. Die Funktion beider Typen von Dotterkernen wird diskutiert. Sicherlich haben sie nichts mehr mit der Dottersynthese zu tun wie möglicherweise die Dotterkerne der Oocyten, doch gibt es bisher auch keine Anzeichen dafür, daß sie bevorzugt am Dotter- oder Lipidabbau beteiligt sind.
    Notes: Summary In all blastomeres of Nassarius from 4- to 16-cell stage yolk nuclei occur. Most of them are spherical bodies, lying juxtanuclearly between the nucleus and the apical plasmalemma. Strangely they are not ultrastructurally uniform but fall into two categories (Fig. 5): Type I is a massive spherical accumulation of mitochondria embedded in a dense intermitochondrial substance, which appears to contain both granules and filaments. Type II is a ball of radially arranged small Golgi stacks clustered around a centre of Golgi vesicles and other organelles embedded in a ground cytoplasm structurally similar to the intermitochondrial substance of type I. The function of both types of yolk nuclei is unknown. These segmentation yolk nuclei have nothing to do with yolk synthesis any more. On the other hand there are no indications that yolk nuclei occurrence is correlated with the break-down of yolk because neither lipid droplets nor protein yolk granules are observed in or beside the yolk nuclei.
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  • 83
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    Keywords: Synapses ; Embryo (Xenopus laevis) ; Spinal cord ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary The rostro-caudal gradient of differentiation found in vertebrate embryos has been utilized to examine the sequence of synaptic junction development in the spinal cord of Xenopus laevis at a late embryonic stage. Uniform samples were taken at various points along the cord of a stage 27 embryo and examined in the electron microscope. The general ultrastructure of the cord demonstrated the rostro-caudal gradient of development. The sequence of synaptic junction development was like that in the cervical region (Hayes and Roberts, 1973). “Membrane-vesicle clusters” and “immature” synaptic junctions were found most caudally followed by synaptic junctions, first with cleft and subsynaptic membrane density, then with only cleft density and finally, most rostrally, with cleft, subsynaptic membrane, and subsynaptic cytoplasmic density. Mature synaptic junctions were found in increasing numbers from the mid to anterior trunk cord and could mediate alternating trunk flexions made by the embryos at this stage of development. “Membrane-vesicle clusters” were found near processes containing irregular vesicles and also near membrane outlines. These may be signs of dendritic growth. “Membrane-vesicle clusters” were also found in varicosities, facing the space around the spinal cord and in nerve fibres peripherally between the skin and myotomes. This suggests an association of early stages in synaptogenesis with axon growth. This and other possible inferences about axon and dendrite growth in relation to synaptogenesis are discussed.
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    Cell & tissue research 153 (1974), S. 293-305 
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    Keywords: Ascidia (Botryllus schlosseri) ; Metamorphosis ; Muscle tissue involution ; Phagocytes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The caudal musculature of the free-swimming tadpole of the ascidian, B. schlosseri consists of cylindrical mononucleated cells connected in longitudinal rows flanking the axial notochord. During resorption of the larval tail, which is apparently induced by the contraction of the epidermis, muscle cells are dissociated and pushed into the body cavity where most of them are rapidly engulfed by phagocytes. In the initial stages of tail withdrawal muscle cells display surface alterations due to the disruption of intercellular junctions and disarrangement of myofibrils. Extensive degenerative changes, with shrinkage of mitochondria and disintegration of the contractile material are subsequently observed. Lysosomes and autophagic vacuoles are rarely seen and appear to play a secondary role in the degradation of the muscle cells, which occurs predominantly within the phagocytes. Myofilaments and myofibrils have never been observed within autophagic vacuoles. Clumps of muscle fragments and degenerated phagocytes undergo eventual dissolution in the blood lacunae, concomitantly with the differentiation of the young oozooid.
