Intracellular localisation of 5alpha-dihydrotestosterone in human benign prostatic hypertrophy.

When slices of benign hypertrophied human prostate and abdominal muscle were incubated with either [3H]testosterone or 5alpha-dihydro[3H]testosterone, the uptake of radioactivity by prostatic tissue was significantly higher than that of the muscle (P less than 0.01). The uptake of labelled androgen by prostatic tissue could be significantly reduced by adding the unlabelled steroid to the incubation medium. After the incubation of prostatic tissue with 5alpha-dihydro[3H]testosterone, the amount of the radioactivity taken up by the whole homogenate and the nuclear preparation of the prostatic tissue were measured. DNA content of the nuclei and the whole homogenate was also estimated. The mean+/-S.E.M. of 5alpha-dihydrotestosterone associated with the nuclei was 65+/-4.4%, ranging from (52.2-79.8%). The activity of acid phosphatase was measured in 30 samples of prostatic tissue. The mean +/- S.E.M. was 20.7+/-1.5 U/g tissue (9.8+/-0.9 U/mg DNA). The correlation between the activity of this enzyme and the uptake of androgen by prostatic tissue is evaluated.