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  • Articles: DFG German National Licenses  (108)
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  • Articles: DFG German National Licenses  (108)
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  • 1975-1979  (72)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 31 (1978), S. 433-443 
    ISSN: 1432-1106
    Keywords: Rat ; Soleus ; Fusimotor innervation ; Skeletofusimotor innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the small segmental tail muscles of the rat beta fibres provide exclusively the dynamic fusimotor control, while gamma fibres provide exclusively the static fusimor control. The present experiments were made to investigate the fusimotor innervation of spindles in a large muscle of the rat, the soleus, and thus to determine the occurrence and significance of beta innervation in this muscle. Our results have revealed no case of beta innervation in the rat soleus. As a consequence of our experimental method, however, we would not claim that beta innervation does not exist in the soleus, only that it must play an insignificant role relative to that seen in the tail segmental muscles. Investigations of the fusimotor innervation of eight spindles were sufficiently complete to warrant detailed illustration. The number of gamma fibres ranged from two to four. In every case the slowest conducting gamma fibre was dynamic. However, the conduction velocity spectra for the static and dynamic gamma fibres to rat soleus overlap to such an extent that it is impossible to use conduction velocity as the sole guide to functional gamma fibre classification. The pooled results from the eight spindles fully investigated provide a ratio of static to dynamic gamma fibres of approximately 1:1. Other evidence discussed in the paper suggests that in the muscle nerve the ratio is considerably higher. These differences are reconciled if the dynamic gamma fibres branch more profusely and innervate more spindles than do the static gamma fibres.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 31 (1978), S. 573-590 
    ISSN: 1432-1106
    Keywords: Hippocampus ; Place units ; Unit recording ; Sensory cues ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Place units in the dorsal hippocampus of the freely-moving rat signal the animal's position in an environment (place field). In the present experiments, thirty four place units were recorded in two different environments: one, a small platform where the rat had received neither training nor reward; the other, an elevated T-maze inside a set of black curtains where the rat had been trained on a place discrimination. The places within the curtained enclosure were specified by four cues (a light, a card, a fan, and a buzzer) in addition to the food. Other cues were eliminated by rotating the maze and the four controlled cues relative to the external world from trial-to-trial. Some units had place fields in both environments while others only had a place field in one. No relationship could be seen between the place fields of units with fields in both environments. All twelve units tested extensively in the controlled enclosure had place fields related to the controlled cues. Probe experiments in which only some of the controlled cues were available showed that some of these units were being excited by one or two cues while others were influenced in a more complex way. The fields of these latter units were maintained by any two of the 4 cues and were due to inhibitory influences which suppressed the unit firing over the rest of the maze.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 32 (1978), S. 365-375 
    ISSN: 1432-1106
    Keywords: Intraspecific aggression ; Lateral hypothalamus ; Electrical stimulation ; Specificity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of electrical stimulation of the lateral hypothalamus (LH) of rats on intraspecific aggressive behaviour were studied. In order to investigate the specificity of the stimulation effects, each experimental animal was stimulated in a number of different social situations. Stimulation of the LH in the presence of a subordinate male increased the amount of time spent on aggressive behaviour patterns and locomotion. In the presence of a dominant male, however, the stimulated animal never initiated a fight, whereas in the presence of an estrous female attack occurred in some rare occasions and sexual behaviour disappeared almost entirely. Stimulation of some sites also elicited mouse killing behaviour. Many of the electrodes that elicited intraspecific aggressive behaviour also supported intracranial self-stimulation. It is concluded that 1. electrical stimulation of this area of the LH predominantly potentiates intraspecific aggressive behaviour, 2. that this behaviour becomes overt depends on the external situation, including the behaviour of the opponent.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 33 (1978), S. 213-225 
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Axotomy ; ATP-ase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The hypoglossal nuclei of adult male albino rats, either normal, or from 1 to 70 days after left hypoglossal nerve transection, were studied cytochemically with a lead method for sodium- and potassium-activated membrane ATP-ase, using light and electron microscopy. Reaction product was measured at the light microscopical level by microdensitometry, and significance determined statistically. Light microscopy revealed a brown reaction product in the neuropil, but none in cell bodies. Blood vessel walls were more strongly coloured. Reaction product was undiminished by ouabain pre-incubation, or by incubation without sodium or potassium, or by incubation with calcium instead of magnesium. Reaction product was diminished by absence of magnesium if calcium was also absent, and abolished if sections were boiled before incubation, or if substrate was absent. Axotomy caused a statistically significant increase in neuropil reaction product in injured nuclei, maximal at 35 days postoperatively, and subsequently decreasing to normal at 70 days. Electron microscopy showed a predominantly surface membrane reaction product, with occasional positive intracellular cisternae. Basal lamina and intra-endothelial vacuoles were also positive. Axotomy resulted in the arrival and disappearance of microglia (2 to 35 days), followed by astrocyte hypertrophy (35 days), and increase in thickness and homogeneity of surface membrane reaction product. The results suggest the presence of one or more calcium- or magnesium-dependent membrane ATP-ases. The peak of the increase after axotomy is probably partly attributable to hypertrophic astrocytes, and partly to the surfaces of neuronal processes. Increase of membrane movements might explain such enzyme activity.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 56 (1978), S. 211-215 
    ISSN: 1432-2072
    Keywords: Chlordiazepoxide ; d-Amphetamine ; Response force ; Punishment ; Stereotyped behavior ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were reinforced with water on a continuous reinforcement schedule and were also punished with electric shock for every fifth response applied to a silent, isometric, force-sensing manipulandum. Oral doses of chlordiazepoxide (3.0, 9.0, 27.0 mg/kg) increased both conventional rate and force of punished responding. In contrast, d-amphetamine (0.8, 1.6, 3.2 mg/kg, by gavage) further decreased conventional rate and force of response, but this latter drug increased the rate of recorded responses that were lower than the 15-g force criterion for response consequences. The results for chlordiazepoxide are viewed in terms of its anxiolytic properties, while the d-amphetamine data appear to support a theory of amphetamine effects based on the concept of stereotyped behaviors.
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  • 6
    ISSN: 1432-2072
    Keywords: Ethanol ; Tolerance ; Behavioral augmentation ; Physical dependence ; Carry-over ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Adult male rats were subjected to 1–4 cycles of daily gastric intubation with ethanol (6 g/kg) for 16 days, separated by 17-day alcohol-free periods. Tolerance produced by this treatment (designated ‘physiological tolerance’) was measured by change in effect of a 2.2 g/kg i.p. dose of ethanol on the moving-belt test. It occurred in each cycle, disappeared completely in the drug-free periods, and developed more rapidly in the second and later cycles than in the first. Tolerance produced by the ‘behavioral augmentation’ technique (daily test practice under the influence of ethanol) also developed more rapidly on a second than on a first cycle. The progression from within-session to between-session tolerance was still evident, but accelerated. With 25-day alcohol cycles, separated by a one-month drug-free period, the ‘carry-over’ effect (i.e., more rapid acquisition of tolerance in the second cycle) applied equally, regardless of whether or not tolerance was produced by the same technique in both cycles, or by a crossover in either direction between the two techniques.
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  • 7
    ISSN: 1432-2072
    Keywords: Polyphloretin phosphate ; Prostaglandins ; Behaviour ; Temperature ; Bram biogenic amines ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The possibility that polyphloretin phosphate (PPP) antagonizes the central effects elicited by prostaglandin (PG) E2 and F2α was investigated. PPP was administered i.c.v. to male Wistar rats (10 or 25 μg) 10 or 30 min before i.c.v. injection of PGE2 or PGF2α (1 or 10 μg). The duration of several components of behavior, the degree of irritability, and the rectal temperature of rats were measured; the levels of noradrenaline, dopamine, 5-hydroxytryptamine, and 5-hydroxyindoleacetic acid were measured spectrophotofluorometrically in discrete brain areas. PPP antagonized temperature and behavioral changes induced in rats by PGF2α, but not those induced by PGE2. The magnitude of antagonism depended on the dose of PPP and on the time of the pretreatment before PGF2α administration. Changes in the level of biogenic amines in discrete brain areas evoked by PGs were not affected by PPP. We found that PPP antagonizes the central effects of PGF2α but not those of PGE2, and that changes of biogenic amines in discrete brain areas elicited by PGs are not specific.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 378 (1978), S. 45-53 
    ISSN: 1432-2307
    Keywords: Alcohol ; Myopathy ; Histochemistry ; Electrophysiology ; Human ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Muscles of the lower legs of rats given 25% ethanol in water ad libitum for up to 9.5 months were studied using histological, histochemical and electrophysiological techniques. Ethyl alcohol was substituted for about 20% of the total calorific input of the animals. The observations were compared with the structure of the gastrocnemius muscle of five alcoholics with clinical neuropathy. Fibrillation potentials and angulated atrophic fibers were observed in the muscles of animals on alcohol for 9.5 months. No fiber type grouping was present. There was also phagocytosis of the muscle fibers and changes in their internal structure, as reflected by the distribution of NADH-diaphorase. The observed muscle changes in the alcoholics and those in the experimental animals on alcohol differed mainly quantitatively, the only exception being the presence of fiber type grouping in the biopsies from the alcoholics.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 173 (1978), S. 239-244 
    ISSN: 1433-8580
    Keywords: Experimental chronic uremia ; Rat ; Oxygen consumption ; Body weight ; Experimentelle chronische Urämie ; Ratte ; Sauerstoffverbrauch ; Körpergewicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die verminderte Gewichtszunahme bei experimenteller chronischer Urämie führte zu der Bestimmung des Sauerstoffverbrauches chronisch urämischer Ratten und eines normalen Vergleichskollektivs. Die Messung des Sauerstoffverbrauches wird als Hinweis auf den Energiebedarf des Gesamtstoffwechsels gewertet. Drei Gruppen von Versuchstieren wurden untersucht: urämische Ratten (CU) von geringerem Gewicht (403,66 ± 9,9 g) als deren gesunde Vergleichstiere (NA) (498,31 ± 26,13) und jüngere Normaltiere (NJ), welche ein annähernd ähnliches Körpergewicht wie die chronisch Niereninsuffizienten aufwiesen (376,0 ± 8,8). Signifikante Unterschiede des Sauerstoffverbrauches, bezogen auf das Körpergewicht, wurden zwischen den Gruppen NJ (0,927 ± 0,042 ml O2/mn/100 g Ratte) und beiden Gruppen CU und NA (0,788 ± 0,036 und 0,788 ± 0,028 jeweils) gefunden. Eine proportionale Verminderung der energetisch aktiven Körpermasse mag die Ursache der Sauerstoff-Meßergebnisse bei chronischer experimenteller Urämie sein.
    Notes: Summary Impaired weight gain, a common feature in experimental chronic uremia, led to compare oxygen consumption values of chronic uremic rats and their controls. Oxygen consumption measurement may allow an approach to the evaluation of total energy requirement. Three groups of animals were considered: uremic rats (CU) of less weight (402.66 ± 9.9 g) than their control group (NA) (498.31 ± 26.13) and younger normal animals (NJ), showing a similar weight (376.0 ± 8.8) to that of the uremics. Significant differences in oxygen consumption values/body weight were found between group NJ (0.927 ± 0.042 ml O2/mn/100 g rat) and both groups CU and NA (0.788 ± 0.036 and 0.788 ± 0.028 respectively). Proportional decrease of energetically active body mass in chronic uremic animals may be the reason of the findings.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 174 (1978), S. 57-65 
    ISSN: 1433-8580
    Keywords: Complement system ; Sodium taurocholate ; Acute experimental pancreatitis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The role of the complement system was studied in Na-taurocholate pancreatitis in rats. Complement activity (CH 50) was determined at various times in the course of pancreatitis. Immediately after induction of acute pancreatitis, serum complement activity declined and massive C 3 deposits could be detected in the vicinity of acinar necroses and necrobioses. After a phase of recovery three to six hours postoperatively a second complement consumption occurred. Lethality rate increased as serum complement activity fell below 50% of preoperative values. The degree of C 3 deposition increased up to six hours. Decline of serum complement activity and deposition within the pancreas seemed to be correlated with histologically demonstrable tissue lesion. The first decline of complement activity in serum is thought to be caused by liberation of complement activating substances within the pancreas due to the detergent action of Na-taurocholate itself. The second decline, however, may be due to the liberation of complement activating and/or destroying enzymes into the blood stream.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 172 (1978), S. 247-253 
    ISSN: 1433-8580
    Keywords: Rat ; Parotid saliva
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A method is described, which is suitable to collect continuously and quantitatively saliva from both parotid glands in rats under in vivo conditions and which allows to investigate salivary electrolyte composition in relation to flow rate during several hours. This might be of expanding scientific interest in disturbances of transepithelial electrolyte transport in various pathophysiological situations (for instance different forms of experimental hypertension, endstage renal failure and so on).
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 154 (1978), S. 27-37 
    ISSN: 1432-0568
    Keywords: Capillarization ; Cortex ; Rat ; 6-Aminonicotinamide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary During different embryonic and postnatal stages, 6-aminonicotinamide (6-AN) was administered to Wistar albino rats. The capillarization of the occipital cortex has been examined morphometrically. A 6-AN-vulnerable stage of prenatal development was found, which lasted to the 19th prenatal day and which only partly corresponds to the so-called ‘critical stage’ of capillary sprouting (Kapillarsprossung). Capillary sprouting was not impaired by 6-AN during postnatal stages. Impairment of capillarization by 6-AN might be the result of glial lesion. The importance of glia for capillarization is discussed.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 153 (1978), S. 1-8 
    ISSN: 1432-0568
    Keywords: Ileal epithelial cell ; Suckling period ; Rat ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ileal epithelial cells containing the tubulo-vacuolar systems and supranuclear vacuoles in suckling rats were investigated with scanning electron microscopy, using specimens treated with osmium-thiocarbohydrazide-osmium staining methods, and critical point drying and cracking. The cracked surface of the apical cytoplasm is seen as irregular and small hollows and pores of the anastomosing and branching tubulo-vacuolar system. The cracked surface of the supranuclear vacuoles shows the ellipsoidal structures. Numerous pores of various size and irregular shape are present on the apical inner surface of the supranuclear vacuole. These pores are clearly the openings from the tubulo-vacuolar system to the supranuclear vacuole. Some small pores are visible on the inner lateral surface of the supranuclear vacuole, especially near the nucleus. They are probably the pathways of the absorbed materials from the supranuclear vacuole into the lateral cytoplasm. Usually, the inclusions of the supranuclear vacuole reveal the globes or coarse and sponge-like networks.
