Immunocytological identification of two cell types in the intermediate lobe of the hypophysis of salmonids: presence of ACTH and alpha-MSH]

The lead-haematoxylin positive cells (PbH+) of the rostral pars distalis react with antibodies anti-1-24 ACTH and anti-17-39 ACTH; the pars intermedia (PI) is composed of two cell categories, but only one is revealed with cyto-immunological techniques and contains ACTH and alpha-MSH in several Salmonid species.     

Sekretomotorische Fasern und Endigungen in der Adenohypophyse

Summary We demonstrated, in the pituitary of the animals examined, fibres which emerge from the Tr. hypothalamo-hypophyseal system and enter partly into the Pars intermedia and partlyvia the Pars tubularis into the Pars distalis and take their course directly towards the glandular cells. In the Pars distalis the nerve fibres end around the glandular cells in a special pericellular net.     

Immunohistochemical individualization of adenohypophyseal thyrotropic cells in the monkey Macaca irus, using a human anti-beta-TSH antibody

Using the indirect immunofluorescence technique and an antiserum against the specific beta subunit of human TSH, selective immunocytochemical staining was localized in a cell population of the pars distalis of the monkey Macaca irus. These thyrotropic cells, which were positive to aldehyde fuchsin, Alcian blue, and PAS, were localized on the one hand in the ventro-medial zone of the pars distalis, especially alongside the large vessels of this region, and on the other in the zona tuberalis, i. e. at the bottom of the pars tuberalis. Some cells, sparsely distributed, were seen in the posterior part of the lateral lobes of the pars distalis, in the vicinity of the pars intermedia. No thyrotropic cells were encountered in pars tuberalis. Pars intermedia and posterior lobe contained no cells immunoreactive to beta-hTSH. In females, the thyrotropic cells were more numerous and larger than in males. Generally the thyrotropic cells were round or oval in shape, sometimes they were polygonal.     

Immunocytochemistry of pituitary corticotroph cells in terrestrial turtle (Testudo mauritanica)]

The immunocytochemical and histochemical characters of the corticotroph cells of the Turtle adenohypophysis have been studied. These cells are localised in the rostral part of the gland and are revealed by Is anti ACTH (1-24) and (17-39). They are also colored with lead hematoxyline and PAS-Orange G. The corticotroph nature of these cells is confirmed by the study of their modifications after treatment with amphenone and ACTH. The Is anti ACTH also reveal most of the cells of the pars intermedia; while the Is anti beta-MSH reveals only these cells and some scatter cells of the pars distalis.     

Immunohistochemical study of the pars intermediate of the mouse pituitary in different experimental conditions.

Alpha-MSH, beta-MSH and ACTH have been localized in the cells of hypophyseal intermediate lobe by fluorescence histoimmunological technics. Elaboration and excretion of these polypeptides are enhanced after dehydration or adrenalectomy. The most evident variations are seen with alpha-MSH and ACTH after dehydration, with beta-MSH after adrenalectomy.     

Cytoimmunological study of the corticotrophic and corticomelanotrophic cells in the adenohypophysis of Boops salpa L. (marine teleost) in different experimental conditions (variation of salinity and of background color)]

The cytoimmunological study of the adenohypophysis of Boops salpa (marine Teleost), in different experimental conditions confirmed that the MacConaill's hematoxyline-positive cells contain: 1. ACTH (Corticotrophic Hormone) in the pars distalis, 2. MSH (Melanocyte-Stimulating Hormone) and ACTH in the pars intermedia.     

Influence of alpha-MSH and ACTH on cortical bone remodelling in hypophysectomized rats.

Hypophysectomy increases both periosteal resorption and endosteal apposition along the femur diaphysis in rat. Administration of alpha-MSH decreased the periosteal resorption but had no effect on the endosteal apposition. ACTH had only minor effects on the endosteum. Thus, alpha-MSH and ACTH, in the doses used, have different effects on cortical bone in rat. The effect of alpha-MSH on cortical bone could be an effect of the hormone alone or by its stimulation of other factors.     

Antidiuretic hormone involvement in the release of alpha-melanocyte-stimulating hormone by hyperosmotic stimuli

In the normal Wistar rat, the plasma alpha-MSH level was raised by hypertonic saline injection (as compared with control rats injected with isotonic saline). No such rise in alpha-MSH followed hypertonic saline administration in the Brattleboro (hereditary diabetes insipidus) animal (compared to isotonic saline injected controls). It is suggested that, in the rat, endogenous antidiuretic hormone is involved in the secretory response of the pars intermedia to osmotic stimuli.     

Immunofluorescent localization of β-Corticotropin in the rat pituitary

Zusammenfassung Unter Verwendung eines spezifischen Anti-^1–24-Corticotropin-Serums vom Kaninchen wurde -Corticotropin immunhistologisch in der Rattenhypophyse nachgewiesen. Neben den Epithelien der Pars intermedia konnte kortikotropes Hormon in einem besonderen, mukoiden Zelltypus der Adenohypophyse lokalisiert werden.     

