Induction of luteal phase defects in rhesus monkeys by follicular fluid administration at the onset of the menstrual cycle

Administration of charcoal-extracted porcine follicular fluid (pFF) to rhesus monkeys on days 1-3 of the menstrual cycle suppressed serum FSH, but not LH, during the early follicular phase. Although timely midcycle gonadotropin surges occurred in 5 of 6 pFF-treated monkeys, the preovulatory rise in serum estradiol was markedly diminished and serum progesterone (P) levels were subnormal at midluteal phase. The wet weight of the corpus luteum excised from pFF-treated monkeys at midluteal phase was less than that from controls. Moreover, both basal and gonadotropin (hCG)-sensitive P production by short-term suspensions of luteal cells from pFF-treated monkeys was significantly less than that by control cells. These findings provide direct support for the concept that FSH-dependent events during the early follicular phase are important determinants of the subsequent function of the corpus luteum of the menstrual cycle. Since pFF-induced luteal dysfunction was strikingly similar to spontaneous luteal phase defects found in monkeys and women, this primate model permits study of the mechanism(s) whereby FSH deficiency during recruitment and selection of the dominant follicle portends defective luteal function and infertility in women.