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  • 14
    ISSN: 1432-0568
    Keywords: Rat ; Iris ; Cornea ; Catecholamine fluorescence ; Cholinesterase ; Histochemistry ; Ontogenesis ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Glyoxylic acid-induced fluorescence technique and a copper thiocholine method were used to investigate the ontogenesis of the catecholamine-containing and cholinesterase-positive nerves of the rat iris and cornea. First fluorescent nerve fibres appeared in the iris on the 18th gestation day and in the cornea on the 19th day. A rapid increase in the density of the adrenergic nerve fibres of the iris continued to the age of three weeks, while the number of such fibres were small in the cornea. Acetylcholinesterase-positive fibres appeared both in the cornea and in the iris on the 19th gestation day. Their density increased more rapidly in the iris, especially in the sphincter muscle, than in the cornea. Non-specific cholinesterase activity was localized in the Schwann cells and the reaction was more intense during development than in the nerves of the cornea of adult rats.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 154 (1978), S. 241-251 
    ISSN: 1432-0568
    Keywords: Nervous system ; Serotonin ; Raphe nuclei ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pre- and early postnatal development of serotonin neurons in the rat brainstem was studied using the fluorescence histochemical method. The technique utilized does not require drug pretreatment to visualize an intense serotonin fluorophore localized in neuronal perikarya, dendrites, and axons. All the serotonin neuron groups develop as bilateral nuclei which extend from the midbrain through the medulla. Six of the nine groups undergo a midline fusion from embryonic day 18 (E 18) through postnatal day 6 (P 6) in a rostrocaudal gradient. Cells of the nucleus raphe dorsalis fuse first (by P1), whereas the serotonin neurons located in nucleus raphe pallidus do not fuse until P 6. This gradient is comparable to the one described for the first observable fluorescence in the serotonin neurons groups. After final cell division, the serotonin neurons undergo a primary migration from the ventricular zone along the midline, where they are situated during embryogenesis, and a secondary migration extending into postnatal life which concludes with fusion in the midline. The bilateral origins of the serotonin cell groups are maintained in the adult. This is expressed by the apparent ipsilateral projections of some of the raphe neurons determined recently in our laboratory utilizing autoradiographic and horseradish peroxidase techniques.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Annals of hematology 37 (1978), S. 295-306 
    ISSN: 1432-0584
    Keywords: Β-adrenerge Rezeptoren ; (3H) (−) Dihydroalprenolol ; Erythrozyten ; Ratte ; Β-Adrenoceptors ; (3H) (−) Dihydroalprenolol ; Erythrocytes ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary By means of the radioactive antagonist ligand (3H) (−) dihydroalprenolol (DHAP) specific binding sites were identified in membrane preparations from red blood cells from rats. These specific sites were characterized asΒ-adrenoceptors because of the following reasons: Specific binding of DHAP (in contrast to unspecific binding) was dependent on temparature and time of incubation. Furthermore, specific binding of DHAP showed saturability, temperature-dependent reversibility and high affinity (KD-value of DHAP = 6.51 nM). Specific binding of DHAP was competitively inhibited byΒ-adrenergic antagonists (pindolol 〉 alprenolol ≧ propranolol 〉 practolol) and agonists (isoprenaline 〉 adrenaline). The (−) enantiomers of pindolol and isoprenaline showed pronounced higher affinities for the receptor sites than the respective (+) enantiomers. The receptor density in the membrane preparations (pmoles/mg protein) was strongly dependent on the degree of reticulocytosis: The Bmax-values increased more than 4 to 5 fold without alteration of the respective KD-values when reticulocyte counts were enhanced from 3 to 80 % treatment of the animals with increasing doses of acetyl phenylhydrazine.
    Notes: Zusammenfassung Mittels des radioaktiv markierten Antagonist-Liganden (3H) (−) Dihydroalprenolol (DHAP) wurden spezifische Bindungsstellen in Membran-PrÄparationen von Erythrozyten der Ratte identifiziert, die aus folgenden Gründen alsΒ-adrenerge Rezeptoren angesprochen werden können: Im Gegensatz zur unspezifischen Bindung von DHAP war die spezifische Bindung abhÄngig von der Inkubationszeit und der Temperatur. Sie folgte einer SÄttigungskinetik, war — in AbhÄngigkeit von der Temperatur — reversibel und wies eine hohe AffinitÄt auf (KD für DHAP = 6,51 nM). Die rezeptorspezifische Bindung von DHAP wurde durchΒ-Rezeptorenblocker (Pindolol 〉 Alprenolol ≧ Propranolol 〉 Practolol) oderΒ-Sympathomimetika (Isoprenalin 〉 Adrenalin) kompetitiv gehemmt. Die (−) Enantiomeren von Pindolol und Isoprenalin hatten eine wesentlich höhere AffinitÄt als die antsprechenden (+) Enantiomeren. Die Dichte Β-adrenerger Rezeptoren (pmole/mg Eiwei\) nahm mit steigendem Retikulozytosegrad zu: Sie stieg auf das 4-bis 5fache an, wenn die Retikulozytenwerte durch Vorbehandlung der Tiere mit Azetylphenylhydrazin von 3 auf 80 % gesteigert wurden.
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  • 17
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    Electronic Resource
    Springer
    Archives of dermatological research 262 (1978), S. 167-172 
    ISSN: 1432-069X
    Keywords: Rat ; Oxygen uptake ; Induced skincycle ; Spontaneous skincycle ; Diurnal rhythm ; Ratte ; Sauerstoffverbrauch ; Induzierter Hautcyclus ; Spontaner Hautcyclus ; Tagesschwankung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der vom Panniculus carnosus gereinigten “glatten” Rattenhaut wurde der Sauerstoffverbrauch des spontanen und induzierten Hautcyclus zu verschiedenen Tageszeiten ermittelt. Das Niveau des Sauerstoffverbrauches korrelierte mit den Tag-Nacht-Zeiten. Der Sauerstoffverbrauch zeigte während des Hautcyclus Schwankungen. Ferner fanden sich Anhaltspunkte, daß der frühanagene Wert des Sauerstoffverbrauches von der Cyclusphase mit beeinflußt wird, während welcher der neue Cyclus künstlich induziert wird. Weiter wurde festgestellt, daß eine gewisse Abnahme des Sauerstoffverbrauches die ruhenden Haarfollikel zur spontanen Proliferation anregt. Während des Katagen schien der Maximalwert des Sauerstoffverbrauches mit speziellen morphofunktionellen perifollikulären Veränderungen in Beziehung zu stehen. Die Übertragung dieser Befunde auf die Pathophysiologie menschlicher Haarwachstumsstörungen wird erwogen.
    Notes: Summary In the “clean” rat skin purified from the panniculus carnosus the oxygen consumption of the spontaneous and artificially induced skincycle was measured at different times of day. The level of oxygen consumption correlated to diurnal and nocturnal periods. During the skincycle the oxygen consumption showed fluctuations. There were indications that the value of oxygen consumption of the early anagen is influenced by that phase of the cycle at which the new cycle is artificially induced. Furthermore, it was found that a certain decrease of oxygen consumption stimulates the quiescent hair follicles to spontaneous proliferation. During the katagen the peak value of the oxygen consumption seemed to be correlated with specially morphofunctional perifollicular changes. The application of these findings to the pathophysiology of human hair growth disturbances is discussed.
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  • 18
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    Acta neuropathologica 42 (1978), S. 159-164 
    ISSN: 1432-0533
    Keywords: Perhexiline maleate ; Pexid ; Abnormal inclusion ; Rat ; CNS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The basic cellular lesion in CNS of suckling rats treated with Pexid was studied by light and electron microscopy. The most pronounced abnormality, the formation of various intracytoplasmic inclusions, was found in neurons, astrocytes, oligodendrocytes, ependymal cells, endothelial cells and fibroblasts. These abnormal inclusions were generally membrane-bound, although clearly non-membrane-bound inclusions were occasionally found. The several internal patterns of the inclusions were (1) lamellar, both concentric and parallel, (2) reticular and (3) crystalloid. These alterations were completely resersed following withdrawal of the drug. The structural characteristics of the abnormal inclusions in Pexid-treated animals were similar to those found with certain hypocholesterolemic, neuroleptic, anorectic, and antimalarial drugs. This suggests that the inclusions occurring within the cells of animals treated with any of these drugs may develop in a similar manner, and that the formation of such inclusions is likely to be a form of cellular reaction common to certain metabolic disturbances.
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  • 19
    Electronic Resource
    Electronic Resource
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    Acta neuropathologica 44 (1978), S. 53-56 
    ISSN: 1432-0533
    Keywords: Blood-brain barrier ; Air embolism ; Horseradish peroxidase ; Cerebral cortex ; Electron microscopy ; Carotid artery ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Male albino rats were anaesthetized with diazepam, injected with horseradish peroxidase and Evans blue-labeled albumin and given an embolus of 0.01 ml air in the right common carotid artery after ligation of the external carotid branch. The pial arteries of the right cerebral hemisphere were stained blue, particularly the middle cerebral artery and its main arterial branchlets. Ultrastructurally, some endothelial cells in the right middle cerebral artery, small arteries and arterioles showed a diffuse distribution of horseradish peroxidase in their cytoplasm, although these vessels only occasionally showed peroxidase in their basement membranes. Other endothelial cells in these arterial branchlets showed few if any signs of a diffuse distribution of peroxidase but displayed several pinocytotic vesicles and occasionally trans-endothelial channels filled with peroxidase, sometimes with a slight leakage of peroxidase into adjacent basement membranes and neuropil. Scattered pinocytotic vesicles were observed in capillaries and venules, but there was usually no extravasation of peroxidase around these vessels.
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  • 20
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    Acta neuropathologica 44 (1978), S. 147-149 
    ISSN: 1432-0533
    Keywords: Cadmium ; Endothelial cell ; Capillary ; Fetal brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pregnant rats received a single administration of 0.5, 1.0, or 2.0 mg/kg of cadmium on day 18 or 20 or gestation Maternal animals were killed on day 21 and samples of the caudate nucleus from fetal brains were examined using the transmission electron microscope. A 2.0 mg/kg dose of cadmium administered to maternal rats on day 20 of gestation caused the formation of vacuoles in the endothelial cells of capilaries in the fetal brain. Significant endothelial cell vacuolization was not observed in the brain of fetuses from other treatment groups. The vacuoles occurred singly, were spherical in shape, were located adjacent to the intercellular junctions and caused focal distortion of the endothelial cell. Vacuoles were the only ultrastructural alteration observed in the caudate nucleus of fetal brains.
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  • 21
    ISSN: 1432-0533
    Keywords: Protein-calorie malnutrition ; Rat ; Spinal root ; Sciatic nerve ; Internodal length
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The current investigation comprised normal young rats as well as rats submitted to a 50% food reduction or severe protein restriction. Isolated nerve fibres from lumbar spinal roots and sciatic nerves were investigated with reference to the relation between length and diameter of internodes as well as variation of internodal length along single nerve fibres. The present results do not support the view that protein-calorie malnutrition should cause neuropathy. Internodal segments were, on an average, shorter in relation to their thickness in young rats submitted to severe protein restriction or a 50% food reduction. The deviation was most marked in low-protein animals and particularly among coarser internodal segments. An inhibition of longitudinal growth was considered to be the main factor behind the difference between malnourished and normal rats.
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  • 22
    ISSN: 1432-0533
    Keywords: Experimental brain gliomas ; Chemically induced ; Rat ; Cell cultures ; Humoral antibodies ; Immunofluorescence staining ; Microcytotoxicity assay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Brain tumors were induced in Sprague-Dawley and Long-Evans rats by administration of N-methyl-N-nitrosourea in the drinking water. Of these tumors, a grade 2 mixed glioma, a grade 2 to 3 astrocytoma and a grade 1 to 2 oligodendroglioma were established in vitro, maintained in culture and designated 75SD-G-376, 75SD-G-420 and 77LE-G-180, respectively. Of these mass cultures, two were successfully cloned and are currently available as 75SD-G-376C and 75SD-420C cell lines. Clonal lines produce S-100 protein and grow as tumors when isografted in young rats. Using the cultured cells as target cells, specific antibodies were searched for in the sera of the rats with the primary tumors by means of an indirect fluorescent antibody staining method and a complement-dependent antibody-mediated microcytotoxicity assay. Fluorescent and cytotoxic antibodies were demonstrated in the sera of the mixed glioma- and astrocytoma-bearing animals. However, a variable proportion of cells of the 75SD-G-376 and 75SD-G-420 lines showed no reaction with the corresponding sera. Furthermore, cytotoxic anfibodies had a lytic effect on the autologous glioma cells only in the presence of rabbit complement.
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  • 23
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    Acta neuropathologica 44 (1978), S. 245-247 
    ISSN: 1432-0533
    Keywords: Schwann cells ; PNS myelin ; Retina ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Within the retinal nerve fiber layer of a 6-week-old Sprague-Dawley rat, scattered aggregates of PNS myelinated axons have been found and described. We believe this is likely to represent a normal but rare phenomenon in the rat.
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  • 24
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    Calcified tissue international 25 (1978), S. 75-83 
    ISSN: 1432-0827
    Keywords: Rat ; Fluorosis ; Enamel ; Scanning electron microscopy ; Low temperature incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Sixteen 58-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. These changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.
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  • 25
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    Naunyn-Schmiedeberg's archives of pharmacology 303 (1978), S. 165-170 
    ISSN: 1432-1912
    Keywords: Striatum ; Evoked potentials ; Neuroleptics ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The interaction of cortico- and nigrofugal inputs to the striatum of the rat was investigated using the technique of evoked potentials. Repetitive, unilateral stimulation of the substantia nigra inhibited potentials which were evoked from the ipsilateral rostral cortex and recorded from the ipsilateral striatum. The inhibition was antagonized by low doses of various intraperitoneally administered neuroleptics such as: pimozide (0.1–0.2 mg/kg), haloperidol (0.1–0.5 mg/kg), chlorpromazine (0.5–2.0 mg/kg) and thioridazine azine (0.5–4.0 mg/kg). These findings are discussed in view of the existing controversy regarding the mode of action of dopamine in the striatum.
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  • 26
    ISSN: 1432-2013
    Keywords: Oxygen dissociation curve ; Oxygen transport ; Cardiac output ; Coronary blood flow ; Blood flow to organs ; Hypoxia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A major displacement of the blood O2 dissociation curve (ODC) was achieved in rats by chronic administration of sodium cyanate (NaOCN). Control animals with a normal position of the ODC received NaCl instead. Arterial and mixed-venous O2 content ( $${\text{C}}_{{\text{O}}_{\text{2}} }$$ ) and O2 consumption were measured during breathing room air, 14.9, 8.0, or 5.6% O2 in N2. Cardiac output was obtained by the Fick principle.86RbCl was administered i.v., the rats were killed and the activity of86Rb in heart, spleen, stomach and intestines, liver, kidney, skeletal muscle, and skin was measured. According to Sapirstein (1956, 1958) the fractional uptake of86Rb in these organs corresponds to the fractions of cardiac output supplying these organs, and from the fractional uptake and cardiac output the nutritional blood flow may be calculated. Arterial and mixed-venous $${\text{C}}_{{\text{O}}_{\text{2}} }$$ was larger in the NaOCN than in the NaCl rats at all levels of oxygenation. At normoxia and 14.9% O2 the venous $${\text{C}}_{{\text{O}}_{\text{2}} }$$ was enlarged more than the arterial one, and so the arterio-venous O2 difference [ $$\left( {{\text{a}} - {\text{v}}} \right)_{{\text{O}}_{\text{2}} }$$ ] as an index of the O2 extraction in the body was smaller in the rats with a left-shifted ODC. However, at more severe hypoxia (8.0 and 5.6% O2) the arterial $${\text{C}}_{{\text{O}}_{\text{2}} }$$ in the NaOCN rats was enlarged more than the mixed-venous one, resulting in a larger $$\left( {{\text{a}} - {\text{v}}} \right)_{{\text{O}}_{\text{2}} }$$ (and therefore O2 extraction) when compared with the NaCl animals. Cardiac output was larger in the NaOCN than in the NaCl rats at 14.9 and 5.6% O2, when expressed per kg body weight. At 14.9% O2 the augmented cardiac output compensated for the lower O2 extraction when compared with the NaCl animals. At 5.6% O2 the NaOCN rats had both a larger ( $$\left( {{\text{a}} - {\text{v}}} \right)_{{\text{O}}_{\text{2}} }$$ ) and cardiac output than the NaCl animals. In the NaCl rats the decreased O2 extraction was not compensated for by an augmented cardiac output and therefore their O2 consumption was not only lower than that of the NaOCN rats but decreased even below the normoxic value of the NaCl rats. Coronary blood flow was increased in both NaOCN and NaCl animals at deep hypoxia to about the same extent, but due to a much lower arterial $${\text{C}}_{{\text{O}}_{\text{2}} }$$ of the NaCl animals, their O2 supply to the heart was lower than that of the NaOCN rats. The nutritional blood flow to spleen, kidney, liver, stomach and intestines, and skin in ml/min · g was lower in the rats with a normal position of the ODC than in those with a left-shifted ODC. This, together with the low arterial $${\text{C}}_{{\text{O}}_{\text{2}} }$$ of the NaCl rats, suggests a serious compromising of the O2 supply to these organs. Results of this study support the conclusion of our theoretical studies (Turek et al., 1973; Turek and Kreuzer, 1976) that a shift of the ODC to the left might be disadvantageous for the O2 transport to tissues at mild hypoxia, but advantageous at severe hypoxia.