Endocrine cells producing regulatory peptides

Recent data on the immunolocalization of regulatory peptides and related propeptide sequences in endocrine cells and tumors of the gastrointestinal tract, pancreas, lung, thyroid, pituitary (ACTH and opioids), adrenals and paraganglia have been revised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory polypeptide), neurotensin, glicentin/glucagon-37 and PYY (peptide tyrosine tyrosine) are the main products of gastrointestinal endocrine cells; glucagon, CRF (corticotropin releasing factor), somatostatin, PP (pancreatic polypeptide) and GRF (growth hormone releasing factor), in addition to insulin, are produced in pancreatic islet cells; bombesin-related peptides are the main markers of pulmonary endocrine cells; calcitonin and CGRP (calcitonin gene-related peptide) occur in thyroid and extrathyroid C cells; ACTH and endorphins in anterior and intermediate lobe pituitary cells, alpha-MSH and CLIP (corticotropin-like intermediate lobe peptide) in intermediate lobe cells; met- and leu-enkephalins and related peptides in adrenal medullary and paraganglionic cells as well as in some gut (enterochromaffin) cells; NPY (neuropeptide Y) in adrenaline-type adrenal medullary cells, etc.. Both tissue-appropriate and tissue-inappropriate regulatory peptides are produced by endocrine tumours, with inappropriate peptides mostly produced by malignant tumours.     

Age-and sex-related development of ACTH in the pars distalis and neurointermedia of rat pituitary]

The content of ACTH of the pars distalis and neurointermedia of the pituitary of adult Rats is higher in the male than in the female. This differenciation of content, according to sex, appears at puberty at the site of pars distalis; it only appears around the 60th day of life at the site of the pars intermedia. The androgens seem to be responsible for the higher percentages observed in the males.     

Hypothalamic nerve fibres in the pars tuberalis and pia-arachnoid tissue of the cat and their degeneration pattern after a lesion in the hypothalamus

Zusammenfassung Mit der Bielschowsky-Gros-Methode wurden bei Katzen Nervenfasern untersucht, die vom Infundibulum in die Pars tuberalis ziehen. Die Befunde an normalen Tieren und an einer Katze mit einer Hypothalamus-Läsion zeigen, dass eine beachtliche Zahl hypothalamischer Fasern in verschiedene Teile der Pars tuberalis, sowie in das Gewebe der Pia und der Arachnoidea übergehen.Bei der operierten Katze wurde das Degenerationsbild der in den dorsalen Teil der Pars tuberalis ziehenden Hypothalamus-Fasern beschrieben.     

New histochemical contributions to the study of corticotropic cells in the adenohypophysis of the chick enbryo.]

Comparative analysis of results obtained after subsequent treatments of chick embryo adenohypophysis by anti-ACTH 17-39 Is, PAS and Bodian method demonstrates that ACTH cells are PAS positive, Bodian negative and are located in the cephalic lobe. With the histochemical fluorescence method of Falck, the cells marked by anti-ACTH 17-39 Is exhibit an induced fluorescence, after L-DOPA injection. However, after treatment by metopirone, numerous cells of the caudal part of the adenohypophysis take up L-DOPA but they are not corticotrophs.     

Relationship between the pars intermedia and the pars nervosa in the hypophysis of an antarctic seal

Resumen La pars intermedia de la hipófisis de la foca de Weddell (Leptonychotes weddelli) presenta trabéculas que irrumpen en la Pars nervosa. En estas trabéculas epiteliales se encuentran grumos y fibras de materialGömöri positivo. Este material no fué hallado en ninguna otra región de la adenohipófisis.

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This work has been carried out at the Scientific Station Almirante Brown in Antarctica during the Antarctic year 1966. It was supported by the Instituto Antártico Argentino. Contribución del Instituto Antártico Argentino No. 120.     

Naloxone prevents the analgesic action of alpha-MSH in mice

alpha-MSH (0.1, 1, 10 micrograms) was administered intracerebroventricularly and its action on pain sensitivity was investigated by the hot-plate method in mice. alpha-MSH produced dose-dependent analgesia and this analgesic effect was prevented by naloxone (1 mg/kg, s.c.). It is possible that alpha-MSH may play a role in the mechanism of pain through endogeneous opioid systems.     

Control of pituitary secretion of melanotropin in an anuran amphibian by thyrotropin releasing factor (TRH). Study in vitro]

Intermediate lobes from Rana esculenta pituitary glands were continuously superfused for 7 hrs at 28 degrees C with amphibian culture medium. alpha-MSH release was measured by use of a sensitive double antibody radio-immunoassay system. alpha-MSH secretion was inhibited by low temperatures. A large increase in alpha-MSH release was observed when Thyrotropin Releasing Hormone (TRH) at doses ranging from 10(-9) to 10(-7) molar was added to the superfusion medium. Since large amounts of TRH are to be found in the hypothalamus of amphibians but have no effect over pituitary TSH secretion, the action of TRH over alpha-MSH release may have a physiological significance.     

Monosynaptic inhibition of thalamic neurons produced by stimulation of the substantia nigra

Summary Electrical stimulation to the substantia nigra (Pars reticulata) produced a monosynaptic inhibition of the neurons of the ventromedial necleus of the thalamus in anesthetized cats.     

Disposition of the portal vessels of the avian pituitary in relation to the median eminence and the pars distalis

Zusammenfassung Die ermittelte Gefässversorgung der Vogelhypophyse beweist die Existenz eines doppelten Portalsystems der Pars distalis, womit auf zwei hypothalamo-hypophysäre Mechanismen hingewiesen wird.     

Stimulation by ACTH of protein synthesis in cultured adrenal cells. Absence of an effect by cyclin AMP]

ACTH stimulates the incorporation of 14C-leucine into proteins of adrenal tumor cells in culture. This stimulation though about 20% over controls is statistically significant. Cyclic AMP did not reproduce the stimulation observed with ACTH.