Preliminary observations on steroid metabolism in isolated epithelum of guinea pig seminal vesicle.

The metabolism of nine radioactively labeled steroids in the epithelium of the seminal vesicle of the mature guinea pig has been studied. The rapid assimilation and metabolism of these steroids demostrate the very active biochemical nature of this tissue. Based on the use of several thin-layer chromatography systems and comparison with the locations of known standards, the following have been disclosed. Testosterone was rapidly converted to dihydrostestosterone and androstanediol. The latter was the major metablolite of dihydrotestosterone and of androsterone. Androstenedione was readily converted to androstanedione, testosterone, and dihydrostestosterone, although it formed little androstanediol. Dehydroepiandrosterone was converted to small amounts of androstenediol and androstanediol. Pregnenolone was rapidly converted to an unidentified highly polar compound only. Progesterone was converted to 5alpha-pregnane-3beta-ol-20-one and its 3alpha-isomer. Dehydroepiandrosterone and progesterone were also significantly converted to unidentified highly polar compounds. The major metabolites of 17-hydroxyprogesterone co-chromatographed with standard androstanediol, testosterone, and unidentified metabolite possessing intermediate chromatographic mobility. In addition, 17-hydroxyprogesterone was converted to small amounts of compounds possessing identical Rf values as standard androstenedione and dihydrostestosterone. The identification of the products of 17-hydroxyprogesterone metabolism and their physiologic significance must await critical evaluation. Because of its homogeneity, isolated epithelium of guinea pig seminal vesicle shows promise as a tissue preparation for use in future studies that might elucidate the role(s) of individual androgens in secretory tissues of the male accessory sex organs. Our demonstration of extensive steroid interconversions in this tissue is a logical prerequisite to such studies.