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  • 27
    ISSN: 1432-2013
    Keywords: Blood gases ; Cardiac hypertrophy ; Intercapillary distance ; Myocardial infarction ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In rats with a myocardial infarction due to ligation of the left coronary artery a marked right ventricular hypertrophy developed after 41/2 weeks. At this time no difference against control animals was observed in arterial $$P_{{\text{O}}_2 }$$ , $$P_{{\text{CO}}_2 }$$ , pH, ideal alveolar $$P_{{\text{O}}_2 }$$ , and alveolar-arterial O2 pressure difference, as measured in unanesthetized animals at normoxia. In histological sections of the heart stained by PAS reaction capillaries and muscle fibers were counted, and the mean intercapillary distance and muscle fiber diameter were estimated. In the right ventricle of the rats with myocardial infarction both increased when compared with control animals or with sham-operated rats. Fibercapillary ratio was the same in all three groups. Similar results were obtained in the remaining undamaged tissue of the left ventricle of rats with a myocardial infarction when compared with the left ventricle of control or sham-operated rats. Findings concerning intercapillary distance suggest that also in the myocardium which remains intact during the development of the infarction and later hypertrophies, tissue oxygen transport might be impaired, particularly during a stress situation. Results in the right ventricle of rats with myocardial infarction show an opposite trend against rats exposed chronically to simulated high altitude, where in the hypertrophied right ventricle a shorter intercapillary distance occurs and therefore an improvement of tissue oxygen transport might be expected.
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  • 28
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    Pflügers Archiv 376 (1978), S. 245-249 
    ISSN: 1432-2013
    Keywords: Colon ; Amino acid uptake ; Basolateral membrane ; Active transport ; Sheep ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Uptake of the nonmetabolizable model amino acid 2-aminoisobutyric acid (=AIB) through the basolateral membrane into epithelial cells was studied in sheep colon stripped of serosa and muscle layers. Only the antiluminal surface of the mucosa was exposed to the incubation medium. Thus AIB entry into epithelial cells could only occur through the basolateral membrane. AIB was taken up by a saturable process against a high concentration gradient. AIB uptake was inhibited by other neutral amino acids but not by sugars. In a low Na+ medium AIB uptake was impaired, indicating that active transport of amino acids through the basolateral membrane of colon epithelial cells is Na+-dependent. In the rat a saturable concentrative uptake of AIB through the basolateral membrane of colon epithelial cells has also been demonstrated. Concentrative uptake of amino acids through the basolateral membranes is probably important for the supply of colon epithelium with amino acids.
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  • 29
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    Pflügers Archiv 373 (1978), S. 133-138 
    ISSN: 1432-2013
    Keywords: Deoxycholate ; Intestinal perfusion ; Rat ; Enzymatic release ; Localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The release of proteins, sucrase (SA), maltase (MA), leucine aminopeptidase (LA) and alkaline phosphatase (AP) activity from rat jejunum by sodium deoxycholate (DOC) was studied by an in vivo perfusion technique. In our experimental conditions, a 2 mmol/l DOC perfusion for 30 min induced a marked and reversible release of proteins and hydrolases. When specific activities were considered, each enzyme showed a distinct release pattern. Significantly, the SA release was largely increased, the AP release was decreased and there was no correlation between the releases of SA and AP. Furthermore, the various enzymes recovered into the lumen were solubilized at different extents. SA was chiefly present in a soluble and AP in a particular form. The microscopical appearances showed a slight exfoliation of the epithelial cells from the villous tips but no specific changes when compared to the control group. The results are discussed in terms of enzymic localization in the brush border membrane; SA would be located very superficially in the surface membrane and AP buried in the membrane and less accessible than the other enzymes.
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  • 30
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    Pflügers Archiv 374 (1978), S. 229-234 
    ISSN: 1432-2013
    Keywords: Cyclic AMP ; ADH ; Vasopressin ; Isoproterenol ; 3-isobutyl-1-methylxanthin ; Rat ; Water diuresis ; Antidiuresis ; Dehydration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In vivo experiments were performed in male Wistar rats to elucidate the probable relation between renal concentrating ability and medullary cyclic AMP content as influenced by changes of hydration and by administration of antidiuretic hormone (ADH). Cyclic AMP levels were 37% lower in water diuretic than in control animals (P〈0.01), but were not significantly changed during prolonged antidiuresis induced by dehydration or ADH administration. Nor could any change of cyclic AMP levels be demonstrated between 2 and 20 min after ADH injection. Significant increases of medullary cyclic AMP content occurred following stress, anesthesia, and administration of isoproterenol and 3-isobutyl-1-methylxanthin. The results suggest that the level of cyclic AMP in the renal medulla may not be an important determinant of the antidiuretic response produced by ADH in rats.
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  • 31
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    Pflügers Archiv 374 (1978), S. 285-288 
    ISSN: 1432-2013
    Keywords: High altitude ; Blood volume ; Red cell volume ; Plasma volume ; Body haematocrit ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Circulating blood volume (BV) as the sum of circulating red cell volume (RCV) and plasma volume (PV) was estimated in rats native to a simulated altitude of 3500 m (“natives”), in rats born at sea level and later in life transferred to the simulated high altitude (“newcomers”), and in control sea-level rats. RCV per kg body weight (b.w.) was significantly larger in both “newcomers” and “natives” than in controls. PV per kg b.w. was in the “newcomers” insignificantly and in the “natives” significantly smaller than in the controls. BV per kg b.w. in both high altitude groups tended to be larger than in controls but the difference was not significant. Arterial haematocrit (Ahct) in the “newcomers” was significantly higher than in the controls, and in the “natives” significantly higher than in both other groups. Body haematocrit (the ratio of RCV and BV in per cent) was smaller than Ahct in all groups; this was more pronounced in the “newcomers” than in the controls and even more so in the “natives”. Apparently the haematocrit in the minute vessels of the organs of animals exposed to chronic hypoxic hypoxia increases much less than might be expected from changes of the Ahct. An attempt was made to evaluate the possible error of the more commonly used method of estimating BV, when only RCV, or only PV, is measured, and BV and its complementary fraction are calculated from arterial or venous haematocrit. When, in our results, BV was calculated from RCV and Ahct, the absolute values and also the differences between groups were somewhat underestimated. When BV was calculated from PV and Ahct, the BV itself, and particularly the differences between groups, were overestimated quite considerably. It is suggested that the only safe way to estimate BV is to measure RCV and PV separately.
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  • 32
    ISSN: 1432-2013
    Keywords: PAH clearance ; PAH extraction ; Glomerular filtration rate ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract PAH secretion (TPAH) was studied in rats at spontaneously occurring glomerular filtration rate (GFR). At saturated transport, TPAH was found to be correlated to GFR. This relationship was also observed at unsaturated transport where TPAH depends upon the PAH concentration in arterial plasma. However, no significant correlation between TPAH and renal PAH load or renal plasma flow rate was found when the effects of GFR were removed by partial correlation analysis. A dependency of TPAH on GFR explains the correlations found between filtration fraction (FF) and renal PAH extraction (EPAH) or renal tubular PAH extraction fraction (EPAH-FFPAH). Thus, even at low PAH concentration in a. plasma, renal PAH extraction may only be assumed to be constant if the filtration fraction is constant.
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  • 33
    ISSN: 1432-2013
    Keywords: Oxygen dissociation curve ; Oxygen transport ; Blood gases ; Hypoxia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Theoretical deductions have shown that a shift of the blood O2 dissociation curve (ODC) to the right might improve O2 transport to tissues at normoxia and at mild hypoxia whereas at severe hypoxia the organism should be better off with an ODC shifted to the left (Turek et al., 1973b; Turek and Kreuzer, 1976). The present study was performed in order to ascertain this ambiguous effect of an ODC shift depending on the degree of hypoxia in intact animals. A major displacement of the ODC to the left was achieved in rats by chronic administration of sodium cyanate (NaOCN). Control animals received sodium chloride (NaCl) instead. Arterial and mixed-venous $$P_{{\text{O}}_{\text{2}} }$$ , $$P_{{\text{CO}}_{\text{2}} }$$ , and pH were measured at normoxia and during breathing 14.9, 8.0, or 5.6% O2 in N2 in both groups. From $$P_{{\text{O}}_{\text{2}} }$$ , pH, ODC and arterial hematocrit, arterial and mixed-venous O2 contents were estimated and $$({\text{a}} - {\text{v)}}_{{\text{O}}_{\text{2}} }$$ as an index of blood O2 extraction was obtained. At normoxia and during breathing 14.9% O2 the NaOCN rats had a lower mixed-venous $$P_{{\text{O}}_{\text{2}} }$$ than the NaCl rats without any difference in pH. Arterio-venous O2 difference did not differ at normoxia but was lower in NaOCN rats at 14.9% O2. However, at 8.0 and 5.6% O2 the NaOCN rats had a higher mixed-venous $$P_{{\text{O}}_{\text{2}} }$$ , an increased $$({\text{a}} - {\text{v)}}_{{\text{O}}_{\text{2}} }$$ , and a higher pH (arterial and mixed-venous). At 5.6% O2 the NaCl rats developed a severe acidosis concomitant with pronounced hypocapnia. These findings confirm that rats with a left-shifted ODC have an impaired O2 transport to tissues at normoxia and mild hypoxia but a more efficient O2 transport at severe hypoxia as compared with rats with an unshifted ODC, in agreement with our previous theoretical studies.
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  • 34
    ISSN: 1432-0738
    Keywords: Cadmium ; Drug Metabolism ; Metallothionein ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of acute and chronic cadmium administration on hepatic drug metabolism was investigated in the male rat. 3 days after the acute administration of cadmium by either the intraperitoneal (0.84 mg Cd/kg) or the oral (〉 80 mg Cd/kg) route, there was a significant potentiation in duration of hexobarbital hypnosis and inhibition of hepatic microsomal metabolism of hexobarbital and aniline. Administration of cadmium in the drinking water at levels of 100 or 200 ppm Cd for periods of 2–12 weeks or at levels of 5 or 20 ppm Cd for 50 weeks did not produce alterations in either drug response or hepatic drug metabolism. Significant levels of metallothionein, a cadmium binding protein, found in the liver of the rats receiving cadmium chronically may offer an explanation for the observed differences in drug metabolism between the acute and chronic administration of cadmium. In additional studies, pretreatment of the rats with subthreshold doses of cadmium (0.21 or 0.42 mg Cd/kg) intraperitoneally produced a tolerance to the alterations in drug metabolism induced by the previous cadmium dose (0.84 mg Cd/kg, i.p.). However, chronic cadmium treatment (5 or 20 ppm Cd for 50 weeks) did not impart any such tolerance to subsequently administered Cd (0.84 mg/kg) by the intraperitoneal route. The hepatic levels of metallothionein induced by the chronic cadmium treatment were only 30–60% of those induced by the subthreshold cadmium and thus may not have bound enough of the large challenge cadmium dose to produce the tolerance phenomenon.
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  • 35
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    Archives of toxicology 39 (1978), S. 267-287 
    ISSN: 1432-0738
    Keywords: Rat ; Plasma ; Alkaline phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report describes the application of a test system which applies different substrates, inhibitors and acrylamide electrophoresis to the study of the alkaline phosphatase activity of rats. The system, which was specifically devised to characterise the alkaline phosphatase activity of small quantities of plasma from rats in toxicological studies, was also used to examine the plasma from rats under several physiological conditions, e.g. time of day, age, diet, etc. These physiological factors can influence the measurement of plasma alkaline phosphatase activity and should be taken into account when designing toxicological studies. Different experimental regimes were used to produce increases in liver, bone and intestinal alkaline phosphatase isoenzymes in the plasma of rats and these were reflected in the characterisations by the system. Although much remains unknown, a few concepts of rat plasma alkaline phosphatase activity emerged under our conditions. There is a ‘tidal’ intestinal component which arises from feeding and is approximately 60% of the total activity of the fed rat. In the fasted rat this ‘tidal’ component has largely disappeared and the ‘core’ activity which remains is composed of approximately equal proportions of bone isoenzyme and another as yet ill-defined component. The liver isoenzyme which appears in the plasma of the cholestatic rat appears to be either a very minor component or absent from the plasma of our normal CFE derived rat.
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  • 36
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    Archives of toxicology 40 (1978), S. 7-16 
    ISSN: 1432-0738
    Keywords: Thallium ; Furosemide ; Acetazolamide ; Renal elimination ; Oral absorption ; 204Tl ; Kidney ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Im Rahmen einer Untersuchung über das Schicksal von Thallium im Organismus und über den Einfluß von Diuretika auf die Eliminationsgeschwindigkeit dieses Giftes wurde Tl2SO4 (48.9 μmol = 10 mg/kg) an wachen Ratten oral verabreicht. Die Blutspiegel von Tl+ wurden anschließend als Funktion der Zeit ermittelt, sie konnten mit einer klassischen Bateman-Funktion nicht richtig beschrieben werden. Etwa l Std nach oraler Verabreichung war die Blutkonzentration maximal. Die Behandlung mit Furosemid (30 mg/kg) beschleunigte die Entfernung von Thallium aus dem Organismus auf signifikante Weise. Etwa 35% der zugeführten Menge Thallium wurde während einer Woche nach der Injektion dieses Diuretikums mit dem Urin ausgeschieden. Auch die Ausscheidung von Natriumionen und Wasser war signifikant erhöht, die von Kaliumionen blieb jedoch fast unverändert. Thallium selbst verursachte eine schwache diuretische Wirkung. Nach fortgesetzter Behandlung mit Furosemid (bis 2 Wochen) blieb die Eliminationsgeschwindigkeit von Thallium, Wasser und Natrium beschleunigt, während die Ausscheidung von Kaliumionen im Vergleich zu Kontrolltieren etwas herabgesetzt war. Ethacrynsäure verursachte nach wiederholter Gabe in diuretisch wirksamen Dosen eine retroperitoneale Fibrose. Dieses wirksame Diuretikum konnte daher nicht in die Untersuchung einbezogen werden. Acetazolamid (30 mg/kg) erhöhte ebenfalls die Ausscheidung von Thallium, vor allem innerhalb der anfänglichen 24 Std. Die Wirkung war weniger intensiv als die von Furosemid, sie war außerdem bald erschöpft. Die Ergebnisse legen den Schluß nahe, Furosemid in hohen Dosen sei eine wirksame Maßnahme zur Beschleunigung der Thalliumentfernung aus dem Organismus, zumindest im vorliegenden Tiermodell. Acetazolamid ist zu diesem Zwecke wahrscheinlich nicht geeignet.
    Notes: Abstract In connection with a programme of investigations concerning the disposition of thallium in the rat and the influence of diuretic agents on the rate of elimination of thallium from the body, Tl2SO4 (48.9 μmol = 10 mg/kg) was given by mouth to conscious rats. Blood levels were studied as a function of time. They could not be described adequately by means of a classical Bateman function. The maximum blood level was achieved approximately 1 h following oral ingestion. Treatment with furosemide for 11 days (30 mg/kg twice daily) significantly accelerated the removal of thallium from the body with the urine. Approximately 35% of the administered thallium was excreted within one week following the injection of this diuretic agent. The excretion of sodium and water was also considerably enhanced, that of potassium hardly changed. Thallium itself displayed weak diuretic activity. Upon prolonged treatment (1–2 weeks) with furosemide the elimination of thallium, water and Na+ was still accelerated, although that of potassium proved diminished with respect to controls. Ethacrynic acid when administered repeatedly in appropriate doses caused retroperitoneal fibrosis. Therefore, this potent diuretic agent was not included in the investigations. Acetazolamide (30 mg/kg) also enhanced the excretion of thallium, especially within the initial 24 h of treatment. The effect was less pronounced than that of furosemide and rapidly exhausted. The results suggest that furosemide in a high dose is effective in accelerating thallium elimination from the body in the present animal model. Acetazolamide is probably not suitable for this purpose.
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  • 37
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    Archives of toxicology 41 (1978), S. 99-105 
    ISSN: 1432-0738
    Keywords: Rat ; Method ; Gastric ulceration ; Distention of stomach ; Stress ; Anti-inflammatory drugs ; Ulcerogenic side effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das sog. „distention“-Ulkus wurde an Albinoratten untersucht und als neue Möglichkeit für die Feststellung ulzerogener Nebenwirkungen von Substanzen beschrieben. Die Dehnung des Magens in sich war nicht ausreichend um ulzerogene Läsionen auszulösen, denn die Dehnung des Magens mit physiologischer Kochsalzlösung führte nicht zur Ulzeration. Die Säure ist ein entscheidender Faktor in der Bildung des „distention“-Ulkus. Große Volumina von 0,1 N Salzsäure riefen innerhalb von 1 Std massive Ulzeration hervor. Kleine Mengen von dieser Säurelösung verursachten keine Ulzeration im Magen. Entzündungshemmer, die in noch von ulzerogenen Nebenwirkungen freien therapeutischen Dosen verabreicht wurden, erhöhten die Empfindlichkeit der gastralen Mukosa dem aggressiven Faktor, der Säure, gegenüber. Bei den mit bekanntlich ulzerogen wirkenden Dosen von Entzündungshemmern vorbehandelten Ratten wurde eine schnellere Bildung von Ulzera durch die Dehnung des Magens mit Säure beobachtet. Auch die Stressvorbehandlung beschleunigte und verstärkte die Bildung der durch Dehnung hervorgerufenen ulzerogenen Veränderungen im Magen.
