INFLUENCE OF A GONADOTROPIN-RELEASING-HORMONE AGONIST AND GONADOTROPINS ON MORPHOMETRIC CHARACTERISTICS OF THE POPULATION OF SMALL OVARIAN FOLLICLES IN CYNOMOLGUS MONKEYS (MACACA-FASCICULARIS)

Small follicles, less-than-or-equal-to 100-mu-m, in monkey ovaries were divided into four types based on the morphological characteristics of the granulosa cells that surrounded the oocyte: primordial, intermediary, primary and secondary follicles. The proportion of primordial follicles positively correlated, whereas those of intermediary, primary and secondary follicles negatively correlated, with the total number of follicles less-than-or-equal-to 100-mu-m. There was no relationship between the population of nongrowing follicles (primordial and intermediary) and that of early-growing follicles (primary and secondary). Administration of exogenous gonadotrophins did not induce significant changes in the population of small follicles, whereas there was a significant increase in the number of intermediary follicles when gonadotrophins were associated with a gonadotrophin-releasing hormone agonist, buserelin. Buserelin can therefore partly inhibit the initiation of ovarian follicular growth in monkeys.