THE DISTRIBUTION OF RADIOACTIVITY IN NONEXCRETORY ORGANS OF THE MALE RAT AFTER INJECTION OF TESTOSTERONE-4-C14123

Abstract

After the subcutaneous injection of physiologic amounts (about 0.1 mg.) of testosterone-4-C¹⁴ of high specific activity, significant concentrations of radioactivity were found in several non-excretory tissues of pubescent rats. The concentrations of radioactivity localized in ventral prostates and other accessory sex glands averaged about two and a half times as great as that in muscle. The average prostatic concentration of radioactivity in recently castrated animals was not significantly different from that detected in intact pubescent rats, but the levels were more variable from animal to animal in the castrates. The localization of radioactivity after testosterone-4-C¹⁴ administration was not influenced by the presence of biliary fistulae. It is suggested that the radioactivity detected in the tissues probably represented androgen or a derivative.