(De)phosphorylation agents influence 5 alpha-reduction of testosterone in human prostate.

The effects of ATP and of 2,4-dinitrophenol (DNP) on the kinetics of 5 alpha-reductase were studied in a microsomal preparation from hyperplastic human prostates. DNP decreased and ATP increased enzyme activity in a dose-dependent manner. Furthermore, in one and the same prostate, activity was inversely correlated to prostatic acid phosphatase (PAP) concentration. These observations provide strong support for the contention that in the human prostate 5 alpha-reductase activity and, consequently, dihydrotestosterone (DHT) production may be energy dependent and involve a phosphorylation step.