title: Inhibitory activity of four analogs of luteinizing hormone-releasing hormone in vivo.
abstract: Four analogs of luteinizing hormone-releasing hormone (LH-RH), [des-His2,D-Ala6]-LH-RH, [des-His2,D-Ala6, des-Gly-NH2(10)1-LH-RH ethylamide, [des-His2,D-Leu6]-LH-RH, and [D-Phe2,D-Leu6]-LH-RH, at 300-fold molar ratios (analog/LH-RH) led to an almost complete inhibition of LH response to LH-RH in anesthetized 4-day cycling rats on the afternoon of proestrus. At a 75-fold molar ratio, [des-His2,D-Ala6]-LH-RH still inhibited the LH-RH-induced LH release by 50%. The ethylamide substitution at the COOH terminus of [des-His2,D-Ala6]-LH-RH did not significantly improve the inhibitory activity of the molecule.
mesh_terms: D000818:Animals; D004971:Estrus; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000037:antagonists & inhibitors*; D011247:Pregnancy; D011863:Radioimmunoassay; D051381:Rats
chemical_list: D006728:Hormones; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone