title: The effect of GHRH on TSH release in rats in vivo and in vitro.
abstract: In man, GHRH has been shown to potentiate the TSH-releasing activity of TRH. To study the way by which GHRH affects TRH-stimulated TSH release, we examined the effect of GHRH (1-29)NH2 on basal and stimulated TSH secretion in intact male rats and superfused dispersed rat pituitary cells. In the intact rats, GHRH(1-29)NH2 potentiated TRH-stimulated TSH release in the evening, but potentiation was not observed in the morning and in dispersed pituitary cells. Basal TSH levels were not changed by GHRH(1-29)NH2. It is concluded that GHRH(1-29)NH2 potentiates the TSH-releasing activity of TRH in the evening in rats possibly through suprahypophyseal disinhibition.
authors.affiliation: Department of Endocrinology, University Hospital, Leiden, The Netherlands.
authors.forename: B J
authors.initials: BJ
authors.lastname: Looij
authors.forename: A C
authors.initials: AC
authors.lastname: Nieuwenhuijzen Kruseman
authors.forename: F
authors.initials: F
authors.lastname: Roelfsema
authors.forename: D
authors.initials: D
authors.lastname: van der Heide
authors.forename: R P
authors.initials: RP
authors.lastname: Hoogma
authors.forename: J P
authors.initials: JP
authors.lastname: Schröder-van der Elst
mesh_terms: D000818:Animals; D004357:Drug Synergism; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013972:Thyrotropin / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology
chemical_list: D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin; D013007:Growth Hormone-Releasing Hormone