    Notes: Abstract A modification of the distention ulcer was studied in albino rats and a new possibility of testing ulcerogenic side effects of drugs was described. The distention alone was not sufficient to produce lesions. The severity of ulcer lesions was highly dependent on the volume of the acid solution. Large volumes of 0.1 N HCl evoked severe ulcers within 1 h. Small amounts of weak acid solution did not cause any ulceration. Anti-inflammatory drugs administered in therapeutic doses, which did not yet produce any ulcers in animals, increased the sensitivity of the gastric mucosa against the aggresive factor, the acid. In animals pretreated by anti-inflammatory drugs in toxic doses an earlier development of ulceration was observed by distention with acid. Stress also accelerated and aggravated the formation of distention ulcers.
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  • 38
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    Archives of toxicology 39 (1978), S. 249-266 
    ISSN: 1432-0738
    Keywords: Rat ; Alkaline phosphatase ; Plasma ; Organs ; Toxicity testing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A manual system of various estimations of rat plasma alkaline phosphatase activity has been devised for small volumes of plasma which uses different inhibitors, compares the utilisation of two substrates and includes acrylamide gel electrophoresis. The different inhibitors etc. allow a degree of discrimination between alkaline phosphatase extracts of rat organs. The properties of isoenzymes, e.g. intestinal alkaline phosphatase, differ depending upon the environment in which they are studied. In conjunction, if necessary, with the methods described for the estimation of liver and intestinal alkaline phosphatase activity, it is hoped to use the system to discriminate between the isoenzymes present in the plasma alkaline phosphatase of rats in toxicological studies.
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  • 39
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    Journal of cancer research and clinical oncology 91 (1978), S. 157-164 
    ISSN: 1432-1335
    Keywords: MNU ; DNA Repair ; Rat ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary DNA repair time-course was studied after injury by N-methyl-N-nitrosourea (MNU) in rat liver cells of animals of different ages and in fetuses using hydroxyurea (HU) as inhibitor of scheduled DNA synthesis. DNA repair was a rapid phenomenon, more so in young adults than in newborns, and was not detectable in fetuses. A correlation seems to exist among organ sensitivity to carcinogen, age of animal and DNA repair.
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  • 40
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    Journal of molecular medicine 56 (1978), S. 309-310 
    ISSN: 1432-1440
    Keywords: Perhexilin-Maleat ; generalisierte Lipidose ; Ratte ; Perhexiline maleate ; Generalized lipidosis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Administration of perhexiline (Pexide®) to rats causes generalized occurrence of lamellated and crystalloid cytoplasmic inclusions which resemble those described in patients with perhexiline-induced polyneuropathy. It is concluded that perhexiline being an amphiphilic cationic compound is a potent inducer of generalized lipidosis.
    Notes: Zusammenfassung Perhexilin (Pexid®) verursacht bei der Ratte das generalisierte Auftreten von lamellären und kristalloiden zytoplasmatischen Einschlußkörpern, die denjenigen gleichen, die bei Patienten mit Perhexilin-induzierter Polyneuropathie beschrieben worden sind. Aus den vorgelegten Befunden wird geschlossen, daß Perhexilin, eine amphiphile kationische Verbindung, ein starker Induktor einer generalisierten Lipidose ist.
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  • 41
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    Naunyn-Schmiedeberg's archives of pharmacology 302 (1978), S. 239-254 
    ISSN: 1432-1912
    Keywords: Myocardial α-adrenoceptors ; Rat ; Guinea pig ; Cat ; Hypothyroidism ; Single adrenoceptor type
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The presence and distribution of myocardial α-adrenoceptors in different parts of the heart of various mammalian species was investigated. For this reason experiments were performed in isolated cardiac preparations of rats, guinea pigs and cats. In order to obtain more information about the nature of the cardiac α-adrenoceptors additional experiments were undertaken at different temperatures. These studies were aimed to show whether or not a conversion of β-to α-adrenoceptors or vice versa takes place. Moreover, we analyzed the influence of hypothyroidism on the sensitivity of α- and β-adrenoceptors of preparations from rats fed with propylthiouracil. Finally, we tried to find out whether stimulation of these α-adrenoceptors leads to the formation of the cyclic nucleotides cAMP and cGMP. The following results were obtained: 1. In right ventricular strips of rats, guinea pigs and cats phenylephrine stimulated α-adrenoceptors. After blockade of β-adrenoceptors the respective pD2-values of phenylephrine were 5.32, 5.99 and 5.33. The doseresponse curves obtained in the presence of α-adrenolytic drugs were shifted to the right without depression of the maximum. In the rat, in addition, the pA2-values for the α-adrenolytic drugs yohimbine (5.79) and phentolamine (7.85) were determined. They were at least 0.5 log units higher than those found in the rat for other α-adrenoceptors (Van Rossum, 1965) thus supporting the view that the population of cardiac α-adrenoceptors is different from that of other organs. In left ventricular strips of guinea pigs the pD2-value for the α-mimetic effect of phenylephrine was of the same order of magnitude as that obtained in the right ventricle. 2. In the papillary muscle of the right ventricle of guinea pigs and cats phenylephrine stimulated α-adrenoceptors. 3. In the left atrium of the rat, phenylephrine stimulated myocardial α-adrenoceptors (pD2: 5.58). Also in this preparation the pA2-values for yohimbine (6.36) and phentolamine (8.21) were different from those found for other α-adrenoceptors in the rat (Van Rossum, 1965). Likewise in strips from the left atrium of the cat myocardial α-adrenoceptors are present. 4. In spontaneously beating right atria of the rat a clear-cut positive chronotropic effect mediated by stimulation of α-adrenoceptors could not be demonstrated although in 6 out of 15 preparations a small positive chronotropic effect became evident. No positive chronotropic effect at all was obtained by stimulation of α-adrenoceptors in the cat right atrium. 5. In ventricular strips as well as in left atria from hypothyroid rats the pD2-value for the α-effect of phenylephrine was increased, in the atrium more than in the ventricle, while the pA2-values for yohimbine and phentolamine were not significantly different from the controls. Under these conditions a distinct positive chronotropic effect mediated by stimulation of α-receptors was found in the spontaneously beating rat atrium. 6. After stimulation of α-adrenoceptors in atria and ventricular strips of normal and propylthiouraciltreated rats, as well as in strips of guinea-pig ventricles or cat atria no elevation of cAMP and cGMP was observed. 7. The concept of a single adrenoceptor convertible from α- to β-type or vice versa was not supported by our experiments. These were carried out at different temperatures on left atria and on ventricular strips of rat hearts using the irreversible α-adrenoceptor blocking agent phenoxybenzamine. 8. The present experiments provide evidence for the existence of α-adrenoceptors in the myocardium of various mammalian species. Their stimulation produces positive inotropic effects without increases in heart rate.
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  • 42
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    Naunyn-Schmiedeberg's archives of pharmacology 303 (1978), S. 251-256 
    ISSN: 1432-1912
    Keywords: Diurnal rhythm ; Motor activity ; Rat ; H 44/68 ; FLA 63 ; Animex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of the inhibitor of the tyrosine-hydroxylase H 44/68 and the inhibitor of the dopamine-β-hydroxylase FLA 63 on the diurnal variations of the motor activity was studied in male Wistar rats, which were kept under standardized conditions of light and darkness (L:D=12:12h). The motor activity was continuously registered in groups of 5 rats using a two-channel Animex motimeter. During light FLA 63 (40 mg/kg, s.c.) greatly increased motor activity on acute application and during darkness the physiological elevation in motor activity was further but slightly increased. H 44/68 (200 mg/kg, i.p.) also increased motor activity during light, but in contrast to FLA 63 greatly reduced motor activity during darkness. The results indicate that though dopamine and noradrenaline are involved in the regulation of behavioural components, one or the other catecholamine may play a predominant role at different times of the day. Thus, it seems worthwhile to study the effects of drugs separately during light and during darkness.
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  • 43
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    Naunyn-Schmiedeberg's archives of pharmacology 303 (1978), S. 257-261 
    ISSN: 1432-1912
    Keywords: Diurnal rhythm ; Central noradrenaline and dopamine turnover ; H 44/68 ; FLA 63 ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Under controlled conditions of environmental light and darkness of 12:12 h the turnover of dopamine and noradrenaline in brain of male Wistar rats was studied at different times of the day. The turnover was calculated from the decline of the amine concentrations either after inhibition of the tyrosine-hydroxylase with H 44/68 (200 mg/kg, i.p.) or after inhibition of the dopamine-β-hydroxylase with FLA 63 (40 mg/kg s.c.). Whereas the noradrenaline turnover showed only slight but not significant variations within 24 h, the turnover of the central dopamine exhibited significant variations with increased turnover rates in the second half of the light and first half of the dark period. Thus, diurnal variations have to be taken into account when studying the effects of drugs on the turnover of biogenic amines in the central nervous system.
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  • 44
    ISSN: 1432-1912
    Keywords: Gastric secretion ; Cyclic AMP ; Phosphodiesterase inhibitor ; Rat ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of the phosphodiesterase inhibitor 4-(3-cyclopentyloxy-4-methoxyphenyl)-2-pyrrolidone (ZK 62711) on gastric secretion and the cyclic AMP system of the gastric mucosa was studied in rats and guinea pigs. In rats, 0.03–0.3 μmoles/kg ZK 62711 i.v. stimulated acid and pepsin secretion in a dose-dependent manner and 0.03 μmoles/kg i.v. enhanced the effect of histamine. In guinea pigs no reproducible stimulation was found after intravenous injections of ZK 62711. The stimulation of gastric secretion in the rat by 0.3 μmoles/kg ZK 62711 i.v. was not affected by vagotomy but was totally inhibited by 10 μmoles/kg cimetidine i.v. The structurally related phosphodiesterase inhibitor, 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidine (Ro 20-1724), at the dose of 3.3 μmoles/kg i.v. stimulated gastric secretion in anaesthetised rats to a similar extent as 0.3 μmoles/kg ZK 62711 i.v. The content of cyclic AMP in the rat gastric mucosa in vivo was slightly increased by 10 μmoles/kg ZK 62711 i.v, whereas lower doses did not change it. Accumulation of cyclic AMP in the rat gastric mucosa by 50 μmoles/kg histamine i.v. was enhanced by simultaneous injections of 3.3 μmoles/kg ZK 62711 i.v. In rat gastric tissue slices in vitro 1–50 μM ZK 62711 increased the level of cyclic AMP but 100 μM histamine had no effect in the absence or presence of ZK 62711. In gastric mucosal slices of the guinea pig 10 and 50 μM ZK 62711 increased the cyclic AMP content which effect was inhibited by 100 μM cimetidine and enhanced the stimulatory effect of 100 μM histamine on cyclic AMP. The activity of soluble cyclic AMP phosphodiesterase was inhibited by ZK 62711 in the rat (IC50=18 μM) and guinea pig gastric mucosa (IC50=1.5 μM). Adenylate cyclase was not affected in the homogenate of the guinea pig gastric mucosa. The results indicate that the phosphodiesterase inhibitor ZK 62711 which increases cyclic AMP levels in the gastric mucosa in vivo and in vitro, is a potent stimulator of gastric acid secretion.
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  • 45
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    Cell & tissue research 189 (1978), S. 155-166 
    ISSN: 1432-0878
    Keywords: Levator ani muscle ; Rat ; Neuromuscular junction ; Castration ; Testosterone effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the neuromuscular junction (n.m.j.) of the androgen-sensitive levator ani muscle was studied in normal adult male rats, in 8-month-old rats castrated at the age of one month and in castrated rats treated with testosterone propionate (TP). Castration does not result in significant changes of the n.m.j. The density of synaptic vesicles and the postsynaptic junctional folds remain practically normal in spite of marked atrophy of the muscle. TP administration for 7 days results in marked changes in preand postsynaptic structures. There is slow progressive depletion of synaptic vesicles, appearance of cisternae and coated vesicles in axon terminals, and coalescence of coated vesicles with the plasma membrane. Coated vesicles are also found inside Schwann cells and among junctional folds. Dense core vesicles appear both in the axon terminals and in the postsynaptic area. Collateral sprouting of terminal axons with the formation of new immature junctions is observed. After 35 days of TP administration depletion of synaptic vesicles continues. Glycogen β-particles, mostly freely dispersed, occasionally seen in axon terminals 7 days after TP administration, subsequently increase in number. In the endplate zone of the muscle fibre increased protein synthesis is indicated by a rapid increase in ribosomes and irregularly located myofilaments and myofibrils. The appearance of n.m.j. after testosterone administration resembles that described after nerve stimulation; the degree of change is however less pronounced.
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  • 46
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    Cell & tissue research 189 (1978), S. 277-286 
    ISSN: 1432-0878
    Keywords: Maternal adrenalectomy ; Rat ; Influence on the adrenals of newborn animals ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Maternal adrenalectomy at 7 or 14 days of gestation produced increased cell necrosis within zona reticularis cells on the day of birth and at 24 or 48 h after birth. Small remnants or large portions of adrenocortical cells were present within macrophages. In otherwise normal adrenocortical cells, lipid droplets were incorporated within some mitochondria. Autophagocytosis of single mitochondria was observed within adrenocortical cells. Undoubtedly ultrastructural changes represent stimulation of adrenocortical cells in neonatal rats in response to maternal adrenalectomy.
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  • 47
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    Cell & tissue research 191 (1978), S. 501-506 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Ultrastructure ; Perivascular space ; Hormonerelease ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes from rats subjected to neurohypophysial hormone-releasing stimuli were examined electron microscopically following fixation in 4 % tannic acid in 2.5 % glutaraldehyde. This fixation allowed the delineation of the perivascular space in the neural lobe tissue. Measurement of the area of the perivascular space showed that it was significantly increased in the rats subjected to vagal stimulation and intraarterial calcium ions compared to the control rats. The rats which had been subjected to haemorrhage as a hormonereleasing stimulus did not show any significant change in the area of the perivascular space. The significance of these findings in relation to hormone release is discussed.
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  • 48
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    Cell & tissue research 191 (1978), S. 507-512 
    ISSN: 1432-0878
    Keywords: Odontoblasts ; Osteoblasts ; Cementoblasts ; Intercellular attachments ; Electron microscopy (SEM/TEM) ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osteoblasts of the young rat cranium, and cementoblasts and odontoblasts of young rat molars were prepared by ethanol freeze-fracture prior to critical point drying for scanning electron microscopy (SEM) as well as conventional transmission electron microscopy (TEM) techniques. Critical point drying causes shrinkage which separates the lateral intercellular contacts between neighbours in the same sheet in the case of cementoblasts and osteoblasts, but not those between odontoblasts. These differences are considered to be of functional significance and need to be taken into consideration when formulating theories of calcium influx into the mineralizable matrix of the respective tissues.
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  • 49
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    Cell & tissue research 191 (1978), S. 513-523 
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Freeze-fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nerve terminals in the palisade zone of the rat median eminence were investigated with freeze-fracture electron microscopy. Fracture face P of the specific terminals showed two populations of intramembranous particles (IMP): a large and a small variety. The large IMP-s often formed small irregular clusters. In nerve terminals the total number of both populations of IMP-s was considerably less than that found on P membrane faces of ependymal feet. On fracture face E of the nerve terminals, the number of IMP-s was about a quarter of that seen on fracture face P. On both fracture faces of most terminals a few small round impressions (or elevations respectively) were found which may be interpreted as broken necks of either exo- or endocytotic vesicles. Neither gap nor tight junctions occurred at lateral membranes of the specific axon terminals. Similarly, no membrane specializations were observed with freeze-fracturing on membrane areas adjacent to the basement membrane. The findings are discussed in relation to a possible exocytosis mechanism of the hypothalamic releasing and inhibiting hormones.
