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  • 1970-1974
  • 1965-1969  (14)
  • 1969  (11)
  • 1967  (3)
  • Electron microscopy
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 129 (1969), S. 109-127 
    ISSN: 1432-0568
    Keywords: Embryology ; Enzyme histochemistry ; Electron microscopy ; Small intestine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The histochemical activity of alkaline (AlPh) and acid phosphatases (AcPh), adenosine triphosphatase (ATPase), monoamine oxidase (MAO), succinic (SDH), isocitric (ICDH), glucose-6-phosphate (G6PDH) and lactic (LDH) dehydrogenase and leucinamino-peptidase (LAP) was studied in the duodenal wall of the chicken during pre- and postnatal growth. The morphogenesis of the developing epithelium was studied by electron microscopy. In 8-day-old embryos weak activity of all the enzymes but AlPh was observed in the cytoplasm of the epithelial cells of the mucosa. During the last third of the prenatal growing period the activity of AlPh, ATPase, MAO, SDH, ICDH, G6PDH and LAP increased strongly in the epithelium. In the adult chickens the epithelium exhibited strong activity of all the enzymes studied but LAP, the activity of which was moderate. The most intense activity of AlPh, AcPh, MAO and LAP was located in the cytoplasmic region adjacent to the bowel lumen, i. e. the microvillous and terminal web area of the epithelial cells. By electron microscopy, and inactive phase in the development of the epithelial microvilli was seen from the 10th to the 16th incubation day, followed by slow (16th–19th) and rapid (at about the time of birth) growing phases. The differentiation and the growth of the microvilli occurred at about the same time as the appearance of the enzymes in the apical cytoplasmic region of the epithelial cells. During the last third of the prenatal life the volume of the epithelial cells increased greatly, as did the number of mitochondria, lysosomes, vesicles and saccules of the Golgi apparatus. The crypt cells and the villus epithelial cells did not show similar morphological and enzymatic characteristics. The fine structure of the crypt cells resembled that of the non-differentiated embryonic epithelial cells of the duodenal mucosa.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1106
    Keywords: Electron microscopy ; Pontine nuclei ; Experimental neuroanatomy ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The electron microscopical changes occurring in the pontine nuclei following unilateral lesions of the primary sensorimotor cortex have been studied in 7 cats with a survival time from 2–23 days. A description is also given of the fine structure of the pontine regions in receipt of the fibres. These regions are shown in Fig. 1. The study shows that the boutons are practically only in synaptic contact with dendrites. The bouton density on these is only 16%. The boutons are of the en passage and terminal type, with the latter as the most common (Figs. 4a-e). The synaptic vesicles are rounded or elongated. The formaldehyde fixed material had 17.8% boutons with vesicles of the elongated type; the material fixed with a mixture of formaldehyde and glutaraldehyde had only 11.5% of such boutons. The degenerating boutons show the dark type of reaction and the majority of the corticopontine fibres are of the type shown in Figs. 4d and 4e. Astrocytes and microglial cells participate in the removal of degenerating boutons and terminal fibres. Degenerating boutons are present even at the 23 day stage and some have apparently only started to degenerate.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 101 (1969), S. 72-87 
    ISSN: 1432-0878
    Keywords: Cell differentiation ; Keratin ; Electron microscopy ; Reptiles ; Skin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epidermis of Anolis carolinensis is renewed periodically by molting. Prior to the molt the distinct layers of the epidermis, namely, the Oberhäutchen, β, mesos, and α layers, are formed in sequence from a morphologically homogenous population of basal cells. The Oberhäutchen, the first cell layer to form, has spinules on the surface which interdigitate with the overlying cells of the clear layer. The cells of the Oberhäutchen develop 80 Å filaments similar to those in the cells of the α layer. Beneath the Oberhäutchen is the β layer, the cells of which develop membrane-bounded packets containing a homogenous material during the early stages of differentiation. Later 100–500 Å thick fibrils are formed in the membranebounded packets. The fully keratinized cells, however, are packed with filaments 30 Å in diameter separated by an electron dense amorphous matrix, very similar to β-type keratin found in the feather rachis. The cells of the α layer, which is immediately below the β layer, contain 80 Å filaments very similar to the α-type keratin found in hair cortex and keratinizing stratified epithelia of mammals. Large quantities of glycogen are found in the cells of each layer during their genesis. Even though a stratum granulosum is not found underneath the α layer, the cells of the clear layer develop bodies which have histochemical and ultrastructural characteristics of keratohyalin granules. The old epidermis is then shed in toto at the junction of the clear layer (above) and the Oberhäutchen (below).
