THE VAGINAL SMEAR OF SENILE LABORATORY RATS

Abstract

SUMMARY Rats aged 17 months or more did not undergo regular oestrous cycles during a period of 12 weeks when daily vaginal smears were taken. Vaginal cornification occurred at irregular intervals in most of the animals. Its incidence decreased following unilateral ovariectomy and temporarily increased following injections of gonadotrophin. Acceptance of the male was rare and spasmodic and could not be correlated consistently with the presence of cornified cells in the vaginal smears. Compensatory ovarian hypertrophy after unilateral ovariectomy occurred in all senile animals examined. The response of the vaginal epithelium to oestrogen did not appear to be less in senile than in young animals.