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  • 50
    ISSN: 1432-0878
    Keywords: Taste buds ; Circumvallate papillae ; Colchicine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It is believed that differentiation and maintenance of taste buds in vertebrates is dependent on the trophic function of their sensory nerve supply. In the present work colchicine was injected into the circumvallate papilla of the rat. This produced a reversible blockade of neuroplasmic transport and disappearance of taste buds. Colchicine inhibited the further differentiation of bud cells, but apparently did not change the life cycle of the cells present already at the time of injection. It is speculated that the neurotrophic factors in this particular cell system are effective to induce cell differentiation only.
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  • 51
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    Cell & tissue research 188 (1978), S. 345-359 
    ISSN: 1432-0878
    Keywords: Hippocampal subfields ; Rat ; Volumes ; Timm stain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The absolute volumes of the hippocampal and subicular cortical layers in the rat were determined. The boundaries of the various layers were defined on series of sections made through the entire hippocampal region of five rats and stained according to the Timm sulfide silver technique. Coordinates representing the boundaries of the layers on selected sections were fed into a mini-computer programmed to calculate the volume of the layers from the areas of the profiles and the distances between the sections. The distribution of the layers indicates that they constitute the same proportion of the volume of the dorsal and ventral divisions of the hippocampal region, with the exception of the structures lying in regio inferior and regio superior. Although the combined regio superior and regio inferior components of the layers of Ammon's horn occupy the same percentage of the volume of the dorsal and ventral hippocampal regions, the regio superior components occupy a larger percentage of Ammon's horn in the dorsal region than they do in the ventral region. The inter-animal variations in the volumes of the various layers indicate that it is possible to describe quantitatively the subdivisions of the hippocampal region with a precision that is compatible with comparative studies.
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  • 52
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    Cell & tissue research 188 (1978), S. 491-496 
    ISSN: 1432-0878
    Keywords: Castration ; LH-cells ; Rat ; Development ; Sex-steroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of sex-steroids on the LH-cell development in neonatal rats were studied. The cells were stained immunohistochemically by applying anti-HCG serum. On the second day after birth some of the animals of both sexes were gonadectomized and simultaneously injected with testosterone or estradiol (50 or 200 μg). The remaining animals were either gonadectomized or injected with either one of the sex-steroids. The LH-cell numbers in each group were determined on the 12th day of age from serially cut histological sections of the pituitary. In castrated males the number of LH-cells was about twice that of the intact animals. In the so-called sex-zone, LH-cells tended to be hypertrophied in castrates. These alterations in the appearance of LH-cells did not occur after ovariectomy. In gonadectomized animals injected with sexsteroids (200 μg), the cells were markedly reduced in number and size, both in males and females. Testosterone injection (50 μg) into intact newborn animals also suppressed the numerical development of LH-cells, especially in females. These alterations were particularly evident in the sex-zone in both sexes. Thus the present findings show that sex-steroids may be involved in sexual differences in morphological development of LH-cells in newborn rats.
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  • 53
    ISSN: 1432-0878
    Keywords: Adrenal gland ; Rat ; Vinblastine ; Corticosterone ; Exocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vinblastine treatment blocks corticosterone release from rat adrenal zona fasciculata without impairing hormone synthesis, and induces the formation of acid phosphatase-positive granular clumps at the juxta-sinusoidal pole of the cells. Autoradiography shows that ACTH administration to vinblastine-treated animals mobilizes the 3H-cholesterol stored in the lipid droplets and leads to a noticeable labelling of the granular clumps. The possible significance of these granules is discussed.
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  • 54
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    Cell & tissue research 188 (1978), S. 285-297 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Rat ; Organ culture ; Indole metabolism ; Ultrastructural morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In vitro indole metabolism and ultrastructural morphology of the pineal gland of male rats were examined. A comparison of the effect of norepinephrine stimulation on indole synthesis in whole cultured glands and preparations of dispersed pineal cells is discussed. Our studies on the performance of dispersed cells during the first 24 h after preparation indicate a strong dependence of pineal cells upon physical attachment to the culture dish and probably also on cell-to-cell contact.
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  • 55
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    Cell & tissue research 192 (1978), S. 285-297 
    ISSN: 1432-0878
    Keywords: Intestinal epithelium ; Rat ; Kinetics ; Autonomic denervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of autonomic denervation upon the kinetics of the ileal epithelium of rats was studied by tracing 3H-thymidine labelled nuclei and counting mitotic figures and goblet cells. Counts of labelled nuclei and goblet cells provided information about cell migration along the intestinal epithelium. The mitotic index and turnover time of this population were calculated from the mitotic figures counts. Comparing denervated animals with sham operated controls, it was possible to conclude that autonomic denervation, either sympathectomy or parasympathectomy results in a decrease in mitotic activity. As a result of lower mitotic activity in the crypts, the turnover time increases and there is a delay in the migration of cells from the crypts towards the villi. Sympathectomy causes an early short-lived effect upon the kinetics of the crypt cell population, since after 27 h there is a tendency to normality. Parasympathectomy produces a slower but continuous decline in mitotic activity.
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  • 56
    ISSN: 1439-6327
    Keywords: Exercise ; Altitude ; Left ventricular work ; Myocardial blood flow ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Total hemodynamic values and left ventricular blood flow were studied using Sapirstein's method of 86Rb uptake in female rats 24 h after a last exposure to high altitude. A simulated altitude of 1350 m was used, initial exposure being for 30 min, gradually increased by 30 min daily up to 330 min daily for 5 days a week; the total number of exposures was 32. In another animal group the hypobaric exposure was combined with swimming in water at 37
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  • 57
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    European archives of oto-rhino-laryngology and head & neck 220 (1978), S. 201-212 
    ISSN: 1434-4726
    Keywords: Plica vocalis ; Epithelial surface ; Rat ; Extrapulmonary airway epithelium ; Scanning electron microscopy ; Stimmbänder ; Epitheliale Oberfläche ; Ratte ; Larynxepithel ; Rasterelektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Stimmbandepithel ausgewachsener männlicher Albinoratten wird rasterelektronenmikroskopisch untersucht. Seine Oberflächenstruktur wird mit jener des Epithels auf der Plica ventricularis und im Recessus ventricularis verglichen. Charakteristischerweise zeigen die Zellen im Epithel über den Stimmbändern einen dichten, lückenlosen Besatz mit Mikrovilli. Die Übergänge des Stimmbandepithels in die benachbarten Larynxabschnitte wird dokumentiert. Besondere Aufmerksamkeit wird dem Auftreten von Mikroleisten auf den apikalen Zellpolen im Larynxepithel gewidmet, die bisher als charakteristische Struktur für das Stimmbandepithel gewertet wurden.
    Notes: Summary The epithelial surface of the Plica vocalis in adult male rat is studied by scanning electron microscopy. It's structure is compared with that of the plica and of the recessus ventricularis. The transition of the epithelium in the plica vocalis to the epithelium of the joining parts of the larynx is documented. Special attention is paid to the occurrence of microridges at the apical poles of epithelial cells in the larynx. Up to now microridge cells have been said to be characteristic for the plica vocalis.
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  • 58
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    Cell & tissue research 190 (1978), S. 61-68 
    ISSN: 1432-0878
    Keywords: Oogonia and M-prospermatogonia ; Rat ; Duration of the S-phase and the minimal generation time ; Comparative autoradiographic studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Bei der Ratte tritt die letzte Generation der Oogonien und “multiplying prospermatogonia” (M-prospermatogonia), die häufig in Form synchronisierter “Cluster” angeordnet sind, um den Tag 17 post conceptionem (p.c.), in die Mitose. Die S-Phasen-Dauer D-S-Duration und die minimale Generationszeit T min der weiblichen und männlichen “Gonien” wurden nach der Methode der markierten Mitosen bestimmt (22 weibliche und 22 männliche Feten von 11 Muttertieren wurden 2–22 Std nach einmaliger i.p. Injektion mit 3H-thymidin getötet). Die drei Kurven markierter Prophasen, Metaphasen und der postmitotischen Abkömmlinge, d.h. der Postmitosephasen der Oocyten und primary transitional prospermatogonia” (T1-prospermatogonia), wurden ausgewertet. Die Auswertungen ergaben, daß der Verlauf der einander entsprechenden Markierungskurven von Prophasen, Metaphasen und Postmitosephasen sowie die daraus errechneten Werte für D-S-Duration und Tmin weitgehend übereinstimmen. Die gewonnenen Werte liegen zwischen 10 und 12,5h für D-S-Duration (10h entsprechend dem Verlauf der markierten Metaphasenkurven) und 16,5 und 18h für Tmin (16,5h entsprechend dem Verlauf der markierten Metaphasenkurven).
    Notes: Summary In the rat the last generation of oogonia and multiplying prospermatogonia (M-prospermatogonia), frequently arranged in synchronized clusters, enters mitosis on about day 17 post conception (p.c.). The duration of the S-phase D-S-Duration and the minimal generation time T min of both kinds of “gonia” were determined by the method of labeled mitoses (22 female and 22 male fetuses derived from 11 pregnant rats were sacrificed from 2 to 22 h after a single i.p. injection of 3H-thymidine on day 17 p.c.). Three curves, derived from the labeled prophases, metaphases and the postmitotic descendents of oogonia and M-prospermatogonia — oocytes and primary transitional prospermatogonia (T1-prospermatogonia) — were evaluated. It was demonstrated that the curves as well as the calculated values of D-S-Duration and T min are very similar for oogonia and M-prospermatogonia. D-S-Duration ranged from about 10 to 12.5 h (10 h read off from the curves of labeled metaphases), T min from 16.5 to 18 h (16.5 h read off from the curves of labeled metaphases).
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  • 59
    ISSN: 1432-0878
    Keywords: Nucl. n. facialis ; Rat ; Retrograde reaction ; Ontogenesis ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The grey level index (= GLI) and the fresh volume were determined with the image analyser Micro-Videomat for the nucl. n. facialis after axotomy of the left n. facialis. The experiments were performed on 10 rats in different stages of ontogenesis. The GLI is a quantitative parameter which could be quickly obtained and which demonstrated quantitative changes during retrograde reaction in the respective centres. A decrease in the fresh volumes of the affected nucl. n. facialis could also be demonstrated. The meaning of GLI is discussed.
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  • 60
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    Cell & tissue research 190 (1978), S. 349-355 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Striated musculature ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In a total of 96 rat pineals studied 31 were found to contain striated muscle fibers or their precursors. The muscle fibers were most frequently present in the stalk region and more frequently found in the left than in the right hemisphere. Size measurements revealed that the lengths of pineal muscle cell nuclei differ only slightly from those of the sphincter muscle of the iris. However, the yellowish appearance of pineal muscle cell nuclei under darkfield investigation, a phenomenon observed in all muscular tissues of mesenchymal origin and connective tissue cells, may support the hypothesis that pineal musculature is of mesenchymal rather than ectodermal origin.
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  • 61
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    Cell & tissue research 193 (1978), S. 315-322 
    ISSN: 1432-0878
    Keywords: Intranuclear inclusions ; Pericytes ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This paper deals with the ultrastructure of two types of intranuclear inclusions, “nuclear bodies” and “membranous lamellar bodies”, present in hypothalamic pericytes of intact adult rats. The nuclear bodies exhibited “simple” and “granular” forms, whereas the membranous lamellar bodies were entirely made up of myelin-like membrane whorls. The occurrence of these bodies in nuclei of pericytes has never been previously reported. The origin and functional meaning of such structures is discussed in the light of recent ultrastructural and biochemical studies on nuclear inclusions.
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  • 62
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    Cell & tissue research 194 (1978), S. 163-170 
    ISSN: 1432-0878
    Keywords: Cell kinetics ; Enamel organ ; Cell production ; Cell cycle ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The inner enamel epithelium (IEE) covers the labial tooth aspect as a one cell layer which, when cut sagittally, appears as a longitudinal cell column extending from the tooth origin toward the periphery. Following sudden tooth shortening, the IEE responds by an increased cell production which later declines below normal values. The perturbation affects all cell kinetic parameters; the progenitor compartment, which initially increases, diminishes in size toward end of the experiment. The cell cycle transition times, which initially decline, rise toward the end of the experiment. The mean normal daily cell production rate of 70 cell % (i.e. 70 cells are produced by 100 progenitors) increases to 111 cell % and then declines to a low of 51 cell %. The IEE response typifies the behavior of other cell renewal systems such as intestinal epithelium and epidermis.
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  • 63
    ISSN: 1432-0878
    Keywords: LHRH neuron ; Tissue culture ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ontogenetic development of LHRH-containing neurons was studied by fluorescence and enzyme immunohistochemistry in rats. In in vitro studies, the tissues of the septal-chiasmatic and mediobasal hypothalamic areas of fetal rats on day 16.5 or 18.5 of gestation were trypsinized separately for dissociation of the neural cells, and cultured for several days. Immunopositive reaction against LHRH was first detected in nerve cells derived from both areas of the hypothalamus of the fetuses on days 16.5 and 18.5 of gestation, after 8 and 6 days culture, respectively. The cells were small, and seemed to be bipolar in morphology indicating an axon and arborized dendrites. Immunopositive material occurred in the cell soma as well as in the cellular processes. In in vivo studies, immunopositive material, possibly deposited in nerve fibers, appeared first in OVLT and simultaneously in the external layer of the median eminence of fetuses on day 20.5 of gestation. The immunoreactive fibers increased in number in both parts with development, especially after birth in the median eminence. No immunopositive material was detected within any neural cell bodies nor in the cytoplasm of any ependymal cells.
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  • 64
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    Cell & tissue research 195 (1978), S. 499-513 
    ISSN: 1432-0878
    Keywords: Somatostatin neurons ; Hypothalamic, extrahypothalamic distribution ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using a highly sensitive antibody to somatostatin, its hypothalamic and extrahypothalamic distribution in the rat was re-examined by light microscopic immunohistochemistry (PAP-method). The scattered somatostatin-producing perikarya occur in multiple layers within the subependymal neuropil surrounding the third ventricle. They supply with short-distance projections the following hypothalamic nuclei: 1) preoptic nuclei (especially their suprachiasmatic and medial components), 2) the peripheral zones of the suprachiasmatic nuclei, 3) the ventromedial and 4) arcuate nuclei, and 5) the ventral premammillary nuclei. Furthermore, the following long-distance projections have been observed: In a rostral direction (A1) rostral of the anterior commissure to the lamina terminalis, (A2) to the OVLT, (A3) to the olfactory tubercle, and (A4) rostrally and caudally by-passing the anterior commissure to the dorsal part of the stria terminalis. More caudally, at the retrochiasmatic level an ascending dorso-lateral projection joins the ventral amygdalo-hypothalamic pathway in a reciprocal manner (B1). In addition, a descending ventrolateral tract projects to the optic tract bending dorsal to it in different directions: (C1) medial to the median eminence, (C2) lateral to the corticomedial amygdala, and (C3) caudal for additional support of the arcuate and ventral premammillary nuclei. The principal tract of somatostatin-containing fibers descends in the subependymal neuropil to the median eminence (D). The results are discussed with reference to a possible participation of the somatostatin fiber system in the afferent branch of the circuit connecting the hypothalamus with the amygdala via the stria terminalis.
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  • 65
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    Cell & tissue research 190 (1978), S. 181-185 
    ISSN: 1432-0878
    Keywords: Vitamin A ; Ultimobranchial tissue ; Ultimobranchial cysts ; Thyroid ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultimobranchial cysts in the thyroid glands of rats receiving a diet adequate in vitamin A are lined with stratified squamous epithelium and contain non-keratinized cellular debris. The epithelium of these cysts in vitamin A deficient animals is keratinized, and their lumina contain keratinized cellular strands surrounding a core of cellular debris. Upon return to a diet adequate in vitamin A the epithelium returns to a non-keratinized state, and the lumina contain keratinized strands surrounded by cell fragments and desquamated whole cells. Occasionally these cysts have an epithelium that is highly irregular in appearance. The relationship of alterations in this tisssue to possible subsequent development of neoplasias is discussed.
