EFFECT OF LONG-TERM CYCLIC ORAL ADMINISTRATION OF ENOVID ON THE GENITAL ORGANS OF PREPUBERAL FEMALE RHESUS MONKEYS.

The effect of Enovid (10 mg) administered for 90-1095 days on the genital organs of prepuberal female rhesus monkeys was studied. The only significant effect on the ovaries was a consistent increase in weight. Follicular development was unimpeded and Graafian follicles were apparent towards the end of treatment. There was little effect on the number of primordial oocytes. Enovid had virtually no effect on pituitary gonadotropic activity though such activity is minimal in the prepuberal rhesus monkey. The drug did not inhibit the normal prepubertal surge of gonadotropin activity. Generally changes in the endometrium as well as the cervix though not adverse were disordered variable and unpredictable. Withdrawal bleeding was observed at the end of the monthly regimen. Breakthrough bleeding was observed in only 3 animals during the course of the study. Development of the circumgenital skin and breasts was enhanced by the treatment. There was a slight stimulation of adrenocortical activity though the response of the thyroid was ambiguous. The results indicate that Enovid does not produce any abnormal changes in the genital tract of the prepuberal rhesus monkey nor does it interfere with normal sexual development.