Effect of GnRH antagonist, [Ac-delta 3Pro1, pFDPhe2, DTrp3,6] GnRH, on pulsatile gonadotrop in secretion in the castrate male primate.
Three different doses of a potent antagonist to GnRH, [Ac-delta 3Pro1, pFDPhe2, DTrp3,6], GnRH were compared in adult male monkeys to determine the acute effect on pulsatile gonadotropin secretion. In accomplishing these studies, blood was drawn at 15 min intervals over 24-30 h without anesthesia using a mobile vest and tether assembly to support an indwelling cannula. After a 3 to 6 h control period, 2.0, 0.2 or 0.02 mg GnRH antagonist/kg bw in 1 ml corn oil sc, was given to castrate adult monkeys. The highest dose decreased circulating LH (by radioimmunoassay and bioassay) and FSH whereas the intermediate dose decreased LH only. The higher dose produced both a more prolonged and greater reduction in circulating gonadotropins. These data demonstrate that this GnRH antagonist can reduce serum gonadotropins both acutely and for intervals greater than 24 h.
D000818:Animals; D002369:Castration; D004305:Dose-Response Relationship, Drug; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism*; D008253:Macaca mulatta; D008297:Male
D007987:Gonadotropin-Releasing Hormone; C036959:LHRH, Ac-dehydro-Pro(1)-4-F-Phe(2)-Trp(3,6)-; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone