Reproductive endocrine effects of intranasal administration of norethisterone to adult female rhesus monkeys (Macaca mulatta).
Intranasal administration of norethisterone at a daily dose of 9 micrograms between Days 5 and 14 of the menstrual cycles blocked ovulation in 10 out of 17 adult female monkeys. Serum concentrations of hormones indicated that ovulation was blocked due to a suppression of the mid-cycle, oestradiol-induced LH surge. Ovarian follicular activity in the treated menstrual cycles was not affected by norethisterone but there was a marked delay in the onset of the mid-cycle oestradiol surge in most of the treated animals. The duration of the menstrual cycle length after the oestradiol peak was significantly reduced in all the treated monkeys, indicative of a shortened luteal phase.
D000281:Administration, Intranasal; D000818:Animals; D004958:Estradiol / Q000097:blood; D005260:Female; D007986:Luteinizing Hormone / Q000378:metabolism*; D008251:Macaca; D008597:Menstrual Cycle; D009640:Norethindrone / Q000008:administration & dosage* / Q000494:pharmacology; D006080:Ovarian Follicle / Q000187:drug effects; D010060:Ovulation / Q000187:drug effects*; D011374:Progesterone / Q000097:blood
D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D009640:Norethindrone