Effects of intrafollicular administration of gonadotropins in two species of nonhuman primates using laparoscopy.

Direct administration of 0.5 IU of human chorionic gonadotropin (HCG) into the matured ovarian follicles of adult female Saimiri sciureus resulted in ovulation in 45% of the animals treated. When purified ovine luteinizing hormone (LH) was administered, ovulation was observed in 55% of the animals while intrafollicular injection of saline had no effect. Similar injections of HCG into matured follicles of Macaca fascicularis would not cause ovulation but did result in a 55% increase in menstrual cycle length. These results indicate that the necessity of a primate source of LH for inducing ovulation may be due to an extrafollicular mechanism.