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  • 85
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    Cell & tissue research 153 (1974), S. 497-515 
    ISSN: 1432-0878
    Keywords: Arcuate nucleus ; Hypothalamus ; Sexual cycle ; Ribbon-rolls ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Changes in subcellular structures of arcuate neurons correlated in a consistent way with stages of the estrous cycle of the rat. Associated with the rough endoplasmic reticulum short ribbons of moderately electron dense material appeared at metestrus and circular or elliptical bodies termed “ribbon-rolls” at diestrus and proestrus. Although present in proestrus, the ribbon-rolls were smaller at this stage. In a few neurons in diestrous females and in ovariectomized animals one to seven months before perfusion multiple large ribbon-rolls occupied much of the cytoplasm. Also, frequency of dense granules and lysosomes increased in diestrus. The significance of the ribbon-rolls and changes in other structures during the estrous cycle are discussed.
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  • 86
    ISSN: 1432-0878
    Keywords: Urinary bladder ; Frog ; Water permeability and Ultrastructure ; Hyperosmolarity ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Resumé Certaines informations récentes (voir introduction) nous ont conduits à reconsidérer la possibilité que l'action de l'hormone antidiurétique sur les tissus épithéliaux puisse s'exercer au niveau des jonctions intercellulaires. Une étude comparative des cinétiques d'apparition des altérations ultrastructurales et des variations de perméabilité à l'eau a permis d'établir que les décollements de la “tight junction” provoqués par l'hyperosmolarité muqueuse apparaissent avant tout accroissement significatif du flux net d'eau et ne peuvent donc pas en être la conséquence. L'examen à haute résolution, par cryodécapage, de la structure de la “tight junction” montre l'apparition dans ces conditions de plages plus ou moins circulaires où la membrane présente un aspect lisse et apparemment distendu et où la structure typique de la “tight junction” a disparu. Ces modifications rétrocèdent après stimulation hormonale et ceci conduit à penser qu'elles ne sont pas impliquées dans la réspone hydrosomotique physiologique.
    Notes: Summary The role of the tight junction in the hydrosmotic response of the frog urinary bladder has been analysed by comparative kinetic studies and freeze etching examination. The comparison of the time course of the variations in transepithelial water net flux and of the alterations of tight junction ultrastructure in bladders exposed to mucosal hyperosmolar solutions shows that blisters are present in the tight junction before any increase in transepithelial water net flux. This indicates that the two phenomena are dissociated. In the same experimental conditions, freeze etching examination shows the presence in the tight junction of large areas of smooth and apparently stretched membrane where the typical network structure has disappeared. These alterations are reduced by further treatment with oxytocin and are probably not involved in the physiological hydrosomotic response.
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  • 87
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    Cell & tissue research 154 (1974), S. 443-470 
    ISSN: 1432-0878
    Keywords: Oocytes and T-prospermatogonia ; Rat ; Quantitative analysis ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Bei der Ratte findet die sexuelle Differenzierung der Gonade zwischen dem 14. und 15. Tag post conceptionem (p.c.) statt. Während dieser Zeit teilen sich die Oogonien und deren Parallelpopulation—die M-prospermatogonien (multiplying prospermatogonia) oder I-Gonocyten—sehr häufig. Um den 17. Tag p.c. tritt die letzte Generation der Oogonien bzw. der M-prospermatogonien in die Mitose. Die Mitosen bilden häufig “synchronisierte Gruppen”. Die postmitotischen Kerne ihrer Tochterzellen—der Oocyten und der T 1 prospermatogonien (primary transitional prospermatogonia) oder II-Gonocyten—sind klein. Ihr Chromatin ist in Form gröberer Schollen der Kernmembran angelagert. Auf diese Weise kommt das typische “krustenförmige” Aussehen bzw. die Ähnlichkeit mit den Prophasen der Oogonien und M-prospermatogonien zustande. Die Oocyten durchlaufen zunächst die G1-phase (etwa 10 Std Dauer) und treten dann—am Ende des Präleptotänstadiums—in die S-phase. Dann passieren sie die verschiedenen Stadien der meiotischen