The dopaminergic innervation of the goldfish pituitary

Summary The dopaminergic innervation of the goldfish pituitary gland was studied by immunocytochemistry at the electron-microscope level using highly specific antibodies against dopamine coupled to bovine serum albumin with glutaraldehyde. A satisfactory preservation of the tissue was achieved after immersion in 5% glutaraldehyde in phosphate buffer containing sodium metabisulfite to prevent oxidation of the endogenous dopamine. The immunocyto-chemical procedure was performed on Vibratome sections using the preembedding method. Immunoreactivity was restricted to part of the neurosecretory type-B fibers (diameter of the secretory vesicles lower than 100 nm) in which it was found to occupy the whole cytoplasm. Labeled fibers were observed within the neurohypophysis in the different parts of the gland and in the adenohypophyseal tissue where immunoreactive profiles were detected in close apposition to the different cell types. These data are in agreement with previous results obtained by means of radioautography and further support a role for dopamine in the neuroendocrine regulation of pituitary functions in teleosts.     

Possible physiological role of epidermal growth factor in the development of the mouse mammary gland during pregnancy

Epidermal growth factor stimulated cell proliferation in a primary mammary epithelial cell culture derived from mice at different stages of pregnancy. Moreover, the peptide hormone inhibited casein production induced by the synergistic actions of insulin, cortisol and prolactin. The inhibitory effect of epidermal growth factor was influenced by the gestational stages of the mammary gland. These effects of epidermal growth factor were exerted at physiological concentrations. The dual actions of epidermal growth factor on mammary cells implicate its participation in regulation of the growth and differentiation of the mammary gland during pregnancy.     

A Highly Sensitive Enzyme Immunoassay for Mouse β Nerve Growth Factor

Abstract: A sensitive two-site enzyme immunoassay system for mouse β nerve growth factor (NGF) was developed, based on the sandwiching of the antigen between anti-mouse β NGF antibody IgG coated to a polystyrene tube and anti-mouse β NGF antibody Fab'-linked β- d -galactosidase (β- d -galactoside hydrolase, EC 3.2.1.23). This method has the following advantages: (a) the procedures are simple and rapid compared to bioassay or two-site radioimmunoassay; (b) antibody Fab'-β- d -galactosidase complex is more stable than ¹²⁵I-labeled antibody; (c) purified β NGF is detectable at a concentration as low as 10 pg/ml. Our enzyme immunoassay was used to examine the levels of NGF in some tissues of mice. The submaxillary gland contained a high concentration of NGF. However, other tissues, such as the heart, brain, and skeletal muscle, and serum did not contain detectable NGF. These results support recent findings by other investigators that NGF was not found in the organs/tissues other than the submaxillary gland of mice.     

Molting in a parasitic nematode, Phocanema decipiens—VII. The mode of action of the ecdysial hormone

The cycle of aminopeptidase activity demonstrated by histochemical methods in the activated excretory gland could not be detected in homogenates. In the electron microscope, the secretory granules in dormant glands were dense and irregular in shape and the mitochondria elongate, relatively dense, and with a crenellated outer membrane. The excretory gland was activated when the neuroendocrine system was stimulated by farnesyl methyl ether. In activated glands the secretory granules became larger, less dense and the membranes began to fuse with membranes of the ductules which ramify through the gland. The mitochondria became swollen. Aminopeptidase activity was displayed by a large uniformly less dense granules but not by the denser granules, and was seen in the endoplasmic reticulum, Golgi apparatus and in the lumen of the ducts. It is suggested that the ecdysial hormone from the neurosecretory cells sets in train a sequence of events which leads to entry of water into the gland and consequent activation of the enzyme in the granules, and to changes in the membranes of the granules which facilitate fusion with the membrane lining the ducts.     

The secretory nature of the excretory gland cells of Strephanurus dentatus. 3. Proteinase inhibitors

A proteinase inhibitor(s) was found in extracts of the excretory gland cells, intestines, esophagi, reproductive organs, and body walls from Stephanurus dentatus adults. The specific activity of the inhibitor(s) in the excretory gland cell extract was 45–175 times greater than in the other tissues. It is heat stable at pH 5.0 and inhibits the esterolytic activity of trypsin and chymotrypsin using p-toluenesulfonyl-l-arginine methyl ester hydrochloride (TAME) and benzoyl-l-tyrosine ethyl ester (BTEE) as the substrates, respectively, and also the proteolytic activity of both chymotrypsin and trypsin using casein as the substrate. S. dentatus adults maintained in NCTC 109 medium, secreted a trypsin inhibitor.     