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 101 (1969), S. 28-62 
    ISSN: 1432-0878
    Keywords: Electron microscopy ; Islet of Langerhans ; Pancreatic hormones ; Classification of endocrine cells ; Stereology of endocrine granules ; Biostatistics ; Insulin immunization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pancreatic islet in the mouse has a highly complex and heterogeneous structure. It contains Aa, Ab, Ac, B, C, D, E, and F cells. The classification of cell types is primarily based on the shape, size and electron opacity of secretory granules and on the spatial relationship of the granules to their unit membranes. Morphological evidence is supported by a statistical analysis of the size distribution of granules and of their membranes. Experimental immunization of mice with insulin, provides additional data to support the existence of eight different cell types in the islet of the normal animal and reveales marked immunological stimulation of B cells, secondary stimulation of Aa, D and F cells, atrophy of Ac cells and hyperplasia of C cells. It is proposed that corresponding cell types exist in other mammals and man. The experimental insulin immunization process appears to perform an immunofunctional analysis of the islet, and suggests that in mice the Aa, D and F cells might be involved in cell energy supply. Lipocaic and some pancreatic factors with insulin-like activity (NSILA) will likely find their morphological equivalents. It is proposed that chemical solubility techniques represent the most promising avenues of approach to the isolation of secretory products from the endocrine pancreas, and that the assay of these extracts should primarily be conducted at the cell level.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 102 (1969), S. 193-204 
    ISSN: 1432-0878
    Keywords: Electron microscopy ; Enterochromaffin cell ; Duodenum ; Histological stainings ; Intestinal mucosa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Methods for light and electron microscopic comparison of individual argentaffin and argyrophil enterochromaffin cells (EC) in the sheep duodenal mucosa are described. These silver procedures were applied for light microscopy to Epon-embedded sections. The adjacent sections were examined with the electron microscope. The most specific characteristics of the argentaffin and argyrophil EC in electron microscopy are highly osmiophilic cytoplasmic granules. In one cell type these granules are smaller and more roundish than in the another type. These two cell types are stainable both by the argentaffin and argyrophil reactions. No essential difference can be observed in the localization of these elements. It is suggested that both cell types belong to the enterochromaffin system. Both silver methods are also suitable for the light microscopic identification of other intestinal structures in sections adjacent to that sectioned for electron microscopy.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 102 (1969), S. 172-181 
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Dehydration ; Electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Der Nucleus supraopticus der Ratte, die einer Dehydratation ausgesetzt war, wurde ultrastrukturell-morphometrisch analysiert. Dabei zeigte sich, daß die relativen Volumenanteile der einzelnen Zellkompartimente während der fünftägigen Durstperiode eine auffallende Konstanz aufweisen. Hingegen läßt sich eine absolute Zunahme der Einzelzellvolumina und somit auch der an der Synthese und Sekretion der Neurohormone beteiligten Zellkompartimente feststellen. Die vorliegenden Befunde sprechen für einen beschleunigten Abtransport des neurosekretorischen Materials bei gesteigerter Synthese. Auf eine optimale Standardisierung der Perfusionsmethode bei Untersuchungen am neurosekretorischen Zwischenhirnsystem wird hingewiesen.