Prophase und treten vom 3. Tag post partum (p.p.) ab in das Dictyotänstadium. Die T1-prospermatogonien hingegen befinden sich etwa 10 Tage lang in der G1-phase, ohne wesentliche morphologische Veränderungen aufzuweisen. Vom 4. Tag p.p. an durchlaufen sie die S-Phase. Die S-Phasen-Dauer (D-S) beider Zellarten beträgt 11.5 Std und wurde durch Doppelmarkierung mit 14C- und 3H-Thymidin bestimmt. Als am besten geeignete Termine für die Bestimmung der D-S erwiesen sich bei den Oocyten der 18. Tag p.c. und bei den T1-prospermatogonien der 5. Tag p.p. Zu diesen beiden Zeitpunkten war die Anzahl der in die S-phase ein-und austretenden Oocyten bzw. T1-prospermatogonien gleich, die Zellen in S-phase befanden sich im “steady state”. Das Kernvolumen der Oogonien und M-prospermatogonien ist etwa doppelt so groß wie das der postmitotischen Oocyten und T1-prospermatogonien. Bis zum 5. Tage p.p. nimmt das Kernvolumen der Oocyten und T1-prospermatogonien um etwa das Fünffache zu. Der Degenerationsindex der Oocyten liegt wesentlich höher als der der T1-prospermatogonien; er ist postnatal besonders hoch. Aus den T1-prospermatogonien gehen am 4. und 5. Tage p.p. durch Teilung die T 2-prospermatogonien (secondary transitional prospermatogonia) hervor. Die Kerne dieses Zelltyps sind etwas kleiner also die der T1-prospermatogonien. Die T2-prospermatogonien treten am 6. Tage p.p. in die Mitose; es entstehen die ersten A-spermatogonien.
    Notes: Summary In the rat (Wistar-WU) sexual differentiation of the gonads occurs between days 14 and 15 post conception (p.c.). At this time the oogonia and their parallel population — the M-prospermatogonia (I-gonocytes)—divide rapidly. On about day 17 p.c., the last generation of oogonia and M-prospermatogonia, frequently arranged in synchronized clusters, enters mitosis. The postmitotic nuclei of their daughter cells—oocytes and T 1-prospermatogonia (II-gonocytes)—are small; coarse flakes of chromatin are associated with the nuclear membrane causing the typical “crustlike” appearance and the similarity with the prophases of oogonia and M-prospermatogonia. After the oocytes have passed a G1-phase of approximately 10 hr, they enter the S-phase at the end of the preleptotene stage. Then they pass the different stages of the meiotic prophase until they enter the dictyate stage from 3 day post partum (p.p.) onwards. The T1-prospermatogonia, on the other hand, spend a long G1-phase of about 10 days without any conspicuous morphological change before entering the S-phase from day 4 p.p. onwards. The duration of the S-pbase (D-S) of both cell types—oocytes and T1-prospermatogonia—as determined by the double labeling method with 14C- and 3H-thymidine is found to be 11.5 hr. The most favourable time for determining the D-S was day 18 p.c. for the oocytes and day 5 p.p. for the T1-prospermatogonia. On these two days the balance was reached between the cells entering and leaving the S-phase. The nuclear volumes of the postmitotic oocytes and T1-prospermatogonia are approximately half the size of those of their precursors. Until day 5 p.p. the nuclear volumes of the oocytes and T1-prospermatogonia increase about fivefold. The degeneration index of the oocytes is considerably higher than that of the T1-prospermatogonia; postnatally it is especially high. T 2 prospermatogonia arise by mitosis of the T1-prospermatogonia on day 4 and 5 p.p. The nuclei of this cell type are smaller than those of T1-prospermatogonia. T2-prospermatogonia enter mitosis on day 6 p.p and give rise to A-spermatogonia.
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  • 88
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    Cell & tissue research 154 (1974), S. 533-541 
    ISSN: 1432-0878
    Keywords: Myofibroblasts ; Testicular capsule (rat) ; Connective tissue ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A specialized type of fibroblast occurs in the testicular capsule of adult rats. The flattened cells are characterized by bundles of cytoplasmic filaments. Filament bundles run parallel to the cell surface and insert in plaques of granular, electron dense material which is attached to the inner surface of the plasma membrane (attachment zones). Cytoplasmic filaments measure 60–80 Å in diameter. Sporadically plaques of basal lamina-like material are found, especially in the region of attachment zones. These specialized fibroblasts are interpreted as myofibroblasts. It is supposed that contractility of the testicular capsule in rats is caused by myofibroblasts.
