Supranormal nuclear content of 5 alpha-dihydrotestosterone in benign hyperplastic prostate of humans.

We investigated the concentration of nuclear and cytosolic 5 alpha-dihydrotestosterone and 3 alpha-androstanediol in benign prostatic hyperplasia (BPH) in men. The endogenous content of the androgens was quantitated by radioimmunoassay after isolation of the nuclear and cytosolic fractions by classical differential centrifugation techniques. The mean dihydrotestosterone content was about four-fold higher (P < .01) than normal in the nuclear fraction and two-fold higher (P = .05) in the cytosolic fraction in periurethral tissue from hyperplastic prostates. The mean 3 alpha-androstanediol values were approximately one-third of normal in both the nuclear (P < .01) and cytosolic (P < .01) fractions in glands with BPH. In BPH tissue the ratios of dihydrotestosterone to androstanediol content in both the nuclear and cytosolic fractions was significantly higher (P < .01) than the ratio in normal prostate. Our data suggest that elevated intranuclear dihydrotestosterone but not 3 alpha-androstanediol may be causally related to the development of BPH in aging men.