Inhibition of folliculogenesis in the monkey following early follicular phase administration of an LRH agonist

Publisher Website
Google Scholar
Abstract
To determine if early follicular phase administration of a synthetic LHRH agonist would produce luteal phase defects in the rhesus monkey. [D-His-(im-Bzl)6,Pro9]LHRH N-ethylamide was administered to groups of rhesus monkeys on days 1-3 of the menstrual cycle. Two responses were observed: anovulatory menstrual cycles of less than 14 days duration, and ovulatory menstrual cycles characterized by unusually long follicular phases. All 4 monkeys with shortened menstrual cycles had prominent increases in serum gonadotropin and estradiol concentrations during treatment with the LHRH agonist: early menses in these animals was attributed to uterine bleeding upon estrogen withdrawal. Serum FSH concentrations declined, serum luteinizing hormone [LH] concentrations were unaltered, and only 2 of 8 monkeys had elevations in serum estradiol during ovulatory menstrual cycles. The mean interval from cessation of treatment with the LHRH agonist to the next preovulatory gonadotropin surge was 21.5 .+-. 3.2 days in ovulatory menstrual cycles. Corpus luteum function was normal following treatment with the LHRH agonist in ovulatory cycles. Both the long and short menstrual cycles observed following early follicular phase administration of the LHRH agonist to monkeys can be attributed to a profound inhibition in follicle recruitment. [D-His(im-Bz)6,Pro9]LHRH N-ethylamide did not alter corpus luteum function in the monkey.