Abstract

Using different analytical methods, it was possible to confirm the observation of Ritter [Mol. Pharmacol. 2, 125 (1966)] that within the first few hours after injection of free testosterone into castrated rats there occurs a large yet transient fall in the total level of ATP in the ventral prostate gland. In contrast to Ritter’s findings, however, only marginal changes in the total levels of NAD and NADH in the prostate occurred over the first few hours after androgen administration. The findings presented do not support Ritter’s conclusion that an increased biosynthesis of NAD represents a major early biochemical event in the action of androgens on the prostate of orchiectomized rats. Observations on the properties of prostatic nuclear nicotinamide mononucleotide adenylyltransferase (EC 2.7.7.1) and changes in the activity of this enzyme due to androgen deprival and administration are documented. An NMN-dependent polymerization of the adenylate moiety of ¹⁴C-ATP by prostatic cell nuclei is also described.