Effect of a potent gonadotropin releasing hormone antagonist on pulsatile testosterone and gonadotropin secretion in the male nonhuman primate.
A potent gonadotropin releasing hormone (GnRH) antagonist [Ac-delta 3Pro1, pFDPhe2, DTrp3,6]-GnRH was given to adult male monkeys to determine the acute effect on pulsatile testosterone and gonadotropin secretion. Blood was drawn at 30 min intervals over 54 h without anesthesia using a mobile vest and tether assembly to support an indwelling catheter. After a 6 h control period, 0.1, 1.0, 2.0, 4.0 mg GnRH antagonist/kg bw in 1 ml corn oil sc, was given to intact adult male monkeys. The highest dose of GnRH antagonist decreased circulating testosterone within 6 h and for approximately 24-36 h duration. These data demonstrate that this GnRH antagonist can reduce serum testosterone both acutely and for intervals greater than 24 h and that the effective dose in intact animals is several-fold (up to 20 times) greater than in castrate animals.
D000818:Animals; 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*; D008252:Macaca fascicularis; D008297:Male; D013739:Testosterone / Q000378:metabolism*; D013997:Time Factors
D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; C037281:LHRH, Ac-delta(3)-Pro(1)-4-F-Phe(2)-Trp(3)-Lys(6)-; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone