Inhibition of CRF- and urotensin I-stimulated ACTH release from goldfish pituitary cell columns by the CRF analogue alpha-helical CRF-(9-41).
alpha-Helical CRF-(9-41) is an analogue of corticotropin-releasing factor (CRF) that antagonizes CRF-stimulated ACTH release in rats. In the present study, alpha-helical CRF-(9-41) was tested to determine whether it would antagonize the ACTH-releasing activity of CRF or urotensin I (UI) observed with superfused, dispersed goldfish anterior pituitary cells. At a concentration of 4 microM, alpha-helical CRF-(9-41) completely blocked the ACTH-releasing activity of 100 nM CRF or 100 nM UI. The inhibitor by itself showed little intrinsic ACTH-releasing activity. This investigation reveals similarities in the CRF-antagonism of alpha-helical CRF-(9-41) in the teleost and mammalian pituitary in vitro. It also provides are similar and suggests that alpha-helical CRF-(9-41) may be useful as a tool to investigate the effects of CRF-like and UI-like peptides in teleost fishes.
Weld
M M
MM
Department of Anatomy, Faculty of Health Sciences, University of Ottawa, Ont., Canada.
Fryer
J N
JN
Rivier
J
J
Lederis
K
K
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors* / Q000494:pharmacology* / Q000502:physiology; D003530:Cyprinidae / Q000378:metabolism*; D006054:Goldfish / Q000378:metabolism*; D066298:In Vitro Techniques; D010446:Peptide Fragments / Q000494:pharmacology*; D010455:Peptides / Q000037:antagonists & inhibitors*; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D014579:Urotensins / Q000037:antagonists & inhibitors* / Q000502:physiology
D010446:Peptide Fragments; D010455:Peptides; D014579:Urotensins; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; C029676:urotensin I; C045089:corticotropin releasing hormone (9-41)