The adenohypophysis of the flounder,Pleuronectes flesus,and the minnow,Phoxinus phoxinus

Summary The pituitary gland of the flounder, Pleuronectes flesus, showed several unusual cytological features. Between the RPD and the PPD was a zone of cells that stained purple with Alcian blue—PAS—orange G. Many of these cells were apparently degenerating. In the PPD the strands and coils of presumptive STH cells showed a tremendous variation in both size and staining properties. In the PI there were two cell types, the PAS-positive one bordering the neurohypophysis. Around the periphery of the PI was a zone of chromophobic cells, and throughout the PI were numerous intracellular and extracellular acidophil spheres.No well defined ACTH cells were found in the RPD of the minnow (Phoxinus phoxinus). The Alcian blue—PAS—orange G technique distinguishes between blue TSH cells and purple GTH cells in the RPD and PPD. GTH cells from animals collected in the winter were vacuolated. The PI contained two cell types whose staining reactions and ultrastructure were extremely variable. Intra- and extra-cellular acidophil spheres were present.I should like to thank Dr. T. Kerr of the Zoology Department, Leeds University, for his help and encouragement, and Mr. J. Dingley of the Department of Zoology, Aberystwyth, for collecting the flounders.     

L'ultrastructure de l'adénohypophyse du crapaud Bufo bufo L.

Résumé Cinq types de cellules granulées se différencient au cours de la métamorphose dans la pars distalis de l'hypophyse du têtard de Crapaud.A la prémétamorphose apparaissent les deux types de cellules protidiques, les cellules glycoprotidiques de type II et des cellules glycoprotidiques d'un type intermédiaire. Cette dernière catégorie cellulaire disparaît au climax.A la prométamorphose se différencient les cellules glycoprotidiques de type IV.Au climax s'observent les cellules glycoprotidiques de type III.Les cellules glycoprotidiques de type II sont vraisemblablement responsables de la sécrétion de l'hormone thyréotrope (TSH). Il n'est pas encore possible de préciser la fonction des autres types cellulaires.Des fibres nerveuses ont pu être observées dans la pars distalis entre les cellules granulées.

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The ultrastructure of the adenohypophysis in the toad, Bufo bufo L.III. Cell differentiation in the pars distalis during larval growth

Summary Five granulated cell types can be distinguished in the Toad's pars distalis during larval growth.During premetamorphosis the two types of protidic cells appear, the glycoprotein containing cells of type II and an intermediary cell type which disappears during the climax.During prometamorphosis the glycoprotein cells of type IV are apparent.During the climax the glycoprotein cells of type III can be observed.The glycoprotein containing cells of type II probably produce the thyroid-stimulating-hormone (TSH). The function of the other cell types can not be specified for the moment.Nervous fibers have been observed in the pars distalis between granulated cells.

Tous nos remerciements vont à Mme Sidler-Ansermet photographe, Mlle Schorderet secrétaire, et Mlle Schutz technicienne, de l'aide qu'elles ont apportée à la réalisation de ce mémoire.     

Responses of prolactin cells of two euryhaline marine fishes,Gillichthys mirabilis and Platichthys stellatus,to environmental salinity

Summary Changes in the prolactin cells of the euryhaline marine teleosts Gillichthys mirabilis and Platichthys stellatus were studied by light and electron microscopy after transfer from sea water to fresh water. In seawater fish the secretory granules were smaller and the cellular organelles poorly developed. Within 3 hours after transfer to fresh water, the prolactin cells of Gillichthys exhibited definite functional activation: exocytosis of granules and development of rough endoplasmic reticulum (RER), Golgi systems and mitochondria. Concurrently, plasma sodium fell from about 172 meq/l to about 133 meq/l.As adaptation to fresh water progressed, prolactin cells of Gillichthys showed greater prominence of cellular organelles but granule storage was not detected even 10 days after transfer. Platichthys adapted to fresh water for 10 days showed RER in an expanded state containing irregular electron-dense material which was not seen in Gillichthys. Plasma sodium levels were much lower than in the controls. These results were in contrast to those obtained from euryhaline freshwater fishes such as Poecilia and Oryzias. Although the prolactin cells of euryhaline marine fish exhibited intense secretory activity when transferred into fresh water, the secreted prolactin per se appeared to be insufficient to maintain plasma sodium at seawater levels.We thank Dr. R. Foster for providing the acclimated starry flounders caught by the staff of the Bodega Marine Laboratory. Thanks are also due Mr. J. Underhill for photographic assistance, Mrs. A. Mos for microtechnical assistance, and Mrs. E. Reid for preparation of the graphs. This study was aided by NIH grant CA-05388 and NSF grant GB-23033.     

