Anovulatory luteal cycles in primates

The short-term therapy with gonadotropins and inhibitors of prostaglandin synthesis was administered to 12 adult cycling cynomolgus monkeys to study morphology and functions of anovulatory luteinized follicles. In Group 1, five monkeys (6 cycles) received human menopausal gonadotropin (hMG 10 I.U. FSH/10 I.U. LH per 1 kg) on cycle day (c.d.) 5 and 6. Human chorionic gonadotropin (hCG 50 I.U. per 1 kg) and hMG (5 I.U. LH and 5 I.U. FSH per 1 kg) were given at 12:00 on c.d. 7. Indomethacin (15 mg/kg) was injected at 16:30 on c.d. 7 and 08:30 on c.d. 8. Ovarian biopsy was obtained in 2 cycles. In Group 2, 7 monkeys (33 cycles) received single injection of hCG (50 I.U./kg) and hMG (5 I.U. FSH/5 I.U. LH/kg) four to one days before the expected ovulation. Two doses of Naproxen-sodium were given orally 4 and 20 hours later. After treatment, females were kept with males for 5 to 7 days. Laparotomy was performed one week after treatment. Ovarian biopsy was obtained in 5 cycles. Treatment in the midfollicular phase caused premature luteinization of the follicles and suppression of ovulation in all cycles. Histological studies revealed presence of luteinized follicles. Serum progesterone was elevated. Luteal phase averaged 13.6 days (vs. 15.8 days in ovulatory cycles). Treatment in the late follicular phase resulted in luteinization of the dominant follicle and inhibition of ovulation in 20 (61%) cycles. Luteal phase lasted 17.1 days. Serum progesterone was elevated to low or midluteal values. Gross evidence of ovulation was present in 13 (39%) cycles. One pregnancy occurred. All monkeys returned to regular, ovulatory cycles after the experiments were terminated.