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  • 66
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    Cell & tissue research 191 (1978), S. 183-186 
    ISSN: 1432-0878
    Keywords: Amygdaloid body ; Hypothalamus ; Midbrain ; Autoradiography ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light microscopic autoradiography was performed subsequent to injection of tritiated amino acids into various parts of the amygdaloid body of the rat. Evidence is provided for two hitherto unreported projections of the amygdala: from the medial amygdaloid nucleus to the contralateral premamillary nuclei and from the central amygdaloid nucleus to the mesencephalic central grey. The functional implications of these findings are discussed.
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  • 67
    ISSN: 1432-0878
    Keywords: Taste bud ; Vallate papilla ; Regeneration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The regeneration of the vallate papilla in the rat was studied by both light and electron microscopy. The papillae were excised and regeneration was studied at time intervals of 3 to 45 days. It was found that the vallate papilla is capable of regeneration after both partial and total papillectomies. The regenerated papillae were asymmetrical in shape. Several invaginations, independent of one another, were the equivalent of the original sulcus. Regeneration of the gustatory system occurred at circumscribed portions of the associated Von Ebner glands. The amounts of newly formed taste buds were proportional to the amount of nerve fibers in the subepithelial plexus. The regenerated taste buds showed normal histochemical and fine-structural characteristics. The results support the contention of some degree of specificity concerning the epithelium where taste bud regeneration occurs.
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  • 68
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    Cell & tissue research 193 (1978), S. 525-532 
    ISSN: 1432-0878
    Keywords: Intranuclear inclusions ; Neurons ; Development ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of intranuclear rodlets, microtubules, fibrillar lattices and membranous inclusions found in the developing cuneate nuclei of rats is described. Rodlets, ranging in diameter from 96–312 nm and in length from 1–2 μm, are made up of tightly packed straight filaments measuring 5–8 nm in diameter. Microtubules with a diameter of 26 nm are clustered together. Fibrillar lattices are made up of fibrils with a diameter of 9 nm arranged in layers or sets. Two to nine sets make up a lattice, with a maximum width of 68 nm, in which the adjacent sets are arranged at an angle to each other. Rodlets and fibrillar lattices occur in 6.8% of the neurons. Membranous inclusions, reported here for the first time in normal neurons, are of 2 types: small vesicles of 0.1–0.6 μm and large vacuoles measuring 1–2 μm. Both types are bounded by either a single or a double membrane and generally have an electron lucent content. Membranous inclusions occur in 25.3 % of the neurons. Changes in the frequency of occurrence of the various intranuclear inclusions in the course of postnatal development are also reported.
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  • 69
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    Cell & tissue research 194 (1978), S. 17-35 
    ISSN: 1432-0878
    Keywords: Synapses ; Optic nerve ; Suprachiasmatic nucleus ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Synapses of optic nerve afferents (optic synapses) in the rat suprachiasmatic nucleus (SCN) have been identified ultrastructurally. They are easily distinguished from other types of synapses. The optic boutons are characterized by the presence of large mitochondria with a swollen electron lucent matrix and an interconnected tubular system formed by their inner membrane. Other, more variable features include: 1) a scattered pattern of synaptic vesicles which are found throughout the entire presynaptic element with relatively little accumulation near the active zones; 2) the occurrence of dense core vesicles and glycogen granules; 3) the active zones, the majority of which is Gray-type I, but a minority can obviously be classified as Gray's type II; 4) the innervation of smaller peripheral dendrites and dendritic spines. Boutons of this kind are exclusively filled with anterogradely transported horseradish peroxidase injected into both eyes. Very few neuronal elements containing the typical mitochondria have been observed in the SCN on the 6th day post partum, increasingly more on the 9th and 12th day, but considerably higher numbers after opening of the eyes on the 17th and the following days. The location of normal and degenerating optic boutons was examined light- and electron microscopically. In the rostral third of the SCN there are relatively few optic synapses which are found close to the optic chiasma. In the middle portion of the SCN optic synapses increase in number; they are found not only in the ventral part of the nucleus but also in lateral regions. This becomes particularly obvious in the caudal third of the SCN.
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    Cell & tissue research 194 (1978), S. 353-359 
    ISSN: 1432-0878
    Keywords: Intranuclear microfilament bundles ; Third ventricle ; Ependymal cells ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Intranuclear microfilament bundles were observed in ependymal cells of the third ventricle of the rat. They appeared as single, cylindricallyshaped fibrillar bands up to 4.9 μm in length. In cross sections of bundles, the microfilaments exhibited an apparently regular arrangement. They were separated by a distance of 4 to 5 nm, measuring approximately 11 nm from centre to centre. One bundle consisted of 55 to 88 microfilaments. The intranuclear bundles terminated at the inner membrane of the nucleus. They exhibited close spatial relationship to perinuclear chromatin, chromatin centres, intrachromatin granules and fibrillar structures. The average ratio of nuclear sections with and without bundles was 1∶15.
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  • 71
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    Cell & tissue research 195 (1978), S. 145-152 
    ISSN: 1432-0878
    Keywords: Spinal cord ; Axonal degeneration ; Reactive microglia ; Capsaicin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Capsaicin treatment of newborn rats results in the degeneration of primary sensory neurones involved in the mediation of chemogenic pain. In the present study glial changes following the pharmacologically-induced degeneration of unmyelinated primary afferent fibres terminating in Rexed's laminae I and II of the spinal cord were investigated. Light microscopy revealed an increase in the number of phagocytic glial cells in this area, reaching a maximum at 24 h after the administration of capsaicin; they had almost completely disappeared by 72 h. At the ultrastructural level these cells were characterized by their elongate or irregular nuclei with a pronounced heterochromatin pattern, a moderately dense cytoplasmic matrix, hour-glass shaped mitochondria and very large numbers of heterogeneous dense bodies and lipid droplets. On the basis of these observations, these cells were considered to represent reactive microglial cells engaged in the phagocytosis of degenerated neuronal debris. The possible origin and mode of elimination of these elements from the central nervous tissue is briefly discussed.
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  • 72
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    Cell & tissue research 195 (1978), S. 359-366 
    ISSN: 1432-0878
    Keywords: Calcareous concretions ; Pineal gland ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Serial sections of 90 Sprague-Dawley rat brains with the pineal in situ were scanned to determine the occurrence and regional distribution of calcareous concretions within the pineal gland and its surrounding leptomeningeal tissue. In 90 % of the cases examined concretions were found in varying number and appearance, predominantly lying in the dorsal region of the pineal gland and in the distal portion of the pineal stalk. Discussing the hypothesis advanced by Lukaszyk and Reiter (1975) that the origin of pineal concretions may be related to a neurosecretory process involving a pineal carrier protein, called neuroepiphysin, it is thought that, in view of the intra- and extra-pineal occurrence of concretions, processes other than secretion should be considered. Since in the pineal organ lymphatics are lacking it may well be that, due to a reduced drainage of tissue fluid, the coagulation of intercellular organic debris mingled with minerals increases with age.
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  • 73
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    Anatomy and embryology 131 (1970), S. 236-242 
    ISSN: 1432-0568
    Keywords: Cartilage ; Ear, external ; Differentiation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The differentiation of cartilage in the external ear of the rat proceeds in four steps. Each of them is characterized by a specific biosynthetic activity of the chondroblast resulting in the appearance of a new structural component of the tissue: collagen fibrils, elastin fibers, cartilage ground substance and intracellular fat droplets. As a structurally and developmentally well-defined “subspecies” of cartilage, this tissue might serve as a suitable object for the experimental approach to some essential problems in histodifferentiation.
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  • 74
    ISSN: 1432-0568
    Keywords: Rat ; Early development ; Jolk-sac entoderm ; Reichert's membrane ; Trophoblast-cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Rattenkeime des Schwangerschaftstages 7–10 wurden elektronenmikroskopisch untersucht. Das viscerale einschichtige Dottersackentoderm zeichnet sich durch eine ausgeprägte endocytotische Aktivität aus. Die Zellen des parietalen Blattes dagegen liegen isoliert der Reichertschen Membran innen an und enthalten vorwiegend rauhes endoplasmatisches Reticulum. Die Reichertsche Membran besteht aus einem lockeren Maschengitter feiner Filamente. Im antimesometrialen und lateralen Bereich haften nur wenige Trophoblastenzellen dieser Membran von außen an, dazwischen befinden sich weite Lücken. Zum mütterlichen Gewebe hin wird der Keim mit Ausnahme des mesometrialen Poles von einem bis zu 50 μ breiten periembryonalen Sinus umgeben, der mütterliches Blut enthält. Nach außen wird dieser Raum durch Trophoblasten- und Deciduazellen abgedichtet. Aus diesen Befunden wird geschlossen: 1. Die Reichertsche Membran wird vom parietalen Dottersack-Entoderm gebildet. 2. Mütterliches Blutplasma kann frei das viscerale Dottersack-Entoderm erreichen, da als einzige kontinuierliche Schicht zwischen Blut und Träger nur die weitmaschige Reichertsche Membran vorhanden ist. 3. Durch das endocytotische und lysosomale System des visceralen Dottersackentoderms wird das anströmende mütterliche Plasma aufgenommen, abgebaut und für den wachsenden Keim nutzbar gemacht. 4. Immunbiologisch betrachtet können Antikörper der Mutter den Keim erreichen. 5. Embryonale Antigene dagegen erreichen durch die Errichtung einer Deciduabarriere nicht den mütterlichen Kreislauf. 6. Der periembryonale Sinus stellt einen Blindsack dar, in den zwar mütterliches Blut einströmen kann, ein Ausstrom aber nicht mehr möglich ist.
    Notes: Summary Electron microscope studies of rat embryos were performed from the 7th to 10th days of pregnancy. The single-layered visceral yolk entoderm is characterized by a marked endocytotic activity. The cells of the parietal layer lie separately adjacent to the Reichert's membrane and they contain mainly rough endoplasmic reticulum. The Reichert's membrane consists of a loose network of fine filaments. In the antimesometrial and lateral sites only few trophoblast cells are seen to be attached to the membrane. Between them we find large gaps. With the exception of the mesometrial pole, the embryo is surrounded by a periembryonal sinus, 10–50 μ wide, which contains maternal blood. This sinus space is sealed tightly (zonulae occludentes) by trophoblast and decidual cells. From these findings it was concluded: 1. Reichert's membrane is formed from the parietal jolk sac entoderm. 2. The porous Reichert's membrane permits the maternal plasma to reach freely the visceral jolk sac entoderm. This membrane is the only continuous layer between blood and egg cylinder. 3. By the endocytotic and lysosomal system, the visceral jolk sac entoderm absorbs the plasma coming from the mother. This plasma is degraded and used for the growing embryo. 4. From the immunobiological point of view the antibodies from the mother can reach the embryo freely, 5. The embryonal antigens cannot reach the maternal circulation because of the presence of a decidual barrier, 6. The perimebryonal sinuses are blind sacs into which the maternal blood can flood but it cannot return.
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  • 75
    ISSN: 1432-0533
    Keywords: Ependyma ; Thiobarbiturate ; Rat ; Hypothalamus ; III. Ventricle ; Narcosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An 14 männlichen Ratten wurde nach langdauernder intraperitonealer Narkose mit Thiobarbiturat Veränderungen des Ependyms im III. Ventrikel festgestellt. In der Gegend über dem Nucleus ventromedialis und Nucleus dorsomedialis hypothalami lassen sich zwei Formen des Ependyms unterschieden: 1. ein einschichtiges hohes Ependym mit runden großen Zellkernen, 2. ein mehrreihiges flaches Ependym mit schmalen, ovalen Zellkernen. Das flache Ependym zeigt folgende Veränderungen: Farbdichte und die Menge des färbbaren Materials im Kern nehmen zu, die Kernmembran ist gefaltet, der Kern zeigt Zeichen der Schrumpfung und Pyknose. Die Kontrollgruppe wurde mit Curare behandelt. Eine statistische Sicherung erbrachte einen signifikanten Unterschied mit einer Irrtumswahrscheinlichkeit von 0,5‰.
    Notes: Summary Alterations in the ependyma of the third ventricle were caused by continuous intraperitoneal thiobarbiturate narcosis in14 male rats. In the region of the nucleus dorsomedialis and ventromedialis hypothalami two kinds of ependyma can be distinguished, 1. a simple cuboidal ependyma with a large rounded nucleus, and 2. a stratified squamous ependyma with a slender oval nucleus. The squamous ependyma shows the following changes. The depth of staining and the chromatin material of the nucleus increases, the membrane of the nucleus is folded, the nucleus shows the signs of shrinkage and pyknosos. The control group was treatened with Curare. The significant difference of the results encloses 0.5‰ probability of error.
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    Experimental brain research 11 (1970), S. 93-110 
    ISSN: 1432-1106
    Keywords: Auditory evoked potentials ; Sleep ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Click-evoked potentials were recorded from the rat's auditory cortex (AC), medial geniculate body (MGB), reticular formation (RF), and hippocampus (HIPP) during natural sleep and waking. Various amplitude measurements made on sliding averages by a computer provided essentially continuous measurement of evoked responses in long experiments. Changes in AC responses were simplest in potentials recorded from a depth of 1.0–1.5 mm, all components of the average waveform being larger during slow-wave sleep (SS) than in waking (W) and low-voltage fast sleep (LVFS). More complex changes in cortical surface responses included increases in the first positive wave, in a second positive deflection, and in a late negative wave during drowsiness (D) and SS. The second positive wave remained large during LVFS, while the late negativity changed form and peaked earlier. Early components of both surface and deep responses were not consistently different in W and LVFS. The only clear change in MGB responses was a reduction in amplitude during LVFS. Late positive waves in RF and HIPP responses were large during SS and small during W and LVFS. In general, increases in the very late components of responses at all sites distinguished periods of cortical synchrony from periods of cortical activation. The first negative deflection and a succeeding positive wave in the HIPP response were markedly increased during arousal.
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    Experimental brain research 11 (1970), S. 392-410 
    ISSN: 1432-1106
    Keywords: Subcellular fractionation ; Axons ; Synaptosomes ; Whole brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Subfractionation of a standard “synaptosome” fraction from whole brain has yielded two lighter layers rich in axonal segments devoid of synaptosomes similar to those obtained from cerebellar homogenates. The heavier layers were found to contain both synaptosomes and axonal segments plus a significant population of synaptosomes with axons attached. Quantitative studies of the percent perimeter of external membrane contributed by the various elements within the subfractions showed that the major constituents in decreasing order were axonal segments, synaptosomes, membranes of undetermined origin and free mitochondria. These findings have revealed that “synaptosome” preparations are more heterogeneous than previously reported and at the same time have indicated the possibility of future studies on axonal preparations from whole brain. Correlated biochemical data strongly suggest chemical differences in fractions rich in axonal segments in contrast to those enriched in synaptosomes.
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    Naunyn-Schmiedeberg's archives of pharmacology 265 (1970), S. 425-441 
    ISSN: 1432-1912
    Keywords: Intestinal Blood Flow ; Water Absorption ; Solute Absorption ; Jejunum ; Rat ; Darmdurchblutung ; Wasserresorption ; Salzresorption ; Jejunum ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The lumen of jejunal loops in rats anaesthetised with urethane were perfused with hypo-, iso- and hypertonic ringer, mannitol or glucose ringer solution. The blood flow (venous outflow), water, solute and glucose net flux were measured in the loop. 2. Lowering the blood flow from 1 ml/min/g wet tissue to 0.2–0.3 ml/min/g caused the solute and glucose net flux to decrease; the water net flux (positive or negative) was also decreased if non-isotonie solutions were used, but remained unchanged when isotonic solutions were perfused. 3. When the blood flow was raised from 0.2–0.3 ml/min/g to 1 ml/min/g the net flux of glucose, solute and water usually remained low. Using hypotonic solutions the water net flux changed to negative values, that is, fluid was passing into the lumen. 4. The influenee of intestinal blood flow on water, solute and glueose absorption can be referred to 3 factors: a) drainage by blood, b) inhibition of active transport mechanisms by anoxia during low blood flow, and c) damage to the villi as a result of insufficient blood flow.