The cells that secrete the beaks in octopods and squids (Mollusca,Cephalopoda)

A single layer of cell secrets the hard cephalopod beaks. The beccublasts are tall columnar cells that separate the beak from the surrounding buccal muscles, and must serve to attach these muscles to the beak. Within the cell layer there are three types of cells. The first, and most frequently found contain cell-long fibrils. These fibrils may have contractile and tensile properties. Complex trabeculae extend from the beccublasts into the matrix of the beak. The fibrils are attached to these trabeculae and at the other end of the cells they are anchored near to the beccublast-muscle cell interface, closely associated with the muscles that move the beak. The second group of cells contain masses of endoplasmic reticulum the cysternae of which are arranged along the long axis of the cell. These cells also contain dense granules and are probably the major source of beak hard tissue. It is probable that each cell secretes its own column of beak hard tissue. The third group of cells cells contains a mixture of fibrils and secretory tissue. In the beccublast layer there are changes in the proportion of the three types of cells depending upon the region sampled. In the region where growth is most active there are mostly secretory cells, whereas near the biting and wearing tip there are mainly anchoring type cells.     

Histological,immuno- and enzyme-histochemical investigations on the adenohypophysis of the urodeles,Mertensiella caucasica and Triturus cristatus and the caecilian,Chthonerpeton indistinctum

Summary The pituitary glands of two urodelan species (Mertensiella caucasica, Triturus cristatus) and one caecilian species (Chthonerpeton indistinetum) were examined with histological (Alcian blue, Brookes' trichrome stain), enzyme histochemical (acid phosphatase, -naphthylacetate-esterase, acetylcholinesterase) and immunofluorescence techniques (anti-carp GTH, anti-ovine prolactin, anti-synthetic -MSH). In the pituitary gland of Mertensiella and Triturus six chromophilic cell types could be distinguished. A strong fluorescence was observed in the MSH-, GTH- and TSH-cells.In the pituitary gland of Chthonerpeton only five chromophilic cell types could be distinguished: in the rostral part of the pituitary gland the B₃-cell; in the basal region of the central area the B₂-cell; dorsocaudally the B₁-cell. The acidophilic cells were found in the central and caudal part of the pars distalis. The basophils of the pars intermedia could be observed in the dorsocaudal part of the pituitary gland surrounding the neurohypophysis. All acidophilic cells showed a strong immunofluorescence with anti-ovine prolactin (LTH).     

Chicken pars distalis development

Summary Anlagen of the pars distalis (Rathke's pouch), adjacent ectoderm, endoderm, infundibulum and mesenchyme left in situ were put in 3% glutaraldehyde between 1–3 pm and fixed overnight. Epon sections of this material from six White Leghorn, Gallus gallus, embryos fixed at each stage, and of two control partes distales from laying hens of the same flock were examined.At stage 17 (12 hours after formation) Rathke's pouch cells were stratified, uninnervated, non-vascularized and stellate, with high nucleo-cytoplasmic ratios and few organelles. Except for lipid inclusions, pouch cells did not appear appreciably different by stage 27, either regionally within the pouch wall or from the adjacent epithelioid cells.Apparent major changes indicative of cytoplasmic maturation by stage 27 included: reduction in number of polysomes; appearance of single-membraned, dumb-bell shaped to rounded, dense granula which were usually in basal position but also in areas of the Golgi apparatus; greater prominence of rough endoplasmic reticulum with cisternae containing dense material, and of the Golgi apparatus, notably with variously dense and/or coated vesicles and material; reduction in lipid inclusions by stage 24. Non-terminating axons in the infundibulum were first seen at stage 27.We found no convincing evidence for any possible morphogenetic or other relationship between the pars distalis and surrounding tissues. Melanophore-stimulating hormone-activity, reported to appear on day 5 of incubation, stored thyroid-stimulating hormone or pars distalis hormone granula or activities could not be identified. Rathke's pouch and other epithelioid structures may have been secreting, taking up nutrients and/or differentiating, activities which could be important for yolk sac development, nutrition and/or cytodifferentiation, respectively.Some results were reported at the Seventh Conference of European Comparative Endocrinologists in Budapest Hungary, Aug., 1973 (Betz and Jarskär, 1974).Part of work done on T. W. Betz's sabbatical leave awarded by Department of Biology, Carleton University, Ottawa, Canada, K 1 S 5 B 6 while additionally sustained by a North Atlantic Treaty Organization (NATO) Post-doctoral Fellowship in Science administered by National Science Foundation, Washington D.C., USA, 20550. My referees, Professors D. S. Farner, A.V. Nalbandov, R. L. Watterson and K. G. Wingstrand deserve special thanks. Professor Anders Enemar was a gracious host in so many important ways making my stay enormously worthwhile. Additionally supported by Swedish Natural Science Research Council (grant B 2180-22) and National Research Council of Canada (grants A 2822, T 541). We are grateful for the competent help of Ulla Wennerberg, Professor Björn Afzelius of Wenner-Grens Institut, Stockholm provided expert encouragement by endorsing our techniques.     