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  • 89
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    Cell & tissue research 155 (1974), S. 117-125 
    ISSN: 1432-0878
    Keywords: Sinus gland ; Carcinus maenas (Crustacea, Decapoda) ; Nerve fibre cell types ; Neurosecretion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sinus gland of Carcinus maenas consists of the swollen axonal endings of the neurosecretory cells of the major ganglia and acts as a storage release centre for the membrane bound neurosecretory material. These neurosecretory granules fall into five different types based on size and electron density. Their contents are released by exocytosis of the primary granules or smaller units budded from the primary granules.
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  • 90
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    Cell & tissue research 155 (1974), S. 193-199 
    ISSN: 1432-0878
    Keywords: Microfilaments ; Prolactin cells ; Anterior pituitary ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Prolactin cells from anterior pituitary glands of normal non-lactating female rats, and lactating animals, some of which were separated from their pups for 48 hours, were examined ultrastructurally for the presence of microfilaments. Microfilaments were found in specific intracellular locations in all cells examined. They were in association with the nuclear envelope, the Golgi complex, the endoplasmic reticulum, small vesicles of the endoplasmic reticulum, and secretory granules. The possible role of microfilaments in the movement of intracellular organelles is considered.
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  • 91
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    Cell & tissue research 155 (1974), S. 231-243 
    ISSN: 1432-0878
    Keywords: Pinealocyte-resembling cells ; Habenular region ; Sympathetic nerve fibres ; Ontogenetic development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cells of the pineal gland, the pineal stalk, and the lamina intercalaris contain 5-HT and are innervated by sympathetic nerve fibres. These peripheral nerve fibres continue rostrally from the lamina intercalaris and run into the central nervous tissue of stria medullaris and the habenular nuclei. Pharmacological treatment to increase the cellular 5-HT content revealed that the sympathetic fibres are in close relation to yellow fluorescent cells embedded in the brain tissue. These yellow fluorescent cells develop very late in the ontogenetic development (three weeks or more postnatally) and are preceded by ingrowth of sympathetic fibres into the brain tissue. The results support the hypothesis that the cells found in the habenular region are of pinealocyte rather than neuronal nature, but it is possible that they differ in certain aspects from the cells of the pineal gland proper.
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  • 92
    ISSN: 1432-0878
    Keywords: Neuromuscular junctions ; Development in vitro ; Electron microscopy ; Electrophysiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of neuro-muscular junctions between previously dissociated foetal rat spinal cord and somatic muscle has been investigated. The first indications of junction formation, both ultrastructurally and electrophysiologically, were observed after circa 18 days in vitro. The junctions contained numerous vesicles, but no secondary folds were developed even after 6 weeks in culture, and synaptic densities were not well marked. Functional endplates were found, and action potentials, endplate potentials and miniature endplate potentials recorded.
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  • 93
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    Cell & tissue research 155 (1974), S. 491-512 
    ISSN: 1432-0878
    Keywords: Gills ; Tilapia mossambica ; Arterio-venous anastomoses ; Specialized endothelia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Arterio-venous anastomoses (AVA) in gill filaments of Tilapia mossambica exhibit a distinct polarity. Two different types of highly specialized endothelial cells, both of epitheloid shape, line these vessels: Type I cells, contacting the arterial lumen, are elongated and about two to three times as large as type II endothelial cells. Their surface is increased by tentacular protrusions which reach far into the arterial lumen. Filament whorls forming tubelike structures with centrally located glycogen granules are abundant in these cells. Type II endothelial cells are located proximal to the central venous sinus (CVS). Their less abundant and more electron dense cytoplasm is free of filament whorls. There are also intermediate cell forms at approximately the middle of each anastomosis. Short cell processes protrude from all endothelial cell types into the AVA lumen. Outside the indistinct vascular basement lamina, a layer of cover cells tightly envelopes the AVA. These cells are, however, absent around the part of the AVA adjacent to the CVS. Here the endothelial cells are in immediate contact with the interstitium. Endothelial cells sheathed by cover cells reach the interstitium through basal foot processes. Nerve fibre bundles regularly come into close contact with the AVAs. Possible functions of the AVAs, including osmoreception are discussed.
