No abstract

Histological and immunohistochemical changes in vaginal tissue structure of ovariectomized rats were assessed in response to sex steroid hormone administration. Sixty female rats were divided into six groups (10) each; control, sham, ovariectomized, ovariectomized rats treated with estradiol (20 µg/kg/day), Ovariectomized rats treated with progesterone (1 mg/kg/day) and ovariectomized rats treated with both estradiol and progesterone. Vaginal tissues were examined through haematoxylin and eosin, masson trichrome, and periodic acid shiff stains. Immunohistochemistry was used for expression of E-cadherin in vaginal epithelial cells. Ovariectomized rats with or without progesterone administration revealed a significant decrease in vaginal weight and length, reduction of vaginal epithelial thickness and glycogen content, which were restored with estradiol administration. Percent area of collagen fibers was not affected in all groups. E-cadherin expression was decreased in vaginal epithelium of both ovariectomized rats and progesterone administered group. It was concluded that vaginal epithelial atrophy due to ovariectomy can be restored by administration of estradiol or in combination with progesterone.

Major salivary glands are characterized by the presence of numerous excretory units that consist of acini and a peculiar duct system. The excretion of saliva is assisted by the myoepithelial cells which play an important role in the morphology of several kinds of salivary gland tumors (Martinez-Madringal and Micheau, 1989). Although the rat salivary glands are deficient in acini at birth, acinar cells proliferate rapidly during the early postnatal period (Klein, 1982).