The outgrowth of rat cerebellum in organized culture

Summary The outgrowth of newborn rat cerebellum cultivated in the Maximow assembly was studied from the time of explanation until the end of the 1st week in vitro. Dynamic characteristics of migrating cells were investigated with time lapse microcinematography and with phase and interference contrast.Three types of cells were identified: bipolar fusiform cells, fibroblasts and macrophages. The ultrastructure of these cells as seen with scanning and transmission electron microscopes is described. Bipolar cells display the same characteristics as those of migrating granule cells in vivo. Differentiation of these cells towards neuronal types becomes evident at the end of the first week in vitro.Axonal as well as dendritic growth cones were examined, and their ultrastructural characteristics described. Attention is focussed into the abundance of smooth endoplasmic reticulum, which in supposed active growth has the form of thin cisternae, and, at rest or in retraction takes the form of large vesicles. In the latter case, filopodia disappear, and the tips of their processes acquire a bulbous shape.The authors acknowledge the support and advice of Dr. J. E. Gruner, and the expert technical assistance of Mrs F. Salomon for preparation of material, Mr. D. Le Cren for photographic work.     

Über Arthropoden-Abwehrstoffe. LVIII Zur Feinstruktur der Pygidialdrüsen des Gelbrandkäfers (Dytiscus marginalis L., Dytiscidae,Coleoptera)

Zusammenfassung Die Pygidialdrüsen von Dytiscus sezernieren eine Emulsion, die p-Hydroxybenzaldehyd, p-Hydroxybenzoesäuremethylester, Benzoesäure und ein Glycoproteid enthält. Ihre Loben sind aus zwei verschiedenen Arten von Drüsenzellen aufgebaut, den Kanalzellen, die die Einzelkanäle und den Sammelkanal umgeben, und den Tracheoblasten. Die chitinigen Einzelkanäle enden mit einer traubigen oder blasigen Anschwellung, die aus einer massiven inneren und einer schwammigen äußeren Wandschicht besteht, in einer Höhle der sekretorischen Zellen. Die Zahl der Blasen - und Trauben-Zellen ist etwa gleich. Die zentrale Höhle ist von Mikrovilli umgeben, die durch Mikrofibrillen in hexagonaler Packung ausgesteift werden. Wie die Untersuchung nach Gefrierätzung zeigt, ist die konvexe Seite der Mikrovilli-Membran dichter mit Partikeln besetzt als die konkave Seite. Beide Zelltypen haben ein ausgedehntes tubuläres glattes endoplasmatisches Reticulum; freie Ribosomen und granuläre Zisternen sind selten. In den Traubenzellen ist der Golgi-Apparat besser als in den Blasenzellen entwickelt. Die zentrale Höhle der Traubenzellen enthält eine fein-flockige Substanz, die der Blasenzellen ein dichtes osmiophiles Material. Die Sekretionsmechanismen, die Beteiligung verschiedener Typen von Vesikeln und anderer Zellorganellen an der Sekretion und die Unterschiede zwischen den beiden Drüsenzelltypen werden diskutiert. Es wird angenommen, daß die Hauptkomponenten des Sekretes eccrin ausgeschieden werden.

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On defense substances of arthropods LVIII the fine structure of the pygidial glands of the water beetle, Dytiscus marginalis L.

Summary The pygidial glands of Dytiscus secrete an emulsion containing p-hydroxybenzaldehyde, p-hydroxybenzoate, benzoic acid, and a glycoproteid (Schildknecht, 1970). Their lobes are composed of two different types of secretory cells, channel cells (which surround a channel, draining the secretory cell, as well as the collecting channel), and of tracheoblasts. The chitinous draining channel ends in the form of either a racemous or a bulbous swelling consisting of a massive inner and a spongy outer wall layer in a cavity of the secretory cell. The number of racemous and bulbous cells is nearly the same. The central cavity is surrounded by microvilli which are stiffened by microfibrils in a hexagonal packing. After freeze etching the convex surface of the microvilli reveals more membrane particles than their concave surface. Both cell types have an extended smooth surfaced tubular endoplasmic reticulum; the amount of free ribosomes and of granular cisternae is low. In the racemous cells the Golgi apparatus is better developed than in the bulbous cells. In the racemous cells the central cavity contains a fine-fluffy substance, in the bulbous cells a dense osmiophilic material. The mode of secretion, the participation of various kinds of vesicles and other cell organelles in this process, and the differences between the two types of secretory cells are discussed. It is assumed that the main components of the secretion are released in the eccrine way.

