Stimulation of androstenedione and progesterone release by LHRH and LHRH agonist from isolated rat preovulatory follicles.
Incubation of preovulatory rat follicles isolated from PMSG-treated immature rats for periods of less than 24 h in the presence of LHRH or LHRH agonist resulted in stimulation of basal androstenedione and progesterone release. The stimulatory effects seen were time-dependent, occurring from 2-3 h for androstenedione and from 8-20 h incubation for progesterone. Dose-dependent stimulation occurred with both LHRH agonist (in the range 5 X 10(-10) to 10(-8) M) and native LHRH (from 10(-9) to 10(-6) M), both being in the range of the reported Ka for ovarian LHRH receptors. LHRH did not enhance the stimulatory effect of 1-100 mIU hCG on androstenedione and progesterone release. These results show for the first time that LHRH and LHRH agonist can exert a stimulatory action on androgen release from isolated preovulatory follicles. This suggests that LHRH may be acting either directly at the thecal cell level or indirectly via decreased granulosa cell aromatization.
D000735:Androstenedione / Q000378:metabolism*; D000818:Animals; D002064:Buserelin; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006080:Ovarian Follicle / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D006063:Chorionic Gonadotropin; D007987:Gonadotropin-Releasing Hormone; D000735:Androstenedione; D011374:Progesterone; D002064:Buserelin