Original Article

Oestradiol which induces the proliferation of the vaginal epithelium is used in the oestrogen replacement therapy for menopausal and postmenopausal disorders. The exact onset of induced cell proliferation and recovery to the controlled level has not been reported before. Hence this study was done in ovariectomised mice and the period of cellular response to ethinyl estradiol, a semisynthetic ester (0.025mg/kg) was recorded. The vaginal epithelium was studied for histological changes and incidence of mitotic figures. The onset of proliferation started at 4h after exposure and reached its maximum at 32h and declined gradually thereafter to reach the base level at 60h