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  • 94
    ISSN: 1432-0878
    Keywords: Avian follicles ; Oocytes ; Transosomes ; Lysosomes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy has been utilized to determine fates of sacs of ribosomes (variously termed “transosomes”, “unique organelles”, or “lining bodies”) formed in the follicular cells of avian follicles and subsequently entering-or being taken in-by the oocytes. Small follicles (0.5 mm diameter) of laying hens, a hen afflicted with Marek's disease and prelaying pullets were examined in this regard. In the case of the hen with Marek's disease and the prelaying pullets, sacs of ribosomes were found to be present within the oocyte but those present in the interior of the cell were in the form of digestive vacuoles. In a fourth group of hens, receiving actinomycin D, larger oocytes (2.0 mm diameter) exhibited breakdown of the membranous vesicles in which the sacs of ribosomes entered the oocyte, as well as dissolution of membranes surrounding the forming yolk granules and the membranes of coated vesicles. Annulate lamellae were present in oocytes of the hen afflicted with Marek's disease and appeared within at least 24 hours in oocytes from hens receiving actinomycin D.
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  • 95
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    Cell & tissue research 147 (1974), S. 589-593 
    ISSN: 1432-0878
    Keywords: Ommatidium ; Apis mellifica ; Ninth retinula cell ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Rhabdom im Ommatidium der Arbeitsbiene wird von 9 Retinulazellen aufgebaut. Die exzentrische Zelle = Zelle Nr. 9 (ca. 50–75 μ lang) liegt im distalen Bereich des Ommatidiums, unterhalb der Zelle Nr. 4 (nach Varela und Porter, 1969), die ihrerseits den Rhabdomverband verläßt und als Axon zur Basalmembran zieht.
    Notes: Summary The rhabdom in the ommatidium of the worker honey bee is built up of 9 retinula cells. The eccentric cell = cell No. 9 (approx. 50–75 μ long) is situated in the distal region of the ommatidium beneath the fourth cell (numbered according to Varela and Porter, 1969), which in its turn leaves the rhabdom and runs as an axon towards the basement membrane.
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  • 96
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    Cell & tissue research 148 (1974), S. 499-504 
    ISSN: 1432-0878
    Keywords: Urethra (rat) ; Chromaffin cells ; Sensory neurons ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The urethra of the rat was examined by transmission and scanning electron microscopy. Under a transmission electron microscope flask-shaped chromaffin cells containing membrane-bound osmiophilic granules were seen to possess microvilli at their apical surfaces. The microvilli projected into large extracellular spaces which were apparently in continuity with the lumen of the urethra. Using scanning electron microscopy, a surface view of the lumen of the urethra was obtained. It showed a gently undulating surface with distinct intercellular boundaries. Scattered over the surface were numerous deep depressions between individual cells. These were thought to correspond with the large extracellular spaces into which microvilli had been seen to project. It is suggested that urethral chromaffin cells may “trigger” the afferent part of a reflex causing contraction of the urethral longitudinal muscle.
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  • 97
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    Cell & tissue research 148 (1974), S. 535-550 
    ISSN: 1432-0878
    Keywords: Synaptosomes ; Rat brain stem ; Synaptogenesis ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure and protein content of the five subfractions of the crude mitochondrial fraction from the brain stem of the 1-day old and adult rat was examined. The morphological composition of the subfractions after fixation in glutaraldehyde and osmiumtetroxide in the adult rat brain stem resembled that previously reported for the whole brain; synaptosomes sedimented in a sucrose gradient in subfractions C and D. In the 1-day old rat, mature synaptosomes were found in subfractions A, B, C and D; E contained mainly free mitochondria. 80–95% of the processes in the adult and 10–30% in the 1-day old rat contained synaptic vesicles which were of four types: (1) small agranular vesicles (2) large dense core vesicles (3) large agranular vesicles (4) coated vesicles. Pre- and postsynaptic membrane thickenings were demonstrated in many nerve-ending particles. In the subfractions of the 1-day old rat the protein content was one half and the distribution resembled that in the adult. Evidently nerve endings develop faster in the brain stem than in cortical areas; a serotoninor adrenergic origin of the early synaptosomes is suggested.