    Notes: Summary The supraoptic nucleus of the dehydrated rat has been analysed by electron microscopy and morphometry. With that it appears, that the relative volumes of the different cell compartments are striking constant. Otherwise one can see an absolute increase of the cell volume together with the cell compartments which take part at the synthesis and secretion of the neurohormones. These results are expression of an accelerated move of the neurosecretory material during increased synthesis. The importance of an optimal standardization of the perfusion-method in investigations of the neurosecretory system is demonstrated.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 102 (1969), S. 153-171 
    ISSN: 1432-0878
    Keywords: Toad ; Median eminence ; Ependyma ; Neurosecretion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The primary plexus of the toad hypothalamic-adenohypophysial portal system has two types of loops. The short loops are localized in the external region of the median eminence and surrounded by nerve endings and glial cells. The long loops approach the ependymal lining of the median eminence. The ascending and descending branches of these loops are surrounded by nerve and ependymal endings and glial cells. The actual subependymal portion of the long loops is virtually in contact with ependymal processes only, which form a “cuff” interposed between this portion of the long loops and the fibres of the hypothalamic-neurohypophysial tract. Many of the vascular endings of the ependymal processes have electron dense granules whose diameter ranges between 700 and 1400 Å. The ultrastructure of the ependymal cells suggests that these granules are transport material and not secretory material. This anatomical arrangement linking the ependyma of the median eminence and the long loops of the primary plexus of the hypothalamic-adenohypophysial portal system makes the possibility of an interrelationship between the cerebrospinal fluid and the portal blood very considerable.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 102 (1969), S. 182-192 
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Dehydration ; Electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Der Hypophysenhinterlappen von Ratten, die einer Dehydratation unterworfen waren, wurde ultrastrukturell-morphometrisch untersucht. Als wichtigster Befund wurde bereits nach 36stündiger Dehydratation eine massive Abnahme der Neurosekretgranula festgestellt. Gleichzeitig ist ein signifikanter Anstieg der Fettkörper in den Pituicyten zu verzeichnen. Die Fettkörper können nach Ansicht der Autoren als Endprodukt der Membranreste oder der Trägersubstanz des Neurohormons interpretiert werden. Eine Mitbeteiligung der Lysosomen bei ihrer Verarbeitung wird diskutiert.
    Notes: Summary The neurohypophysis of the rat after dehydration has been studied by electron microscopic and morphometric methods. As the main result we found a massive decrease of the neurosecretory granules already at a dehydration of 36 hours. At the same time one can note a significant increase of fat vacuoles in the pituicytes. These fat vacuoles could be the final product of residual membranes or of the carrier substance of the neurohormones. The possibility of a functional role of lysosomes in the catabolism is discussed.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 102 (1969), S. 483-506 
    ISSN: 1432-0878
    Keywords: Organon vasculosum ; Laminae terminalis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das OVLT stellt jenen Abschnitt der Lamina terminalis dar, der durch eine eigentümliche, reiche Vaskularisation auffällt. Die von der Basalmembran bedeckte äußere Hirnoberfläche dringt an einer oder mehreren Stellen tief und spaltenartig in das OVLT ein. Dieser Spalt, der Bindegewebselemente und Gefäße enthält, verzweigt sich immer mehr und bildet ein aus 0,1–0,2 μ breiten Spalten bestehendes, labyrinthartiges System. Zum großen Teil füllen Gefäße vom Kapillartyp die größeren bindegewebigen Räume aus. Das Endothel der Kapillaren ist allgemein dünn und z. T. fenestriert. Die Bindegewebsräume und mit ihnen die Gefäße können sich dem Ventrikel derart nähern, daß sie von ihm durch nur eine einzige kubische Ependymzelle getrennt werden. Der Stützapparat des Organs wird in erster Linie von den Ependymzellen gebildet. Ihre langen basalen Fortsätze durchschneiden die Gehirnwand im Gebiet des OVLT und nehmen mit ihren Endigungen am Aufbau der Wand der Bindegewebsspalten und der äußeren Hirnoberfläche teil. In einem Teil der Ependymfüße findet man zahlreiche längliche, lysosomenartige Körper. Häufig kommen in die Tiefe der Substanz des OVLT eingedrungene Ependymzellen vor, welche nicht selten Zilien enthalten. Unter den Gliazellen konnten in erster Linie Astrozyten identifiziert werden. Die lichtmikroskopisch im OVLT beschriebenen sog. Parenchymzellen erweisen sich im Elektronenmikroskop als kleine, primitive Neurone. Ein großer Teil der Nervenfasern des Neuropils enthält granulierte Vesikel (Durchmesser zwischen 650 und 950 Å), die im allgemeinen eine