Tissue sources of sex steroids in rat ovaries in the preovulatory period

Abstract

To determine the degree to which the various structures of the ovaries participate in the preovulatory synthesis of sex hormones quantitative histoenzymologic analysis was used. Activity of 3β-, 17β-, and 20α-steroid dehydrogenases, glucose-6-phosphate dehydrogenase, and NAD- and NADP-diaphorases was investigated. Sex hormone synthesis was shown to take place through the combined function of all structures of the gland. In early proestrus increased estrogen synthesis occurs in the follicles, interstitial glands, and old corpora lutea. Young corpora lutea and follicles are active sources of synthesis of progesterone and 20α-hydroxypregn-4-en-3-one (middle proestrus) whereas the old corpora lutea at this time are chiefly synthesizing a progesterone derivative.