Perfusion of the Boar Testis with Androstenediol Sulfate in vivo and Studies on the in vitro Metabolism of Androgens by Porcine Blood Cells

Abstract

An attempt was made to see if androstenediol sulfate, a normal secretory product of the boar testis, is important in testicular steroidogenesis in this species when perfused in vivo through the testis. Approximately 5 μCi of 7α-3H-androstenediol sulfate were administered via the spermatic artery to four, mature, anesthetized boars. Almost all of the radioactivity extracted from the spermatic vein blood and from the testis was associated with the unaltered substrate. Less than 0.2% of the substrate was isolated as 3H-dehydroepiandrosterone sulfate from the testicular extracts of one boar. An unsuccessful effort was made to characterize a similar amount of a metabolite present in extracts from spermatic vein blood of the same animal. The total amount of radioactivity which was associated with the free steroids represented about 0.2% of the administered dose of 3H-androstenediol sulfate given to each boar.17β-Hydroxysteroid dehydrogenase activity was demonstrated in a series of incubations of steroids with blood cells of the boar. Unconjugated Δ5-steroids were converted to a greater extent than were the Δ4-steroids (3.33 and 3.91% for DHA and androstenediol, respectively; 1.23 and 0.92% for androstenedione and testosterone, respectively). Androstenediol sulfate was converted to dehydroepiandrosterone sulfate (0.42%) but the reverse reaction was not observed. These findings were considered in relation to the in vivo studies. It was concluded that androstenediol sulfate in arterial blood entering the boar testis was not metabolized appreciably.