runde oder ovoide Gestalt besitzen, obwohl auch tubulös ausgezogene Formen vorkommen. Die Nervenfasern welche die granulierten Vesikel enthalten, verlaufen nahe zur Kammeroberfläche, allgemein in der Längsachse des OVLT, wobei sie die länglichen Ependymzellen überkreuzen; in der Nähe der Endigung der basalen Ependymfortsätze wenden sie sich parallel zu letzteren und endigen zusammen mit ihnen frei am Rand der Bindegewebsspalten. Je ein solches, aus basalen Ependymfasern und Axonen bestehendes Bündel wird mehr oder weniger vom bindegewebigen Spalt umfaßt. Die Axonendigungen enthalten außer den granulierten Vesikeln und Mitochondrien auch zahlreiche synaptische Vesikel. Einige freie Axonendigungen wurden auch auf der freien Oberfläche des OVLT gefunden. Die Frage nach der Funktion des Organs wird an Hand der elektronenmikroskopischen Befunde diskutiert. Es wird für möglich gehalten, daß humorale Faktoren — ähnlich wie in der Eminentia mediana — aus den Axonendigungen in die Blutbahn gelangen; darauf scheinen die freien Endigungen am Rande des bindegewebigen Spaltensystems, die granulierte und synaptische Vesikel enthalten und die teilweise fenestrierten Kapillaren hinzuweisen, welche den aufgezweigten Bindegewebsraum „drainieren“.
    Notes: Summary OVLT is that part of the terminal plate which is characterized by its rich vascular supply. The brain surface covered by a basement membrane forms deep, cleft-like invaginations containing vessels and connective tissue elements. These connective tissue spaces dividing into 0.1 to 0.2 μ end branches are parts of a labyrinthic system in the interior of the organ. The vessels, mostly of the capillary type, are situated in the main clefts; their endothelium often shows fenestration. Some of the capillaries may approach the ventricle to such an extent that they are separated from it by a single ependymal cell. The supporting apparatus of the OVLT is mainly represented by elongated ependymal cells. Their long basal processes traverse the terminal plate to take part with their foot-like endings in the formation of the brain surface and that of the connective tissue spaces. Groups of special ependymal cells often exhibiting cilia may occur in the interior of the organ. Glial cells are mainly represented by astrocytes. The so-called parenchymal cells described in the light microscopy can be identified as small, primitive neurons. A great part of the nerve fibres in the OVLT contains granulated vesicles the diameter of which varies between 650 and 950 Å. The nerve fibres are mainly running vertically between the ependymal processes while at their terminal portion they assume a parallel course to the ependymal processes and end with them at the margin of the connective tissue spaces. Besides granulated vesicles, these free axon terminals contain numerous synaptic-like vesicles and several mitochondria. Some of the free terminals may occur also on the outer surface of the OVLT. The possible functions of the organ are discussed on the basis of the present findings. The hypothesis is raised that — similarly to the median eminence — humoral controlling factors may be released into the vessels. This hypothesis seems to be supported by the presence of free axon terminals containing granulated and synaptic vesicles and the existence of numerous, partly “fenestrated” capillaries draining the connective tissue spaces.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 101 (1969), S. 394-400 
    ISSN: 1432-0878
    Keywords: Oocyte ; Electron microscopy ; Meiosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The time and frequency of occurrence of granular cytoplasmic bodies in oocytes of the golden hamster has been investigated. The bodies are first seen immediately after birth when most of the germ cells have commenced meiotic prophase. They increase in frequency until approximately twelve days post-natal, at which time most oocytes have attained the dictyate stage. After this, frequency of occurrence of the bodies declines. Very few have been noted in adult material. The possible significance of the bodies is discussed.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Clinical and experimental medicine 149 (1969), S. 283-293 
    ISSN: 1591-9528
    Keywords: Phytohemagglutinin ; Immunoblast ; Lymphoblast ; Lymphocyte ; Electron microscopy ; Phytohämagglutinin ; Immunoblast ; Lymphoblast ; Lymphocyt ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Kulturen von Blutlymphocyten mit und ohne Zusatz von Phytohämagglutinin (PHA) wurden im Licht-bzw. Elektronenmikroskop untersucht. Es fanden sich: a) kleine und mittelgroße Lymphocyten, b) große RNS-reiche, durch PHA stimulierte Zellen und c) Makrophagen. Die PHA-Zellen lassen sich lichtmikroskopisch als „blastenartig“ bezeichnen. Im Elektronenmikroskop ist ihre Morphologie nicht einheitlich. Wir fanden lymphoblasten- und immunoblastenähnliche PHA-Zellen. Zu den Makrophagen könnten fließende Übergänge bestehen. Offenbar nur ein Teil der in vitro entstehenden PHA-Zellen kann den in vivo, immunkompetenten“ Zellen gleichgesetzt werden.
