Release of immuno-reactive and biologically active LH from fetal mouse pituitary in response to synthetic gonadotropin releasing factor (LRF).

In an incubation system, LRF stimulated significantly the release of LH from 18-day-old mouse fetal pituitary. This LRF-induced LH release, measured by RIA in the incubation medium was able to increase the testosterone production by age-matched fetal testes. This data suggests that the hypothalamo-hypophyseal-testicular axis is functional at the end of mouse prenatal life.     

Cytological effect of gonadotropin releasing factor activity from beef hypothalamic extract of the pituitary cells in vitro

Zusammenfassung Untersuchungen an spezifisch gefärbten Serienschnitten von Adenohypophysenfragmenten, die mit Rinderhypothalamusextrakten — inkubiert wurden, zeigten eine deutliche Zunahme von Sekretgranula der gonadotropen Zellen, Bildung von Vakuolen und Degranulationsbeginn.     

Solubility of the hypothalamic hormones TSH-releasing factor (TRF) and LH-releasing factor (LRF) in organic and alcoholic solvents

Résumé L'hormone hypothalamique TRF (TSH-releasing factor) est soluble dans l'alcool méthylique à 90%, partiellement soluble dans l'alcool méthylique absolu ou le chloroforme; TRF n'est pas soluble dans la pyridine. Le chlorure de méthylène (dichlorométhane) n'extrait pas le TRF d'une solution aqueuse (préparation hautement purifiée, 15000 U/mg). L'hormone hypothalamique LRF (LH-releasing factor) n'est pas soluble dans le chloroforme mais est soluble dans l'alcool méthylique absolu ou à 90%.

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Supported by U.S.P.H.S. research grants No. AM 08290.03, No. HD 02577.01, training grant No. GM 956.04; also No. FR 00254 to Common Research Computer Facility, Texas Medical Center.     

Epidermal growth factor (EGF) accelerates the maturation of fetal mouse intestinal mucosa in utero

Summary Pregnant Swiss ICR mice were injected i.p. with 0.5 g of epidermal growth factor (EGF) per g b. wt at 15, 16 and 17 days of gestation and fetuses were removed at 18 days of gestation. EGF treatment had no effect on the weight of the fetuses and on the length of the small intestine. No modification of the protein and DNA contents was noted. However brush border alkaline phosphatase and trehalase activities were significantly increased as well as endoplasmic reticulum membrane-bound glucose-6-phosphatase.Supported by grant MA-6069 from the Medical Research Council of Canada. Dr D. Ménard is a chercheur boursier du Fonds de la recherche en santé du Québec     

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.     

Pituitary gonadotropin releasing hormone (GnRH) receptor levels in intact and ovariectomized-adrenalectomized female golden hamsters on a short photoperiod

Both intact and ovariectomized + adrenalectomized hamsters on a short photoperiod, had a daily surge in plasma LH at approximately 16.00-18.00 h. The number of pituitary GnRH receptors was generally lower in ovariectomized + adrenalectomized hamsters than in intact animals, but both intact and ovariectomized + adrenalectomized hamsters had a decrease in the number of receptors just prior to the LH surge. These results show that gonadal steroids are not involved in regulating the pre-LH surge fall in the number of GnRH receptors.     

Pituitary gonadotropin releasing hormone (GnRH) receptor levels in intact and ovariectomized-adrenalectomized female golden hamsters on a short photoperiod

Summary Both intact and ovariectomized+adrenalectomized hamsters on a short photoperiod, had a daily surge in plasma LH at approximately 16.00–18.00 h. The number of pituitary GnRH receptors was generally lower in ovariectomized+adrenalectomized hamsters than in intact animals, but both intact and ovariectomized+adrenalectomized hamsters had a decrease in the number of receptors just prior to the LH surge. These results show that gonadal steroids are not involved in regulating the pre-LH surge fall in the number of GnRH receptors.     

Immunocytochemical localization of GnRH (gonadotropin releasing hormone) systems in the brain of a marine teleost fish,the sole

Summary The GnRH system was studied in the brain of the sole by immunocytochemistry (peroxidase-antiperoxidase method) (PAP) using antibodies to synthetic salmon GnRH (s-GnRH). Two centers containing immunoreactive cell bodies were observed in the forebrain, one located at the junction between the olfactory bulbs and the telencephalon and the other in the preoptic area. Numerous immunoreactive fibers were found, especially in the telencephalon, hypothalamus, pituitary, optic tectum and retina.     

Immunofluorescent localization of beta-lipotropin (beta-LPH) and beta-endorphins in normal and anencephalic human fetal pituitary gland]

The use of antibodies to alpha-(17-39) ACTH, beta-LPH, alpha- and beta-endorphins has enabled the detection of immunoreactive cells in human fetal pituitary glands as early as the eight week of gestation. The same cells reacted with the different antibodies. Immunoreactive cells were also observed in the pituitary of 6 human anencephalic fetuses.     

The evaluation of biologically active supernatants of cultures of lymphoid cells from rabbits with delayed (cellular) hypersensitivity on a macrophage layer

Zusammenfassung Supernatanten aus Kulturen überempfindlicher Lymphozyten und dem spezifischen Antigen mit MIF-Aktivität können die Entstehung der Pseudopodien normaler Makrophagen verhindern und zeigen nach längerem Kultivieren zuweilen toxische Eigenschaften.     

Age dependency of the primary immune response in the hereditary pituitary dwarf and normal snell-bagg mouse

Riassunto Vengono riportati i dati relativi allo sviluppo in funzione dell'età, della reatività immunologica primaria nel topo con nanismo ereditario preipofisario e nel corrispondente fratello normale. Mentre in quest'ultimo si è notato un graduale incremento della reattività immunitaria di tipo primario soprattutto a partire dalla fine del periodo di allattamento, nel topo nano la reattività immunitaria primaria è rimasta costante nel tempo su bassi livelli anche dopo lo svezzamento. Alla luce dei dati sperimentali riportati viene ipotizzata l'esistenza di un controllo ipofisario della reattività immunitaria primaria.     

Effects of a bovine pineal peptidic fraction (E5) on plasma and pituitary levels of LH,FSH and prolactin

Summary Pituitary levels of prolactin were significantly diminished after 5 s.c. injections spaced 12 h apart of 5 g of a partially purified bovine pineal peptide fraction (E₅) in both intact and castrated rats. E₅ treatment did not significantly affect the castration-induced changes in plasma luteinizing hormone (LH), follicle-stimulating hormone (FSH) or pituitary LH but did partially block the pituitary fall in FSH in castrated animals.Supported by NSF grant PCM 8003441 and NIH Center for Reproductive Biology (Bioassay Core) No.P30 HD 10202. Many thanks are due A. Moreno for his excellent technical assistance.