The ultrastructure of the sinus gland of Carcinus maenas (Crustacea: Decapoda)

Summary The sinus gland of Carcinus maenas consists of the swollen axonal endings of the neurosecretory cells of the major ganglia and acts as a storage release centre for the membrane bound neurosecretory material. These neurosecretory granules fall into five different types based on size and electron density. Their contents are released by exocytosis of the primary granules or smaller units budded from the primary granules.I thank Professor E. Naylor for his constant advice and Professor E. W. Knight-Jones, Department of Zoology, University College, Swansea, for the provision of laboratory facilities. I am grateful to the Science Research Council for the financial support. Finally, I thank the Electron Microscope Unit, Southampton General Hospital, where the work was completed.     

Elektronenmikroskopische Zytomorphologie der männlichen Brustdrüse

Zusammenfassung Im Vergleich zu lichtmikroskopischen Untersuchungen an der Mamma virilis wird anhand von 2 operativ entfernten Brustdrüsen eines 57 und 63 Jahre alten Mannes die elektronenmikroskopisch erfaßbare Zytomorphologie beschrieben. Die Befunde werden den physiologischen Wachstumsimpulsen dieses Organs gegenübergestellt und Fragen der Zelldifferenzierung, der Desquamation und apokrinen Sekretion beantwortet. Elektronenmikroskopisch werden am Drüsenepithel Basalzellen, größere Zellen der oberflächlichen Zellreihen und Myoepithelzellen unterschieden. Diese Zellen entsprechen den Gangepithelien der weiblichen Brustdrüse und besitzen intracytoplasmatische Filamente. Diese stellen ein häufiges Differenzierungsprodukt des Zytoplasmas dar. Mechanismen einer Sekretion waren nicht nachweisbar. In die Drüsenlichtung werden pseudopodienartig vorgewölbte Zytoplasmateile abgeschnürt (Extrasionsvorgang). — Superfiziale Zellen werden desquamiert, wobei die Zytolyse in den marginalen Zytoplasmaschichten erfolgt. Kern und Teile des Zytoplasmas gelangen in die Drüsenlichtung. — Die Befunde zeigen die von Lebensalter und Proliferationsreiz abhängigen Vorgänge eines permanenten Zellersatzes in der männlichen Brustdrüse an.

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Ultrastructure of the mammary gland of the human male

Summary The ultrastructure of two mammary glands obtained operatively from a 57-year old and a 63-year old man was compared to the structure observed in the light microscope, and related to stimuli controlling growth of the gland, cellular differentiation and desquamation, and apocrine secretion. The glandular epithelium, which is analogous to that of the female mammary gland, is differentiated into basic cells, large superficial cells, and myoepithelial cells. The cells have intracytoplasmic filaments, that may be a sign of differentiation. Mechanisms for secretion were not observed, although pseudopodia-like parts of the cytoplasm are extruded into the glandular lumen. Superficial cells are desquamated, followed by cytolysis of their margins. These findings illustrate the replacement of cells due to age and altered stimuli.

Frl. St. Walter, lt. Assistentin des elektronenmikroskopischen Labors, danken wir für Präparationen und Photoarbeiten.     

Les tissus élaborateurs d'hormones stéroïdes chez les amphibiens urodèles

Résumé Les cellules du tissu glandulaire du testicule et de la glande interrénale de pleurodèle montrent les caractères généralement observés dans les cellules stéroïdogènes. Des différences existent entre les deux tissus. Le reticulum endoplasmique du tissu glandulaire est très développé et présent dans toutes les cellules qui sont d'aspect homogène. Au contraire, le tissu interrénal montre deux aspects cellulaires différents. Le premier se caractérise par un reticulum endoplasmique lisse relativement peu développé par rapport au tissu glandulaire, par des mitochondries petites et nombreuses, enfin par des liposomes denses et petits. Le deuxième aspect au contraire, se distingue par le petit nombre de mitochondries souvent géantes et à crêtes plus fréquemment organisées en faisceaux, par des liposomes nombreux de grandes dimensions et peu denses aux électrons.Le tissu glandulaire est très peu touché par l'hypophysectomie. Le reticulum persiste plusieurs mois comme d'ailleurs l'activité 5-3 -hydroxystéroïde deshydrogénase. Dans le tissu interrénal, la proportion des cellules d'aspects différents varie au profit des cellules à lipides abondants et à grandes mitochondries. L'activité 5-3 -hydroxystéroïde deshydrogénase est longtemps décelable.Le rôle du reticulum endoplasmique du tissu glandulaire est discuté en fonction des observations réalisées dans d'autres cellules stéroïdogènes à reticulum abondant. La signification des deux aspects cellulaires observés dans l'interrénale est discutée en relation avec les résultats expérimentaux obtenus en particulier chez le rat.Cette étude révèle que les critères d'activité d'une cellule stéroïdogène sont délicats à établir et doivent être différents d'un tissu à l'autre.