    Notes: Summary Cultures of blood lymphocytes incubated with and without phytohemagglutinin (PHA) were examined under light- and electron microscope. The following types of cells were found: a) small and medium size lymphocytes, b) large, RNA-rich, stimulated cells and c) macrophages. The PHA-cells of healthy individuals are large, showing a nucleus with nucleolus and a cytoplasma rich in free granules, but poor in ergastoplasma. Occasionally vacuoles of various sizes and osmiophilic inclusions are seen. Under light microscope these cells are similar to blastlike cells. Electron-microscopically the morphology of the PHA-stimulated cells is variable. We observed a) lymphoblast-like cells, b) immunoblast-like cells and c) macrophages. Our observations revealed, that only a part of the in vitro stimulated PHA-cells resembles immunocompetent cells. According to morphologic criteria the production of immunglobluins in vitro seems to be limited.
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  • 12
    ISSN: 1432-1106
    Keywords: Deiters' nucleus ; Electron microscopy ; Primary fibres ; Operated cats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following transection of the vestibular nerve in cats, the electron microscopical changes occurring in the lateral vestibular nucleus were studied after survival periods of 2–11 days. Material for study was taken from the rostroventral part of the nucleus of Deiters since this is known to receive the primary vestibular fibres. Degeneration of terminal boutons is evident two days after the lesion. Degenerating boutons show an increased electron optic density, mitochondrial changes and a loss of synaptic vesicles. They are often surrounded by a pericellular space filled with flocculent (probably protein) material. At three days and later this space is occupied by processes of astrocytes or of a type of phagocytic cells which surround or engulf the degenerating boutons. Nine to eleven days after the lesion almost all degenerating boutons have disappeared. There is evidence of phagocytosis of axons and myelin sheaths by astrocytes but mainly by phagocytes of yet undetermined origin. The “filamentous type” of bouton degeneration has not been observed. Degenerating boutons are found on neuronal perikarya and on proximal as well as on thin distal dendrites and on spines. They are common on small and medium-sized cells, but have also been seen on some giant cells. The degenerating boutons do not form series of synaptic complexes. Degenerating fibres and boutons have so far been found only ipsilateral to the lesion. The findings confirm and extend those made in corresponding experiments with silver impregnation procedures, but emphasize the limitations of the latter methods as regards conclusions concerning synaptic contacts.
