Effect of LH-RH peptide antagonist on serum LH, ovulation and menstrual cycle of crab-eating macaque

The effects of the antagonistic LH-RH analogue, D-(PHE2)-D-(ALA6)-LH-RH (Wy-18,185), were studied in the female crab — eating macaque (Macaca fascicularis) with emphasis on length of menstrual cycle, length and intensity of menstrual bleeding, serum LH, quantity and properties of cervical mucus, growth of the follicle and ovulation during the treatment and subsequent control cycles. Prior to the expected ovulation, the compound was administered subcutaneously, 25 mg/kg body weight/day, for 3 or 6 days. Blood was collected daily before, during and after treatment. Cervical mucus characteristics were charted daily. Laparoscopy was performed 2–4 days after presumed ovulation.