Wir danken der Deutschen Forschungsgemeinschaft für Sachbeihilfen.     

Nongranulated cells in the mouse adenohypophysis

Summary Follicular cells in the mouse adenohypophysis were studied electron microscopically. These elements appear to be very similar to the marginal cells that delineate both sides of the hypophyseal cleft.The mouse differs from most other species in that the follicular cells in the pars distalis and the marginal cells look completely inactive in young, intact animals. This makes the mouse exceptionally favorable for correlating morphological changes in the cells of both types with changes in the physiological state of the animal. Different treatments applied in the present investigation all induced morphological reactions in the follicular and/or marginal cells; these reactions were generally similar. Thus, morphological changes in the follicular or marginal cells should be considered as general phenomena accompanying many changes in the physiological state of the animal, rather than as a specific result of the treatment applied.In three experiments, the follicular and marginal cells were involved in the digestion of waste material from other cells. It is suggested that the morphological changes in the other experiments should also be interpreted as signs of such an activity.In the pars tuberalis of the young, intact mouse the follicular cells may show characteristics that in the pars distalis are found only under experimental conditions. Therefore, the follicular cells in this part of the hypophysis are probably in an active state.     

Two types of mammosomatotropes in mouse adenohypophysis

Summary Two types of mammosomatotropes (MS), the small-granule and vesicle-granule MS, were detected in mouse adenohypophysis by electron microscopy and immunohistochemistry. Both cell-types were immunoreactive to prolactin (PRL) and growth hormone (GH) antisera. The small-granule MS contained small, round, solid secretory granules about 100 nm in diameter, and were smaller than the classical GH and PRL cell-types. The vesicle-granule MS contained secretory granules like cored vesicles, and were larger than classical GH and PRL cells. Small-granule MS were immunoreactive to both PRL and GH antisera in the same region of the cell cytoplasm; the vesicle-granule MS, however, were immunoreactive to only PRL antiserum in most cytoplasmic areas, and a positive response to both PRL and GH antisera was confined to only certain small areas.     

Structural and ultrastructural features of boar bulbourethral glands

The morphological features of boar bulbourethral glands were examined by light and transmission microscopy. Bulbourethral glands are compound tubuloalveolar glands surrounded by a capsule of dense connective tissue and arranged in multiple lobules formed by endpieces and excretory ducts. Endpieces and excretory ducts are both lined by a single epithelium of mucous cells with a basal nucleus. Epithelial cells accumulate secretory granules containing neutral and carboxylated acid mucosubstances and a small amount of sulphated acid mucosubstances. The ultrastructure of epithelial cells varies according to the secretory cycle. In initial stages, the cells show a columnar shape and secretory granules unevenly distributed in the cytoplasm. As the synthesis of mucosubstances progresses, the amount of the secretory granules increases and the cellular shape becomes pyramidal. Secretory granules can contain inclusions and present differences among them according to their different phases of formation. In pyramidal cells, secretory products are released into the lumen by a merocrine mechanism.     

Modifications des cellules gonadotropes de la préhypophyse chez la ratte injectée de testostérone au cours du cycle oestral

Summary 4-day cyclic adult female Wistar rats were injected subcutaneously with testosterone propionate on diestrus 1 at 16:00 and on diestrus 2 at 10:00 respectively. Non-injected females served as controls. Autopsy was performed on diestrus 2 at 23:00, and on proestrus at 14:00 and 17:00 respectively. The blue Alcian-PAS staining was used to evidence FSH () and LH () pituitary cells.In control animals and in diestrus 2 injected females only a small number of FSH cells could be detected on diestrus 2 at 23:00. This number increased markedly on proestrus at 14:00 and decreased on proestrus at 17:00. A similar evolution was observed in diestrus 1 testosterone injected females, but the number of FSH cells appeared higher at any stage of autopsy in these females than in diestrus 2 injected females and in control rats.In control females, numerous LH cells were observed on diestrus 2 at 23:00. The number of these cells was diminished on proestrus at 14:00 and still more at 17:00. On the contrary few LH cells were detected in testosterone injected females on the evening of diestrus 2. An increase of these cells occurred on proestrus at 14:00, followed at 17:00 by only a weak diminution as established by comparison with control animals.An inhibition of FSH release and a suppression of the proestrus surge of LH were therefore supposed to cause, on one hand, the slowing up of follicular growth observed in diestrus 1 injected females and, on the other hand, the blockage of ovulation noted in both diestrus 1 and diestrus 2 treated animals.

Travail effectué avec l'aide de la D.G.R.S.T. Contrat n^o 72.7.0030.