The endogenous concentration and subcellular distribution of androgens in normal human premenopausal endometrium, myometrium and vagina

Abstract

The endogenous concentrations of testosterone (Testo), androstenedione (Adion), 5-androstene-3β3,17β-diol (Adiol), dehydroepiandrosterone (DHEA) and DHEA-sulfate (DHEAS) have been measured in endometrium, myometrium and vagina from 23 premenopausal women at different stages of the cycle. The tissue to plasma gradient was positive for all androgens except DHEAS; a significant correlation existed between plasma and tissue levels of Adiol and DHEAS. In all tissues significant correlations were calculated between Adiol and DHEA, Adion and Testo, and Adiol and DHEAS. Except for Testo, androgen concentrations were different in the tissues with a significant correlation between the tissues, each tissue seeming to be able to create its own specific intratissue androgen pattern. During the cycle Testo was highest in myometrium and vagina and Adion in myometrium and endometrium during the secretory phase. Except for DHEA, androgens were preferentially localized in the cytosol fraction of the cells. From this localization and the known inhibitory effects of androgens on the activity of estrogen metabolizing enzymes, it is postulated that androgens play a role in enzymatic rather than receptor-mediated processes in uterine cells.