Effect of hormonal replacement therapy on the vaginal epithelium of ovariectomized rats

The present study was planned to clarify the effect of replacement therapy of estrogen and progesterone on ovariectomized rats. 49 adult female albino rats each weighing 200-250 grams were utilized in this study. The animals were divided into two major groups, the first group served as control group, it was further subdivided into three subgroups, subgroup Ia comprised the non ovariectomized female rats which received no treatment, subgroup Ib, sham operated group animals, subgroup Ic: received 0.1 ml olive oil i.m once per day for two consecutive days after 4 weeks of ovariectomy and served as control for estrogen and progesterone treated groups. The second group was subdivided into 4 subgroups. Subgroup IIa: included ovariectomized rats, subgroup IIb: ovariectomized rats treated with progesterone 12.5 mg/kg. Subgroup IIc: ovariectomized rats treated with estrogen 0.38 mg/kg. Subgroup IId: ovariectomized rats received combined treatment of both estrogen and progesterone. The non ovariectomized rats were sacrificed at oestrus cycle as denoted by daily vaginal smear, while the remaining groups were sacrificed after 4 weeks of ovariectomy by 48 hours, both light and scanning electron microscopy were performed. Results showed that exogenous progesterone increased mucosal folding with short bulb or rosette shaped microvilli. Estrogen resulted in epithelial cell proliferation and keratinization. Cell separations were obvious in some areas indicating desquamation. The combined treatment demonstrated morphological picture nearly similar to oestrus cycle. Hence, it is wise to use the combined treatment as denoted by inhibition of excessive vaginal epithelial proliferation and cornification