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  • 13
    ISSN: 1432-1106
    Keywords: Deiters' nucleus ; Electron microscopy ; Purkinje axons ; Operated cats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present paper is an experimental study on the mode of termination of cerebellar corticovestibular fibres in the cat. The distribution of degenerating terminal structures as this appears in electron micrographs of eight animals with a survival time from three up to eleven days is described. The early stage of degeneration of Purkinje cell axons is a filamentous reaction during which fibres as well as boutons are enlarged and filled with filaments. The initial reaction is followed by shrinkage, and many fibres and boutons are at the 4 day stage electron dense, and no filaments can be recognized. Other fibres and boutons show intermediate stages of degeneration. Only dark degenerating axons and boutons are present at the 11 day stage. The observations are related to those made in other nuclei and regions where degeneration has been described in electron micrographs. Degenerating terminal myelinated fibres ending with terminal and en passage boutons are found. An attempt is made to correlate the findings with those made in normal animals and in Golgi sections. The mode of termination and the pattern of branching of Purkinje cell axons are discussed. The degenerating terminal structures are in synaptic contact with cells of all sizes and with all parts of the neurons, i. e., soma, proximal and distal dendritic trunks and spine-like projections. Elongated and rounded synaptic vesicles are present in the degenerating boutons. The glial reaction adjacent to degenerating boutons is also described, and brief mentioning is made of findings in the intracerebellar nuclei of the same animals. The findings in these nuclei are essentially the same as those made in the lateral vestibular nucleus.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 3 (1967), S. 435-442 
    ISSN: 1432-0428
    Keywords: Plasma insulin ; Pancreatic insulin ; Rabbit ; Pregnancy ; A-cells ; B-cells ; Electron microscopy ; Glucagon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Le contenu en insuline du plasma de lapins normaux et en gestation a été étudié par rapport à la quantité d'insuline qui pouvait être extraite de leurs pancréas. — Le contenu plasmatique moyen en insuline des lapins normaux, utilisés comme témoins, était de 25μU/ml (entre 18 et 33) et l'insuline extraite de leurs pancréas était de 3.56μg/100 mg de tissu (entre 3.33 et 3.76). — Lorsque la gestation était à un stade avancé, le contenu en insuline dans le sang s'élevait à 56μU/ml (entre 37 et 81), alors que l'insuline extraite du pancréas tombait à 1.17μg/100 mg de tissu (entre 0.65 et 1.73). — L'ultrastructure des cellules A et B pendant la gestation a également été étudiée. La teneur des granules B en insuline diminue et les cellules A présentent des signes évidents d'une haute activité. — Les observations précédentes suggéreraient que lors de la gestation avancée, une synthèse et une sécrétion de glucagon accrues augmentent l'activité sécrétrice du pancréas en insuline.
    Abstract: Zusammenfassung Bei normalen und graviden Kaninchen wurden die Plasma-Insulinspiegel und das aus dem Pancreas extrahierbare Insulin gemessen. — Die mittleren Insulinspiegel der normalen Kontrolltiere lagen bei 25μE/ml (zwischen 18–33), das Pankreasinsulin bei 3.56μg/100 mg Gewebe (3.33–3.76). Die Seruminsulin-spiegel steigen während der späten Schwangerschafts-stadien auf 56μE/ml (37–81) an und das extrahierbare Pancreas-Insulin nimmt auf 1.17μG/100 mg Gewebe (0.65–1.73) ab. — Wir untersuchten die Feinstruktur der Alpha- und Beta-Zellen während der Schwangerschaft: Dabei nahm das in den Beta-Granula gespeicherte Insulin ab und die Alpha-Zellen zeigten eindeutige Zeichen gesteigerter Aktivität. Die oben skizzierten Befunde könnten daraufhin deuten, daß während der späten Schwanger-schaftsstadien eine gesteigerte Glucagon-Synthese und Sekretion die insulinsekretorische Aktivität der Bauchspeicheldrüse erhöht.
    Notes: Summary Plasma insulin levels and extractable insulin of the pancreas of normal and pregnant rabbits have been studied. — The mean plasma insulin of non-pregnant controls was 25μU/ml (range 18 to 33); extractable pancreas insulin was 3.56μg/100 mg tissue (3.33 to 3.76). — The insulin level in the blood increases during late pregnancy to 56μU/ml (range 37 to 81) and the extractable pancreatic insulin decreases to 1.17μg/100 mg tissue (0.65 to 1.73). — The fine structure of B and A-cells has been studied in pregnancy: insulin stored in B granules decreases and the A-cells show definite signs of increased activity. — The above findings might be interpreted as suggesting that in late pregnancy an increased synthesis and secretion of glucagon augment the insulin secretory activity of the pancreas.
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