Immunohistochemical study of the pars intermedia of the mouse pituitary in different experimental conditions

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

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.     

The relationship between human chorionic somato-mammotropine hormone and thyrostimuline in biological and radioimmunological assays

Résumé Les auteurs montrent qu'il n'existe pas d'inter-férences et de réaction croisée entre la thyréostimuline et l'hormone placentaire, la HCSM (human chorionic somato-mammotropine hormone) lors des déterminations respectives de ces hormones par test radioimmunologique. L'HCSM n'est donc pas responsable de l'augmentation de la TSH plasmatique observée au cours de la grossesse.     

Growth hormone resynthesis in the pituitary after depletion induced by a hypothalamic extract

Riassunto Lo studio della velocità di resintesi dell'ormone somatotropo nella ipofisi di ratto dopo la massiva deplezione indotta dalla somministrazione endocarotidea di un estratto di eminenza mediana dell'ipotalamo, ha messo in evidenza che 1 ora dopo la somministrazione il contenuto dell'ormone viene ricostituito in misura del 60%, 3 ore dopo sale all'80%, 5 ore dopo corrisponde ai valori normali.     

Differences in luteinizing hormone release stimulated in rat anterior pituitary cells by leukotriene C4 and by gonadotropin-releasing hormone in vitro

Summary Continuous administration of leukotriene C₄ (LTC₄, 10^–10 M) to superfused rat anterior pituitary cells increased LH release for 40 min only, whereas in a parallel experiment gonadotropin-releasing hormone (GnRH, 10^–9 M) evoked a continuous increase in hormone secretion. In contrast to GnRH, LTC₄ did not desensitize rat anterior pituitary cells. The secretory action resulting from the administration of LTC₄ (10^–10 M) was abolished for 40 min after previous stimulation. The results documented the dual action of LTC₄ on LH exocytosis.     

Differences in luteinizing hormone release stimulated in rat anterior pituitary cells by leukotriene C4 and by gonadotropin-releasing hormone in vitro

Continuous administration of leukotriene C4 (LTC4, 10(-10) M) to superfused rat anterior pituitary cells increased LH release for 40 min only, whereas in a parallel experiment gonadotropin-releasing hormone (GnRH, 10(-9) M) evoked a continuous increase in hormone secretion. In contrast to GnRH, LTC4 did not desensitize rat anterior pituitary cells. The secretory action resulting from the administration of LTC4 (10(-10) M) was abolished for 40 min after previous stimulation. The results documented the dual action of LTC4 on LH exocytosis.     

Passage of pituitary hormones through the nephrotic rat kidney and its possible biological significance

Zusammenfassung An Ratten mit experimentell erzeugter Proteinurie wurde gezeigt, dass das bovine thyreotrope Hormon nach i.v. Injektion von der geschädigten Niere in kurzer Zeit ausgeschieden wird. Die Versuche stützen die These, dass dem Verlust von hypophysären Hormonen in der Pathogenese von endokrinen Störungen bei Eiweissverlustsyndromen beträchtliche Bedeutung zukommt.     

Sequence comparison of human pituitary growth hormone,human chorionic somatomammotropin and ovine pituitary lactogenic hormone

Zusammenfassung Ein Vergleich der Aminosäuresequenzen von menschlichen Wachstumshormonen und menschlichem Chorion-Somatomammotropin mit denjenigen von Prolactin zeigt, dass 26% des Rückstandes in allen drei Molekülen die gleiche Position hatten mit zusätzlichen 34% als möglichen Ersatz. Alle drei Hormone scheinen einen gleichen Ursprung zu haben.     

Estimation of plasma thyroxine concentration in ducks in relation to different environmental and experimental conditions

Summary Plasma thyroxine concentration was measured in ducks by the thyroxine-binding globulin technique. The assay allowed us to detect annual variations in thyroid activity as well as significant changes after starvation or cold exposure. No detectable thyroxine was formed in surgically thyroidectomized ducks.Supproted by CNRS and the Department of Biology of the CEA.     

Laccase production byPolyporus sanguineus under different nutritional and environmental conditions

Summary Laccase production was higher in malt extract medium than in lignin, andPolyporus sanguineus appears to be better thanPolyporus versicolor andTrametes hirsuta (syn.Polyporus hirsutus) for enzyme production. Phenolic compounds, of which resorcinol was the most active, induced enzyme production; while sugars repressed it. A temperature of 37°C, pH 3 and indulin AT at a concentration of 0.2% gave the best enzyme yield.A part of Ph. D. thesis of D.S. Arora.Acknowledgments. We thank Westvaco Chemical Division, USA, and Dr P.S. Rehill, Forest Research Institute, Dehradun, India for providing lignin samples and the fungal strain, respectively. D.S. Arora further thanks University Grants Commission, New Delhi for financial assistance.     

Adenyl cyclase activity at different environmental temperatures in the isolated rat anterior pituitary membranes

Summary The effect of different environmental temperatures on adenyl cyclase was studied. An increase in temperature appears to increase TRH-induced activity of adenyl cyclase, and possibly causes an increased sensitivity to the hormone. Cyclic AMP levels of the pituitaries showed change at different environmental temperatures.