THE INHIBITION OF HAIR GROWTH BY ESTROGENS AS RELATED TO ADRENAL CORTICAL FUNCTION IN THE MALE RAT1

Abstract

Male rats of the Sprague-Dawley strain were force fed a medium carbohydrate diet during a study of the effect of large doses of estrogen (20-40 [mu]g. day) on hair growth. The following exptl. conditions were represented: sham adrenalectomy, no estrogen; sham adrenalectomy, estrogen; adrenalectomy, no adrenal cortex extract (ACE) and no estrogen; adrenalectomy, no ACE, estrogen; adrenalectomy treated with ACE (5-10 ml. day), no estrogen; and adrenalectomy treated with ACE, estrogen. Two rats were studied under each of these conditions in each of 4 separate expts. Estrogen inhibited hair growth in non-adrenalectomized rats and in adrenalectomized rats treated with ACE but failed to sustain inhibition of hair growth in adrenally insufficient rats. In a 5th expt., 12 adrenalectomized rats were treated with ACE for a period of 9 wks. Six of the rats received estrogen and 6 did not. Estrogen almost completely inhibited hair growth whereas hair continued to grow in the ACE-treated rats without estrogen. Microscopic observations of the skin showed that estrogen suppressed the activity of the hair follicle in non-adrenalectomized rats and in adrenalectomized rats treated with ACE but did not have this effect in the adrenally insufficient rats.