Oestrogen induced uterine damage in rats

The present study was undertaken to assess the oestrogen induced uterine damage in albino rats. Ethinyl oestradiol (EO) as a semisynthetic oestrogen was administered to the rats of groups 2, 3 and 4 @ 250, 500 and 750 ?g/kg body weight, respectively orally once a week for 8 weeks. The same doses of EO were administered to the rats of groups 5, 6 and 7, respectively for 12 weeks. On the 9th week, vacuolar degeneration of columnar epithelial cells in the mucosa and endometrial glands was observed in rats of groups 2 to 4. The blood vessels in the endometrium were dilated and congested. In group 3, the necrosis and desquamation of epithelial cells were also evident. At certain places, proliferation of fibrovascular connective tissues was distinct in groups 3 and 4. The degeneration and necrosis of mucosa and endometrial gland with infiltration of inflammatory cells were marked in group 4. On the 13th week, these changes were more marked in the respective group. The extent and severity of uterine damage were found to be dose and time dependent, which indicated that at higher dose and prolonged period, EO (oestrogen) causes severe damage in the uterus. EO has produced the optimum and standard uterine damage at the dose of 750 ?g/kg, orally weekly for 12 weeks.