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    Naunyn-Schmiedeberg's archives of pharmacology 265 (1970), S. 474-475 
    ISSN: 1432-1912
    Keywords: Trifluoroacetic Acid ; Trifluoroacetate ; Rat ; Liver Weight ; TrifluoressigsÄure ; Trifluoroacetat ; Ratte ; Lebergewicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The influence of trifluoroacetic acid (TFAA) and sodium trifluoroacetate (TFA) on the liver weight to body weight ratio was measured in rats by two methods. When TFA or TFAA were added to the drinking water at a concentrate of 1 Normal, rats became dehydrated and a slight increase in the ratio was noted after ten days. However, when these substances were administered to rats (1 ml per day) by gastric intubation no change in the ratio was noted after eight days.
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  • 80
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    Psychopharmacology 16 (1970), S. 369-374 
    ISSN: 1432-2072
    Keywords: Noradrenaline ; Intraventricular Injection ; Rat ; Behaviour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The behavioural effects of NA injected without narcosis into the lateral brain ventricle of the rats were studied with two different techniques. Rats were classified according their normal level of exploratory activity into three groups: high, medium and low. It was shown that NA in a dose of 10 μg increased locomotor activity only in animals of low activity; a dose of 50 μg increased locomotor activity in all the animals; and a dose of 200 μg induced a complete abolition of locomotor activity and a stuporose syndrome lasting 2 hours. The evidence that NA in some experimental conditions increases locomotor activity of rats supports the hypothesis that NA regulates processes in the central nervous system which stimulate behaviour.
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  • 81
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    Psychopharmacology 17 (1970), S. 198-202 
    ISSN: 1432-2072
    Keywords: Nicotinamide Adenine Dinucleotide ; Variable Interval Schedule ; Sidman Avoidance ; Sedative Effects ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of nicotinamide adenine dinucleotide (NAD) upon the response rates in variable interval and Sidman Avoidance schedules was studied in rats. Bar pressing on the variable interval reinforcement schedule was significantly reduced during the 15 min following the administration of 10 mg/kg i.p. and during the 60 min following the administration of 30 mg/kg NAD. Response rates on the Sidman Avoidance schedule were significantly reduced during the 60 min following the administration of 100 mg/kg NAD.
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    Psychopharmacology 18 (1970), S. 300-304 
    ISSN: 1432-2072
    Keywords: Rat ; Swimming Endurance ; Nicotine ; Tobacco Alkaloids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The swimming endurance of rats in a water tub was measured until the animals submerged for two seconds under the water surface. The total alkaloid fraction extracted from cigarette smoke produced deterioration of performance in doses of 0.05 to 0.2 mg/kg, whereas pure nicotine (0.1 and 0.2 mg/kg), as well as nicotine pretreated analogously to the extraction process of the total alkaloids produced performance improvements.
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    Experimental brain research 11 (1970), S. 515-527 
    ISSN: 1432-1106
    Keywords: Visual pathway ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following unilateral retinal destruction in rats the existence of a direct retinohypothalamic pathway was investigated using the Nauta and the Fink-Heimer methods. Critical analysis of the Fink-Heimer stained sections of the experimental animals suggests that fibres leaving the optic pathway pass to various hypothalamic nuclei: 1. Fibres from the dorsorostral part of the chiasm pass through the lamina terminalis and appear to end in the preoptic and anterior hypothalamic nuclei. 2. Fibres leaving the ventrocaudal border of the chiasm and optic tract pass to the arcuate and ventromedial hypothalamic nuclei. 3. From the dorsocaudal part of the chiasm fibres pass to the suprachiasmatic and ventromedial hypothalamic nuclei. 4. From the caudal part of the inferior bundle of the accessory optic tract fibres pass to the premamillary ventral nucleus. The amount of apparently terminal degeneration in the preoptic, anterior hypothalamic, suprachiasmatic and premamillary nuclei was small. Heavier terminal degeneration appears to be present in the arcuate and ventromedial hypothalamic nuclei.
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    Experimental brain research 11 (1970), S. 528-538 
    ISSN: 1432-1106
    Keywords: Visual pathway ; Hypothalamus ; Arcuate nucleus ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Degenerating nerve fibres and boutons were searched with the aid of the electron microscope in the arcuate nucleus of rats 2–7 days after bilateral destruction of the retina. In the arcuate nucleus of the control animals as well as in the operated animals, 4 types of boutons were distinguished on the basis of vesicular contents and glial ensheathment. In the operated animals changes interpreted as degenerating were found in small myelinated axons and boutons of type II (boutons containing both synaptic and granular vesicles). The changes were similar to those described in the literature as the “dark” type of degeneration in experimentally interrupted axons and boutons. Similar changes were not found in the unoperated animals. The conclusion is reached, that a small number of fibres of the optic tract reach the arcuate nucleus to terminate here.
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  • 85
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    Archives of toxicology 26 (1970), S. 203-209 
    ISSN: 1432-0738
    Keywords: Mercury ; Enteral Absorption ; Neutron Activation Analysis ; Rat ; Quecksilber ; enterale Resorption ; Neutronenaktivierungs analyse ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Durch Neutronenaktivierungsanalyse wird nachgewiesen, daß bei der Eatte von symptomlos vertragenem metallischem Quecksilber, oral zugeführt, ein geringer Anteil resorbiert wird, welcher zu einer Erhöhung der Queeksilberwerte in Blut und Niere auf reichlich das 10fache der Norm führt.
    Notes: Summary It was demonstrated by means of neutron activation analysis that a small portion of orally administered metallic mercury is absorbed by rats. The animals tolerated this without visible symptoms, yet it resulted in a 10-fold or greater increase above normal values of mercury in blood and kidneys.
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  • 86
    ISSN: 1432-2013
    Keywords: Renin ; Angiotensin ; Electrolytes ; Kidney Slices ; Rat ; Renin ; Angiotensin ; Elektrolyte ; Nierenschnitte ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Nierenschnitte von Wistarratten wurden in NaCl-Lösungen oder in Ringer-Bicarbonat(bzw. Phosphat-)-Puffern mit 0,1 g Glucose/l für 2 Std bei 37° C aerob inkubiert. 0,1 ml Medium wurde mit 1,9 ml Rinder-Reninsubstratlösung in Anwesenheit von Diisopropylfluorophosphat und EDTA bei pH 5,7 und 37° C für 2 Std inkubiert. Der Angiotensingehalt des Inkubates wurde im Blutdrucktest der Ratte bestimmt. In verschieden konzentrierten NaCl-Lösungen nimmt die Reninabgabe von 150–67 m Val/l (Na+) kontinuierlich ab. Auch in Ringer-Lösungen mit abnehmender NaCl-Konzentration und konstanter Konzentration der übrigen Elektrolyte findet sich zwischen 120 und 50 m Val/l (Na+) ein steiler Abfall der Reninabgabe. Bei Konstanterhaltung der Osmolarität durch zunehmenden Ersatz des NaCl durch Cholinchlorid oder Mannit vermindert sich die Steilheit der (Na+)-Abhängigkeit der Reninabgabe. Ersatz des NaCl im Bicarbonatpuffer durch verschiedene Konzentrationen von NaBr ergibt die gleichen Befunde wie mit NaCl. Bei vollständigem Ersatz des NaCl im Puffer durch verschiedene Konzentrationen von Chlolinchorid oder Mannit ist die Konzentrationsabhängigkeit der Reninabgabe weniger deutlich, bei Ersatz durch KCl nicht mehr signifikant. Die (Na+)-Abhängigkeit der Reninabgabe aus Nierenschnitten scheint nicht vom aeroben Stoffwechsel abhängig zu sein.
    Notes: Summary Rat kidney slices were incubated in saline solutions or in Ringer-bicarbonate (resp. phosphate-)-buffers containing 0.1 g/l glucose for 2 hrs at 37° C. Subsequently, 0.1 ml of the medium was incubated with 1.9 ml of ox renin-substrate solution, pH 5.7, for 2 hrs at 37° C in the presence of diisopropylfluorophosphate and EDTA. The angiotensin formed was measured by rat blood pressure assay. Renin release from kidney slices decreases markedly in NaCl-solutions between Na+-concentrations of 150 meq/l and 67 meq/l. Renin release decreases likewise in modified Ringer-solutions containing decreasing amounts of NaCl or NaBr (between 120 meq/l and 50 meq/l Na+), when the concentrations of other electrolytes are held constant. The (Na+)-dependence of renin release is less marked when the osmolarity of the medium is held constant by stepwise substitution of NaCl cholinchloride. Complete substitution of NaCl by different concentrations of cholin-chloride or mannitol diminishes the dependence of renin release on the osmolarity of the medium. Variation of KCl-concentration in the absence of NaCl does not influence renin release significantly. The (Na+)-dependence of renin release does not seem to depend on aerobic conditions.
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  • 87
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    Psychopharmacology 17 (1970), S. 234-241 
    ISSN: 1432-2072
    Keywords: Specific Inhibition of Amine Synthesis ; Brain ; DMI and RO 4-1284 Antagonism ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The influence of α-methyl tyrosine and diethyldithiocarbamate which specifically inhibit noradrenaline synthesis and the influence of p-chlorophenylalanine which inhibits 5-hydroxytryptamine synthesis in the brain on the antagonism between desmethylimipramine and RO 4-1284 was studied. It was shown that both substances which inhibit noradrenaline synthesis abolish the behavioural antagonism between DMI and RO 4-1284, and p-chlorophenylalanine is without effect on this antagonism. The evidence shows that DMI antagonises the action of a benzoquinolizine derivative by the participation of adrenergic mechanisms.
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  • 88
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    Psychopharmacology 17 (1970), S. 289-301 
    ISSN: 1432-2072
    Keywords: Scopolamine ; Hippocampus ; Activity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To test the hypothesis that the hippocampus may be an important site of action for anticholinergic drugs, scopolamine was administered to rats with hippocampal lesions produced by aspiration and to appropriate control groups, and their activity measured. The experimental design was a four-way analysis of variance with three lesion groups, three drug levels, eight measurements in a two-hour session, and four weeks. At the two higher drug doses (0.20 and 1.0 mg/kg), rats with hippocampal or cortical lesions had significantly greater activity than the sham operates (p〈0.01 and p〈0.05, respectively). A group of Ss with electrolytic hippocampal lesions tested at 0.20 mg/kg scopolamine had transitory activity increases. Therefore the hippocampus is not necessary for the motor activating effects of the drug nor is its ablation unique in producing increases in drug-induced activity.
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  • 89
    ISSN: 1432-2072
    Keywords: Rat ; Avoidance ; Extinction ; Nicotine ; Tobacco Alkaloids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of nicotine and total alkaloids extracted from smoke on the avoidance behavior of rats under extinction procedure has been measured in an experiment extended over a period of three months. There was no significant difference between the two substances, with both inhibiting the extinction of avoidance response to approximately the same degree. Significance against the control was achieved with all treatments, the effect being significantly greater with the dose of 0.2 mg/kg than with the two doses of 0.1 or 0.05 mg/kg.
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  • 90
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    Naunyn-Schmiedeberg's archives of pharmacology 266 (1970), S. 195-198 
    ISSN: 1432-1912
    Keywords: Rat ; Testis ; Semen ; Ejaculation ; Pharmacological Tests
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Each of 12 rats was eleetroejaculated 15 times. The semen plug was liquefied in 1% alpha-chymotrypsin, enabling the spermatozoa to be counted. Spermatozoa counts averaged 7,700,000 per ejaculate with a wide range. In 5 of the animals the coagulating glands and the seminal vesicles were surgically removed. After the removal of the glands the rats were electroejaculated 10 times. The still partly coagulated semen was dissolved in 1% alpha-chymotrypsin. The total ejaculate now showed a mean count of 18,600,000 spermatozoa with only a small range. By counting and comparing the number of spermatozoa in the ejaculate in treated and untreated rats with seminal vesicles and coagulating glands removed the effect of drugs on the testes can be examined.
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  • 91
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    Cell & tissue research 110 (1970), S. 97-107 
    ISSN: 1432-0878
    Keywords: Muscle Spindles ; Different types of sensory endings ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung In einer Muskelspindel der Ratte, die an einer Serie alternierender Semidünn- und Ultradünnquerschnitte untersucht wurde, wurden zwei benachbart an „nuclear chain“-Fasern gelegene Nervenendformationen unterschiedlicher Bauweise festgestellt. Die beiden Endformationen sind mit ein und derselben Nervenfaser der Gruppe II verbunden und daher als Bestandteile einer sekundären sensorischen Endigung zu betrachten. Die Nervenendformation an einer der beiden „nuclear chain“-Fasern hat anulo-spirale Form. Die Nervenendformation an der anderen „nuclear chain“-Faser weist am Querschnittsbild eine Anzahl von Axonen auf, die zwischen Plasmalemm und Basalmembran der intrafusalen Muskelfaser eng aneinanderliegen. Nicht alle Axonquerschnitte stehen in direktem Kontakt mit der intrafusalen Faser. Das terminale Axon scheint sieh nach Eintritt unter die Basalmembran der intrafusalen Faser mehrfach in relativ dünne Äste unregelmäßigen Verlaufs zu teilen. Diese Form der Endigung könnte ein Korrelat der sog. „flower spray“-Endigung im Sinne Ruffinis (1898) darstellen. Die beiden morphologisch unterschiedlichen Endformationen innerhalb der sekundären Endigung gleichen einander und den Endformationen der primären Endigung bezüglich folgender Ultrastrukturmerkmale: 1. Es besteht synaptischer Kontakt zwischen Axon und intrafusaler Muskelfaser (synaptischer Spalt durchschnittlich 200 Å) ohne Zwischenlagerung von Basalmembranmaterial; 2. die terminalen Axonabschnitte liegen direkt unter der Basalmembran der intrafusalen Muskelfaser und sind nicht von Schwannschen Zellen bedeckt; 3. Mangel an synaptischen Bläschen; 4. desmosomenartige Verhaftungen zwischen Zellmembranen von Axon und intrafusaler Faser; 5. dyadenartige Anlagerungen des sarkoplasmatischen Retikulums an die Zellmembran der intrafusalen Faser im Bereich des synaptischen Spaltes. Nach unseren derzeitigen Vorstellungen sprechen diese Ultrastrukturmerkmale für eine rezeptorische Natur der beschriebenen Nervenendigungen.
    Notes: Summary In a rat muscle spindle transversally cut into a series of alternating semithin and ultrathin sections, two different forms of nerve terminations were found on two neighbouring nuclear chain fibres. The two nerve terminations were connected to the same group II nerve fibre and are consequently constituents of one particular secondary sensory ending. The nerve termination on one of the two nuclear chain fibres is of the anulo-spiral type. The nerve termination on the second nuclear chain fibre shows a number of axons lying closely together between plasma membrane and basement membrane of the intrafusal muscle fibre. Not all of these axons are in direct contact with the intrafusal fibre. The terminating nerve fibre seems to be divided into several branches of rather small diameters and irregular courses. It is suggested that this kind of termination could be a correlate of the so-called “flower spray” type of sensory endings in muscle spindles. The two morphologically different nerve terminations in the secondary ending have the following ultrastructural characteristics in common with those of the primary ending: 1) Synaptic contact between axon and intrafusal muscle fibre (synaptic gap about 200 Å) without interposition of basement membrane material; 2) terminal axons located beneath the basement membrane layer of intrafusal muscle fibres without covering by Schwann cells; 3) lack of synaptic vesicles; 4) desmosome-like structures between plasma membranes of axon and intrafusal muscle fibre, and 5) dyads of the sarcoplasmic reticulum adjacent to the synaptic cleft. According to present knowledge these features indicate that all of these endings are sensory ones.
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  • 92
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Vasopressin release ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Le lobe postérieur de l'hypophyse a été examiné sur coupes ultrafines chez 45 rats (24 normaux, 17 déshydratés respectivement 1, 2 et 4 jours, et 4 anesthésiés à l'éther), après fixation au glutaraldéhyde ou selon la méthode de Karnovsky, post-fixation osmiée et double contraste à l'acétate d'uranyle et au citrate de plomb. Des fibres neurosécrétoires sombres et claires sont reconnaissables, mais les données manquent encore pour interpréter cette différence. Des densifications juxta-membranaires sont observées dans les terminaisons neurosécrétoires là où se trouvent des amas de microvésicules. Des fibres neurosécrétoires traversent parfois des pituicytes; il est aussi souvent observé des fibres, chargées de granules, libres dans un espace péricapillaire. Les espaces péricapillaires, ramifiés en tous sens loin des vaisseaux, développent une large surface de contact avec les extrémités nerveuses et les prolongements de pituicytes. Dans des conditions techniques bien contrôlées, la déshydratation n'entraîne pas de modifications appréciables des granules de neurosécrétat après 24 h. Ensuite les granules sont diminués en nombre, de façon très considérable le 4e jour; mais les granules restants ont un contenu dense normal; jamais il n'a été observé d'aspects de ≪granules vides ≫. Après anesthésie prolongée à l'éther, il n'y a aucune modification visible ni du nombre, ni de la densité des granules. Ces observations sont discutées quant au mécanisme de l'excrétion de vasopressine; elles sont en faveur de l'existence de deux pools hormonaux, l'un libre et rapidement disponible, l'autre plus fortement lié et certainement contenu dans les granules jouant le rôle de réserve. Toutefois un mécanisme d'exocytose granulaire ne peut être formellement exclu.
