LHRH promotes the synthesis and release of a 87,000 Da protein (GP-87) by enriched gonadotrophs - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Molecular and Cellular Endocrinology Année : 1986

LHRH promotes the synthesis and release of a 87,000 Da protein (GP-87) by enriched gonadotrophs

Résumé

Protein secretion by cultured pituitary cells from 14-day-old female rats was estimated using [35S]methionine incorporation followed by either one- or two-dimensional electrophoresis and autoradiography. Stimulation of total cells or gonadotrophs by LHRH promoted the synthesis and release of a specific polypeptide (apparent molecular weight 87,000, pI = 4.6). Silver staining of cellular proteins from both gonadotroph-enriched and gonadotroph-depleted populations prepared by centrifugal elutriation revealed a high concentration of this polypeptide in the gonadotrophs and a very low level in the other cell population. This species was thus called Gonadotrope Polypeptide GP-87. Release of labeled GP-87 by gonadotrophs was both time dependent (up to 4 h) and LHRH dose dependent (from 10(-9) M to 10(-7) M) as was the release of LH. Attempts to precipitate GP-87 from the incubation medium with anti-LH antiserum were unsuccessful suggesting that GP-87 is not a 'big' form of LH. TRH neither stimulated the release of GP-87 from gonadotrophs nor from lactotrophs though it did stimulated PRL release. From these data, we conclude that gonadotrophs in culture synthesize a specific polypeptide (GP-87), LHRH stimulates both the synthesis and release of GP-87, and the pituitary cell response is peptide specific. The LHRH-induced synthesis and release of GP-87 could be an important step in the molecular processes that regulate gonadotrophin secretion.

Dates et versions

hal-01842094 , version 1 (17-07-2018)

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Eric Chanat, Jean-François Hubert, Benoît Sion, Mireille de Monti, Jacques Duval. LHRH promotes the synthesis and release of a 87,000 Da protein (GP-87) by enriched gonadotrophs. Molecular and Cellular Endocrinology, 1986, 46 (2), pp.109-119. ⟨10.1016/0303-7207(86)90089-4⟩. ⟨hal-01842094⟩
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