The Relationship between Endocrine Imbalance and Alteration of Rat Vaginal Epithelium

The relationship between endocrine imbalance and vaginal epithelial features in rats was examined in aging Donryu and F344 rats, pregnant and lactated Donryu rats, and antipsychotic agent-treated Wistar rats. In addition, the influence of sex steroid hormones and prolactin secretion due to haloperidol administration and pituitary implantation was also investigated in ovariectomized Donryu females. Vaginal cornification and mucification were found to be linked with relatively high 17 β-estradiol (E2) levels and the relatively high progesterone (P) value under higher E2 concentration, respectively. Under ovariectomized conditions, the degree and incidence of vaginal mucification were emphasized by P and E2, being dose-dependency of E2. Mucification of the vaginal epithelium by antipsychotic agents might be induced by high P value through the effect of corpus stimulation by prolactin. These results indicated that the vaginal epithelium of rats is very sensitive to hormonal imbalance, and its morphological features are very useful for the assessment of individual hormone milieu.