    Notes: Summary Hypophysial neural lobes of 45 rats (24 controls, 17 dehydrated resp. 1, 2 and 4 days, and 4 ether anesthetized) were fixed either with glutaraldehyde or according to Karnovsky and post-fixed in osmium tetroxyde; ultrathin sections were stained by uranyl acetate and lead citrate. Dark and clear neurosecretory fibres were observed, but sufficient data are still lacking for a valuable interpretation of these aspects. Juxta-membraneous densifications are visible in limited areas of neurosecretory terminals where clusters of microvesicles are present. Neurosecretory fibres happen to be completely encircled by pituioyte cytoplasm; fibres loaded with elementary granules are frequently encountered running free in a pericapillary space. Pericapillary spaces stretch out branching far away from vessels, resulting in a widespread contact with nerve terminals and pituicyte processes. In accurately controlled technical conditions, dehydratation does not result in any noticeable change of neurosecretory granules after 24 h. A decrease of the number of granules follows and is extremely conspicuous after 4 days; though, remaining granules keep a normal dense content, and aspects of “empty granules” have never been observed. After prolonged ether anesthesia, no visible change either in number or electron density of granules was observed. These findings are discussed in consideration of the mechanism of vasopressin release; they support the hypothesis of two hormonal pools, one of which would be free and rapidly available for release, the other being more tightly bound and certainly located in granules representing a storage site. Though granular exocytosis cannot be absolutely excluded.
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    Cell & tissue research 109 (1970), S. 384-397 
    ISSN: 1432-0878
    Keywords: Heart muscle cells ; Electron microscopy ; Quantitative ; Asphyxia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Normale und hypoxische Herzmuskelzellen aus der Wand des linken Ventrikels der Ratte wurden quantitativ-morphologisch anhand von elektronenmikroskopischen Längsschnitten nach Perfusionsfixierung untersucht. In normalen Zellen waren alle Myofibrillen relaxiert, die mittlere Sarcomerlänge betrug 2,2 μm. Die Schnittfläche wurde zu 55% von Myofibrillen, zu 27% von Mitochondrien und zu 18% von Grundplasma und Reticulum eingenommen. Die zwischen den Myofibrillen liegenden Mitochondrien waren längsoval und im Mittel 2,3mal so lang wie breit. Es bestand kein Unterschied zwischen subendokardial und subepikardial gelegenen Zellen. 10 min nach Erstickung der Tiere waren in den sonst unauffälligen Muskelzellen die Glycogengranula vermindert. Nach 20 min führte die Hypoxie zu einer Zunahme der relativen Schnittfläche der Mitochondrien um etwa 16% und zu einer beginnenden Kontraktur der Myofibrillen (Sarcomerlänge 2,0 μm). 20 min Hypoxie in Hypothermie (25–30°C intrathorakal) veränderte die normale Zellstruktur dagegen kaum. Wenn die Herzen während der 20 min dauernden Hypoxie in Normothermie mit einer procainhaltigen sauerstoff- und glucosefreien Blutersatzlösung durchspült wurden, waren die Myofibrillen relaxiert, die Schwellung der Mitochondrien dagegen wurde nicht reduziert. 30 min nach Erstickung wurde die Kontraktur stärker (Sarcomerlänge 1,7 μm). Nach 60 min bildeten sich Superkontraktionsknoten, einzelne Myofibrillen waren in Höhe der I-Bänder unterbrochen. Die Cristae der Mitochondrien wichen auseinander, die Schnittfläche der Mitochondrien hatte um 27% zugenommen. Während in Normotherapie eine Asphyxie des Tieres bereits nach 10 min die Herzmuskelzellen funktionell schwer schädigt, ist die Schädigung morphologisch erst nach 20 min eindeutig. Das bedeutet, daß für die elektronenmikroskopische Präparation eine Hypoxie von unter 10 min bedeutungslos ist. Hinsichtlich der morphologischen Manifestationszeit für die Unterbrechung der Sauerstoffversorgung stimmen unsere Befunde an Herzmuskelzellen gut mit vergleichbaren Angaben an Leberzellen überein.
    Notes: Summary In heart muscle cells of the left ventricle of rats the distribution of cell organelles and their reaction to hypoxia were investigated by electron microscopy. In normal hearts fixed by perfusion with aldehydes, the mean sarcomere length was 2.2 μm. 27% of the longitudinal sectional area was occupied by mitochondria, 55% by myofibrils and 18% by sarcoplasmic reticulum and ground plasm. The mitochondria situated in rows between the fibrils were oval and measured 2.3 times more in length than in width. There was no difference between cells from subendocardial and subepicardial regions. 10 min hypoxia (complete occlusion of the trachea) did not affect the appearance of muscle cells but diminished the number of glycogen granules. After 20 minutes the area occupied by mitochondria was increased by 16%, the mitochondria between the myofibrils were more spherical and only 1.5 times longer than wide. The sarcomeres shortened to 2.0 μm. With hypothermia (25–30°C) hypoxia of 20 minutes duration did not affect the cell structure. Perfusion of the heart by a saline solution, which contained procaine but neither oxygen nor glucose, for 20 minutes prevented shortening of the sarcomeres but not swelling of the mitochondria. 30 minutes after occlusion of the trachea the myofibrils shortened to a sarcomere length of 1.7 μm. After 60 minutes irregularly and excessively contracted myofibrils appeared and some sarcomeres were interrupted at the level of the I-bands. In some of the swollen mitochondria the cristae were widely separated. The increase of the area occupied by mitochondria was 27%. Asphyxia affects heart muscle cells severely with respect to function within 10 min, but morphologically it takes 20 min before a definite effect can be noticed. As to the time after which lack of oxygen is manifested morphologically, our results are consistent with findings in liver cells.
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  • 94
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    Cell & tissue research 110 (1970), S. 540-558 
    ISSN: 1432-0878
    Keywords: Cerebral cortex ; Synapses ; Rat ; Postnatal differentiation ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of layers I and II of the motor cerebral cortex of rat brain has been studied at birth, 4, 7 and 14 days postnatal and in the adult. Compared with the adult, neonatal rat motor cortex exhibited a large extracellular space which decreases with increasing age. At all stages studied the neurons were seen to contain the organelles usually found in adult neurons. Growth cones were present in decreasing numbers up to 14 days old. Synapses were detectable at birth and there was an obvious increase in their number throughout the postnatal development. At the earliest stages studied there was a lack of specialization characteristic of the adult. Many synapses were either avesicular or relatively so and lacked the high degree of modification of adult pre- and postsynaptic membranes. By 7 days after birth many synapses existed which in all morphological respects resembled those of the adult, and by 14 days, the majority were of the adult type. These findings, particularly with reference to the postnatal development of synapses, have been discussed in relation to the known electrophysiological findings.
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  • 95
    ISSN: 1432-0878
    Keywords: C cells ; Thyroid ; Rat ; Ultimobranchial origin ; Differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Nos observations confirment l'origine ultimobranchiale des cellules C de la thyroïde du rat. L'évolution des corps ultimobranchiaux (C.U.B.) a été étudiée à partir du 16ème jour de gestation, stade où ils fusionnent avec l'ébauche thyroïdienne. Dès le 17ème jour, les premières cellules C se différencient dans le C.U.B. inclus dans la thyroïde. Au 18ème jour, elles sont plus nombreuses et commencent à se disperser dans les cordons thyroïdiens. La migration des cellules C est particulièrement importante au 19ème jour. A partir du 20ème jour, les signes d'activité sécrétoire s'intensifient très nettement. A la fin de la vie foetale, les cellules C sont comparables aux cellules C adultes. La differenciation des cellules parathyroïdiennes précède nettement celle des cellules C.
    Notes: Summary Our observations confirm the ultimobranchial origin of the C cells of the rat thyroid. We studied the development of the ultimobranchial body from the 16th day of pregnancy, when there is fusion with the thyroidian anlage, onwards. As early as the 17th day, the first C cells differentiate in the ultimobranchial body which is included into the thyroid. On the 18th day, they are more numerous and start to scatter throughout the thyroidian cords. The migration of the C cells is especially obvious on the 19th day. From the 20th day onwards, there is marked increase in secretory activity. At the end of the foetal life, the C cells resemble those of the adult. The differentiation of the parathyroid cells significantly precedes that of the C cells.
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  • 96
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    Cell & tissue research 107 (1970), S. 447-453 
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Trypsin-dissociation ; ACTH stimulation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron micrographs of trypsin-dissociated rat adrenal showed predominantly intact rounded cells without internal damage. The population contained cells from the glomerular, intermediary and fascicular zones with cells from the zona fasciculata predominant. The presence or absence of cells from the reticular zone could not be determined. Cells from the medullary zone were absent. The addition of adrenocorticotropic hormone (ACTH) to the cellular suspension for 2 hours produced corticosterone. However, these stimulated cells did not display any significant ultrastructural change.
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  • 97
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    Cell & tissue research 108 (1970), S. 487-500 
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Residual lumen ; Epithelial cells ; Fine structure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Histology, enzyme histochemistry, and electron microscopy of the epithelium covering the rat pituitary residual lumen was studied. The anterior and posterior epithelium have similar histological and histochemical appearance, although the posterior epithelium shows stronger enzyme reactions for an esterase and many dehydrogenases. Electron microscopic studies reveal that both epithelia form a continuous lining. Anterior epithelium is in immediate contact with the interstitial spaces of the anterior lobe, while the posterior epithelium is separated from the intermediate lobe by a continuous basement lamina. The cytological features of both epithelia are also remarkably similar with scanty rough-surfaced endoplasmic reticulum, inconspicuous Golgi apparatus, round or oval mitochondria, and moderate number of lysosomal bodies. The apical surface of these cells is covered by microvilli and in some, especially posterior epithelial cells, by numerous cilia. Anterior epithelial cells and the apical portions of the posterior epithelial cells contain a number of large vacuoles with material possibly related to the colloid within the residual lumen. Electron microscopic findings suggest that both epithelia are possibly active in transfer and/or disposal of the colloid material rather than being secretory themselves. Enzyme histochemical findings support the hypothesis of an active role of these cells in metabolic processes related to phagocytosis. Based on these observations the colloid seems to be the product of the anterior lobe function.
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  • 98
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    Cell & tissue research 110 (1970), S. 559-568 
    ISSN: 1432-0878
    Keywords: Cerebral cortex ; Rat ; Synapses ; Postnatal ; Quantitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Quantitation of synapses at different postnatal ages has been undertaken in the cerebral cortex of the rat. In this study axial ratios of presynaptic bags, proportion of cortex occupied by presynaptic bags and numbers of synapses per unit volume of cortex have been estimated. Observations on synaptic vesicle packing densities have also been made. Synaptic bags become increasingly spherical up to 7 days of age and become more elongated thereafter. The proportion of cortex occupied by presynaptic bags increases rapidly up to 7 days of age and then at a decelerated rate up to maturity. The number of synapses per unit volume increases slowly over the first four days after which there is a rapid increase to 14 days, followed by a decelerated rate. The average presynaptic bag shows marked changes in volume with increasing age which indicate the probability of two stages of synaptic development. This two stage development is further reflected in the estimates on vesicle packing densities. The implications of the results are discussed in relationship to changes in functional activity of the cortex during postnatal development.
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  • 99
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    Cell & tissue research 110 (1970), S. 569-587 
    ISSN: 1432-0878
    Keywords: Subtotal Pancreatectomy ; Rat ; Islet Regeneration ; Excretory Duct System
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Männliche Ratten wurden bei einem Gewicht von 80–100 g subtotal pankreatektomiert (5% Rest) und zu verschiedenen Zeitpunkten nach der Operation abgetötet. Bei diesen wie bei unbehandelten Kontrolltieren wurde die Neubildung von Inselgewebe aus dem exkretorischen Gangsystem elektronenmikroskopisch untersucht. — Es konnte gezeigt werden, daß die Inselneubildung von Gangzellen ausgeht, welche ein auffallend helles Zytoplasma besitzen und samt ihren Kernen größer und abgerundeter sind als ihre Nachbarzellen. Diese Zellen wandern vom Lumen ab, wobei die entstehende Lücke zum Lumen zu jeweils durch eine seitliche Ausdehnung des Zytoplasmas benachbarter Gangzellen geschlossen wird. Die abgewanderten hellen Zellen, die mit den lichtmikroskopisch beschriebenen „trüben Zellen“ identisch sein dürften, haben die Fähigkeit, sich zu Alpha-oder Beta-Zellen zu differenzieren. Dabei werden sie größer und das Zytoplasma dunkler. Sie behalten aber gleichzeitig einige Besonderheiten, die auf ihre Herkunft hinweisen. Die Regeneration des Inselgewebes, die vorwiegend von den zentroacinären Zellen ausgeht, setzt bald nach der Operation stark ein, schwächt sich dann aber kontinuierlich ab. In den immer ineffektiver werdenden Regenerationsvorgang werden zunehmend größere Gangabschnitte einbezogen. Die weitgehende Erschöpfung der Regenerationsfähigkeit fällt mit dem Auftreten eines manifesten Diabetes zwischen dem 40. und 60. Tag p.op. zusammen.
    Notes: Summary Male rats were subtotally pancreatectomized at a weight of 80–100 g according to the method of Foglia (5% of the total pancreas remaining). The animals were killed at different intervals after. In these rats, as well as in healthy controls, the new formation of islets out of the excretory duct system was studied by electron microscopy. Obviously the new formation of islets takes origin from certain cells of the ductular system which show a light cytoplasm and are larger and rounder than their neighbouring cells. The latter goes for their nuclei, too, even to a larger degree. These light cells migrate away from the ductular lumen and the gaps resulting from this are closed by long and thin processes of the cytoplasm of their neighbouring duct cells coming in contact with each other. The cells having migrated away seem to have an ability to differentiate into alphaor beta-cells. Most probably they are identical with the “trübe Zellen” described by light-microscopists. The higher the degree of differentiation in these cells is, the darker becomes their cytoplasm. But they still keep for some time morphological aspects indicating their origin from ductular cells. An intense regeneration of islet tissue starts soon after the operation from the centroacinar cells but it decreases continuously after. As the process of islet regeneration becomes more and more ineffective, an increasing number of larger excretory ducts are involved in it. The exhaustion of the ability for regeneration is correlated exactly in time with the onset of a manifest diabetes between the 40 th and 60 th day after operation.
    Type of Medium: Electronic Resource
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  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 111 (1970), S. 364-378 
    ISSN: 1432-0878
    Keywords: Rat ; Oocyte maturation ; in vitro studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary After cultivation in a modified Trowell-system (organ ciilture) oocytes of 12- to 40-day-old rats were studied under the light and electron microscope. The cultivation period was 72 hrs. Egg cells from primary and early secondary follicles which are characterized by the lack of a zona pellucida and by one or at most two very large Golgi's complexes located near the nucleus do not show any alterations. The other egg cells are characterized by membrane packages which can otherwise only be observed in mature egg cells right before or after the ovulation. Meiotic processes or the formation of polar bodies are only seldom to be seen. These egg cells are surrounded by a thick zona pellucida. From these findings the following conclusions can be drawn: 1. In organ cultures meiotic processes are prevented by the inhibitory influence of follicle cells (Foote and Thibault, 1969). 2. A cytoplasmic maturation proceeds independently. 3. In-vivo an inhibitory factor influences the cytoplasmic maturation. This inhibition is not observed in the organ culture. Thus we can be sure that it develops outside the ovary. 4. The synthesis of the zona pellucida continues in-vitro.
    Type of Medium: Electronic Resource
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