Effect of later treatment with estrogen on reproductive tract lesions in neonatally estrogenized female mice

Continuous ethinyl estradiol treatment following ovariectomy at day 38 of BALB cfC3H mice treated neonatally with estradiol resulted in a more organized vaginal epithelium than that seen in the absence of postnatal estrogen, 30 days after treatment was initiated. Although the epithelium became increasingly disorganized in all neonatally estrogenized groups with age, the later estrogen treatment reduced the incidence and severity of vaginal epithelial lesions and the incidence of vaginal concretions. Uterine epithelial metaplasia was accelerated by the later estrogen treatment.