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Tissues secreting steroid hormones in urodele amphibians

Summary The fine structure of testis glandular tissue and interrenal gland cells of Pleurodeles shows the general features observed in other steroïdogenic cells. Certain differences exist between the two tissues. The agranular endoplasmic reticulum of the glandular tissue cells is well developed and present in all cells of similar appearance. On the contrary, the interrenal tissue cells show two different features. The first is characterised by a poorly developed smooth endoplasmic reticulum, compared with that of the glandular tissue, by small and numerous mitochondria, and finally by small electron dense lipid droplets. The second feature is the small number of mitochondria often giant and with fascicles of straight tubular cristae and numerous large lipid droplets of low electron density.The effect of hypophysectomy on the glandular tissue cells seem very slight. The endoplasmic reticulum and the 5-3 -hydroxysteroid dehydrogenase activity persists for several months. In the interrenal tissue, the proportions of the two different cellular features are modified. Cells rich in lipids and with large mitochondria are more abundant. It is possible to demonstrate a 5-3 -hydroxysteroid dehydrogenase activity for a long time after hypophysectomy. The functional significance of the agranular endoplasmic reticulum is discussed in relation to some other observations on different steroidogenic cells with a well developed agranular endoplasmic reticulum. The significance of the two cellular features observed in the interrenal gland is discussed in connection with experimental data obtained in the frog and the rat.This study shows that it is difficult to define criteria of cellular activity, which probably differ from one tissue to another.

Equipe de Recherche associée au C. N. R. S. Cytologie Ultrastructurale n 129.     

Differential Expression of mRNA and Protein Encoding Retinal and Pineal S-Antigen During the Light/Dark Cycle

S-Antigen is a soluble cell protein unique to the retina and pineal gland. In the former, it is a well-characterized molecule that participates in light-induced signal transduction in photoreceptor cells. In the latter, the functional role is presently not known. The expression of S-antigen and its mRNA was examined in the rat retina and pineal gland throughout the diurnal cycle and with light interruption of the dark cycle. A cDNA for rat S-antigen was isolated from a pineal gland library to examine the mRNAs. A 1.7-kb mRNA for S-antigen was observed in both the pineal gland and the retina. Retinal S-antigen mRNA was expressed throughout the diurnal cycle and increased with light interruption of the dark cycle. In contrast, pineal gland S-antigen mRNA levels were detectable only during the dark and were absent preceding and during light. The phenotypic expression of immunoreactive S-antigen, identified with two S-antigen monoclonal antibodies (MAbs), MAb A9C6 and MAb C10C10, was analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel (PAGE) and isoelectric focusing (IEF) electrophoresis. Immunoblot analysis of gels after SDS-PAGE revealed a single 46-kDa protein in retina. In contrast, two bands of approximately 43 and 46 kDa were identified in the pineal gland. Immunoblots of the retinal extracts separated by IEF electrophoresis revealed five S-antigen isomers, which vary quantitatively throughout the diurnal cycle and when light interrupted the dark cycle. Immunoblots of the pineal gland samples separated by IEF electrophoresis indicated that the pineal gland possesses four pineal gland-specific forms of S-antigen in addition to the five forms present in the retina. The differences observed in the mRNA and protein analyses suggest tissue-specific structural components for S-antigen in the retina and pineal gland that are not regulated in the same manner.     

白鲟消化道形态学与组织学的初步观察

白鲟消化道具有肉食性鱼类的典型特征,其口咽腔结构既适合捕食又适合吞食与滤食水生动物。咽后消化道可分为食道、胃后行支、胃前行支、小肠、瓣肠、直肠与肛门。幽门盲囊似一致密器官,小肠与瓣肠连接处有一特殊淋巴器官,肛门两侧有腹孔。白鲟口咽腔被覆层扁平上皮,上皮内有味蕾分布。咽后消化道组织分层为粘膜(无粘膜肌层)、粘膜下层(小肠及瓣肠前部无)、肌层与外膜。粘膜上皮为单层柱状上皮,由纤毛柱状细胞、一般柱状细胞和杯状细胞组成,其间还散在有颗粒细胞和游走细胞。食道后部与胃的一般柱状细胞为分泌粘液的细胞,肠内的一般柱状细胞为吸收细胞。胃后行支及部分前行支固有膜内有消化腺,其余各部的固有膜为致密层。小肠前中部粘膜形成蜂窝状粘膜窦,无肠腺。除食道前部肌层中有横纹肌外,其余部的肌层均为平滑肌。外膜内结缔组织有的致密有的疏松,外膜表面细胞柱状或立方形或扁平。