The Estrogen-sensitivity of the Vaginal Epithelia in Hypothyrosis

Abstract

During our earlier investigations we have observed changes in the estrogen metabolism as a result of hypothyrosis. The genital cycles are lengthened and the sensitivity of the organism towards exogenous estrogens is reduced. We performed experiments to determine whether a reduction of sensitivity to follicle hormone in the target organ, that is, in the vaginal epithelia, is produced by thyroidectomy.
For experimental purposes we have used partly animals with intact endo-crine system and partly those which had been thyroidectomized and ovar-iectomized at the same time. We have performed hormonal treatments intra-vaginally with 4 I. U. of estrous. This dosage given intramuscularly did not produce estrus in hypothyrotic animals. On the other hand, when administered locally, it effected the cornification of the vaginal epithelia. The raising of the dosage lengthened the duration of the reaction.
Our experiments show that estrogen administered locally produces estrus in hypothyrotic animals. This reaction is effected even with the dosages which are ineffective intramuscularly. By raising the doses the time necessary to produce estrus diminishes, whereas its duration is lengthened. This phenomenon is common in the hypothyrotic as well as in the control animals. The changes of estrogen metabolism in hypothyrosis do not affect the sensitivity of the vaginal epithelia to estrogen.