Bombesin regulation of adrenocorticotropin release from ovine anterior pituitary cells.
Mammalian members of the bombesin-like peptide family (gastrin releasing peptides; GRP) have been localized in the ovine median eminence and in hypophysial-portal blood, suggesting a role in the regulation of anterior pituitary function. In this study we have shown that although bombesin cannot stimulate ACTH secretion alone, it potentiates release by ovine CRF, an effect blocked by the GRP receptor antagonist D-Tyr6bombesin (6-13) propylamide. Bombesin did not potentiate AVP-stimulated ACTH release; instead release was attenuated when bombesin was given at a 10-fold or greater molar excess over AVP, with no interaction seen at lower concentrations. We conclude that ovine corticotrophs express bombesin receptors, and that GRP may act in concert with other hypothalamic releasing factors to regulate ACTH secretion.
Au
C L
CL
Department of Medicine, University of Melbourne, Western Hospital, Footscray, Australia.
Canny
B J
BJ
Farnworth
P G
PG
Giraud
A S
AS
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D001839:Bombesin / Q000494:pharmacology*; D002478:Cells, Cultured; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D004347:Drug Interactions; D019886:Gastrin-Releasing Peptide / Q000494:pharmacology; D066298:In Vitro Techniques; D010446:Peptide Fragments / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000187:drug effects* / Q000378:metabolism*; D018004:Receptors, Bombesin / Q000037:antagonists & inhibitors; D012756:Sheep
D010446:Peptide Fragments; D018004:Receptors, Bombesin; D001127:Arginine Vasopressin; D019886:Gastrin-Releasing Peptide; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D001839:Bombesin