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  • 98
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    Cell & tissue research 149 (1974), S. 313-327 
    ISSN: 1432-0878
    Keywords: Follicle rupture ; Rabbit ; Ovary surface epithelium ; Induced ovulation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To elucidate the intra-ovarian mechanism of follicle rupture, young, sexually mature rabbits were oophorectomized at accurately determined times after an ovulatory dose of human chorionic gonadotrophin (HCG), and the surface epithelium of Graafian follicles was studied by transmission electron microscopy. At 4 hr after injection of HCG the surface epithelial cells are considerably larger than earlier and many of them show large, round, dense, cytoplasmic bodies, particularly in the apical region of the preovulatory follicles. Up to 8 hr after injection of HCG there is a gradual accumulation of the large, dense bodies; from then on they markedly decrease in amount. Recently reported values of prostaglandins in rabbit Graafian follicles at various times after ovulatory stimulation and of steroid hormone levels in the Graafian follicle and the ovarian vein have been correlated with the ultrastructural changes. Both sex steroids and prostaglandins can labilize lysosomal membranes (and presumably other membranes as well) and may thus cause leakage of lytic enzymes. The large dense bodies of the apical surface epithelium of preovulatory follicles may represent an important source of (lysosomal) enzymes to effect weakening of the follicle wall and rupture of the follicle apex in a fairly constant area, the stigma.
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  • 99
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    Cell & tissue research 149 (1974), S. 555-566 
    ISSN: 1432-0878
    Keywords: Spermatogenesis ; Spermatid ; Campodea (apterygota) ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé A un certain stade de leur évolution, les spermatides de Campodea C. remyi Denis sont réunies en petites touffes de 236 á 650 éléments. Leurs acrosomes sont implantés dans une substance homogéne (ciment) assez dense aux électrons. La spermatide comprend une région acrosomienne et une région postacrosomienne où sont alignés parallèlement: l'axonème, les deux dérivés mitochondriaux et le noyau. L'acrosome est assez long, il est renforcé par 7 à 10 microtubules. L'axonème est du type 9+9+2; les mitochondries sont de longueur presque égale. Le noyau plus court, montre une chromatine très dense aux électrons. Au niveau de la région postérieure du noyau, la membrane cytoplasmique se replie sur elle-même pour former une sorte de collerette ouverte vers l'arrière. En région distale de la spermatide, on observe au niveau d'un élargissement, une superposition de structures lamellaires.
    Notes: Summary The spermatids of Campodea C. remyi Denis are clumped in small bundles of 236 to 650 elements during spermiogenesis, their acrosomes being embedded within an homogeneous electron dense material. The spermatid comprises an acrosomal region and a postacrosomal region within which, the two mitochondrial derivatives and the nucleus are arranged in parallel. The acrosome is rather long, it is reinforced by seven to ten microtubules. The axoneme is of the 9+9+ pattern. The mitochondria are of almost equal length. The shorter nucleus shows a very electron dense chromatin. At mid-nuclear level the cytoplasmic membrane is folded up to form a sort of collar opening backwards. Distal to the nucleus, superimposed lamellar structures are found located in an expanded part of the spermatid.
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  • 100
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    Cell & tissue research 149 (1974), S. 105-111 
    ISSN: 1432-0878
    Keywords: Sperm flagella ; Motility ; Axonemal variation ; Axonemal evolution ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The flagella of the motile sperm cells of Nymphon leptocheles and N. rubrum (Pyonogonida, Arthropoda) exhibit a 12+0 and a 9+0 axoneme pattern, respectively. Central tubules, central sheath, spokes and arms are absent. The doublets are connected by a circular nexus. The functional significance of this axonemal composition is discussed. Aberrant axonemes occurring in high frequencies both within the species and within single specimens are probably explained by the loose axonemal connection, due to the absence of a central complex. This absence is further suggested to have facilitated the evolution from the 9+0 type to the 12+0 type.
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