Nature of Induced Persistent Vaginal Cornification in Mice. IV. Changes in the Vaginal Epithelium of Old Mice Treated Neonatally With Estradiol or Testosterone2

Abstract

BALB/cCrgl female mice were treated with different doses of estradiol or testosterone for the first 5 days of life. Some mice in each group were ovariectomized at 110–120 days of age, and all mice were killed at 15–17 months of age. Vaginas, uteri, ovaries, adrenals, and mammary glands were examined, and the long-term effects of neonatal steroid treatment on these organs are described. Hyperplastic epithelial lesions resembling epidermoid carcinomas were found in the vaginas of both intact and ovariectomized mice treated with either steroid at dose levels associated with the induction of ovary-independent persistent vaginal cornification, although ovariectomy reduced the incidence of such lesions. Vaginal lesions also occurred in intact mice with ovary-dependent persistent estrus, but not in ovariectomized mice from these groups that had been treated with low steroid doses. It was concluded that the development of hyperplastic changes in the vaginal epithelium depends on factors which also control the development of persistent cornification, though vaginal hyperplasia is more frequently an ovary-dependent phenomenon.