Negative feedback effects of oestradiol-17 beta on luteinizing hormone in female rhesus monkeys under different seasonal conditions.
Suppression of luteinizing hormone (LH) by sc implanted oestradiol-17 beta (E2) pellets was examined in 4 ovariectomized female rhesus monkeys during the breeding season, the non-breeding season and during the transition between the breeding and non-breeding season. Immunoreactive LH was suppressed to 58, 78 and 75% of untreated levels for the respective seasonal conditions. Bioactive LH was suppressed to 29, 49 and 33% of baseline. Bioactive LH (determined by testosterone release from rat interstitial cells) was significantly correlated (r = 0.84) with immunoactive LH from the same samples. It is concluded that E2 treatment of ovariectomized female rhesus monkeys results in suppressed levels of LH, regardless of the time of year.
D000818:Animals; D002369:Castration; D004343:Drug Implants; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D005246:Feedback; D005260:Female; D007986:Luteinizing Hormone / Q000097:blood*; D008253:Macaca mulatta; D012621:Seasons
D004343:Drug Implants; D004958:Estradiol; D007986:Luteinizing Hormone