title: Post-coital contraceptive effects of an agonistic analogue of luteinizing hormone releasing hormone.
abstract: An analogue of synthetic hypothalamic LRH, D-[ALA]6-DES-[GLY]10-PRO9-ethylamide-LRH (Wy-18,481) was evaluated for agonistic (in vivo LH-releasing and ovulation-inducing), post-coital contraceptive and reproductive target organ effects. Both LRH and the analogue terminated pregnancy; there appeared to be a direct relationship between agonistic and post-coital contraceptive potency and activity. The analogue proved to be a potent agonist and both a pre-and post-implantational post-coital anti-fertility agent. In contrast to LRH, the congener did not produce a uterotrophic effect in the hypophysectomized rat. The data suggest that agonist analogue(s) of LRH can terminate pregnancy via hyperstimulation of the pituitary-ovarian-reproductive complex and the use of members of this neurohormonal class as potential clinical pro-fertility agents should be weighted with caution.
mesh_terms: D000818:Animals; D003281:Contraceptives, Postcoital / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology; D051379:Mice; D009929:Organ Size; D010060:Ovulation / Q000187:drug effects; D011247:Pregnancy; D011817:Rabbits; D051381:Rats; D014599:Uterus / Q000033:anatomy & histology
chemical_list: D003281:Contraceptives, Postcoital; D006728:Hormones; D007987:Gonadotropin-Releasing Hormone