Inhibition of the primate ovarian cycle by a porcine follicular fluid protein(s)

Monkeys received twice daily intramuscular injections of 3 mg of purified porcine follicular fluid protein(s) for the first 14.5 days of the menstrual cycle. Two of five treated monkeys had anovulatory menstrual cycles. Three monkeys had cycles characterized by long follicular phases, low follicular and luteal phase serum estradiol concentrations, and subnormal luteal progesterone production. Serum gonadotropin concentrations were not affected by the follicular fluid protein(s). The data demonstrate in the nonhuman primate that porcine follicular fluid contains a protein(s) that acts at the ovarian level to inhibit gonadotropin action.