THE EFFECT OF THE FOLLICULAR HORMONE ON OLD ALBINO RATS

Abstract

Cornified cells were found in vaginal smears in 9 rats after they had passed the menopause or had ceased to mate. These cells often persisted for 1-4 days. Oestrual changes in the vaginal mucosa were produced by smaller doses of the hormone than those required to incite mating. One or 2 injections had little or no effect in modifying oestrual rhythm or in inciting mating in rats nearing the menopause unless the injections coincided with a normal appearance of cornified cells. Nine injections in ovariectomized rats 719 days old caused a single appearance of cornified cells lasting 2-4 days. The results indicate that the effect of the injected hormone in old rats is but transitory, does not prolong productive sexual life by inciting ovulation, but may temporarily stimulate mating activities.