Abstract
The increase in weight of the rat ventral prostate after testosterone administration to castrated rats was shown to be accompanied with concomitant elevations of both the rate of testosterone 5α-reduction and that of the incorporation of choline-3H into phospholipids in the glands. Time course study revealed that the increase in rate of 5α-reduction and of choline-3H incorporation became evident by 24 hrs after testosterone administration. The increase in rate of 5α-reduction and of choline-3H incorporation into phospholipids was observed in both microsomal and crude nuclear fractions from castrated rats 24 hrs after testosterone administration. The rate of 5α-reduction and DNA content exhibited the similar recovery after the purification of nuclei, however the radioactivity of choline-3H in the crude prostatic nuclei was lost during the procedure for purification of the nuclei. Therefore, it was concluded that the increase in rate of 5areduction and choline-3H incorporation into phospholipids took place simultaneously after the administration of testosterone, however sites of increased testosterone 5α-reductase did not seem to be located on the newly synthetized membranes.
5α-Androst-l-ene-17β-ol-3-one, known to be a potent androgen, evoked a similar increase in DNA content, the rate of 5α-reduction and DNA polymerase activity after testosterone administration to ventral prostate of castrated rats. This suggested that the increase in testosterone 5α-reduction observed did not seem to be a substrate-induced change.
