LUTEINIZING-HORMONE-RELEASING HORMONE AGONIST INHIBITS CYCLOPHOSPHAMIDE-INDUCED OVARIAN FOLLICULAR DEPLETION IN RHESUS-MONKEYS

Several investigators have demonstrated that LHRH agonists (LHRHa) inh ibit ovarian follicular depletion induced by chemotherapeutic agents i n rodents. It is not clear whether or not the same effects occur in pr imates. Six adult female rhesus monkeys underwent unilateral ovariecto my and were divided into two groups that received monthly injections o f either Lupron depot (LHRHa) or placebo vehicle. Both groups received cyclophosphamide (CTX) injections. Weekly blood samples were assayed for FSH, estradiol and progesterone. Mean serum FSH levels significant ly increased in the CTX group and significantly decreased in the LHRHa +CTX group. At the end of treatment, the remaining ovary was removed a nd serially sectioned, and ovarian follicle number and size were analy zed. CTX resulted in a significant reduction of nonprimordial follicle s < 50 mu m in diameter. The rate of loss of primordial follicles was expressed as a percentage of the original follicle count. During the t reatment period, 64.6 +/- 2.8% of the total primordial follicles were lost in the CTX group compared to only 28.9 +/- 9.1% in the LHRHa+CTX group (p < 0.05). The percentage rate of decline per day was 0.120 +/- 0.012 for the CTX group compared to 0.057 +/- 0.019 (p < 0.05) for th e LHRHa+CTX group. The findings indicate that LHRHa can protect the ov ary against CTX-induced damage in rhesus monkeys.