Effect of gonadotrophin environment on growth and development of isolated mouse primary ovarian follicles.

Collagen gels containing isolated primary follicles devoid of other ovarian tissue were transferred beneath the kidney capsule of 3 types of female recipients: cycling, ovariectomized and hypogonadal, known to have different circulating concentrations of gonadotrophins. After 10 days the gels were recovered and processed for histology or the oocytes were recovered and their diameters measured and their ability to resume meiosis was determined. The growth of isolated primary follicles was positively correlated with the concentrations of circulating gonadotrophins in the recipient mice, but the numbers of oocytes recovered, the rate of oocyte growth and resumption of meiosis did not differ in the 3 types of recipient studied. This indicates that, in the conditions provided, oocyte growth was not related to the extent of follicular development.