Prostatic function in the brush-tailed possum, Trichosurus vulpecula

Abstract

Perspex casts were made of the reproductive tract and the blood vessels supplying the prostate of the brush-tailed possum. The urethra is surrounded by a network of arteries and veins from which a large number of small vessels radiate into the body of the prostate. This complex of vessels might be capable of transferring androgens carried from the epididymis to the urethra into the prostatic parenchyma. Testosterone 5.alpha.-reductase was of highest specific activity in the epididymis and was more active in the posterior than the central prostate. The 2 metabolites of testosterone detected were 5.alpha.-dihydrotestosterone and 5.alpha.-androstane-3.alpha.,17.beta.-diol. In 3 untreated possums in Dec. the mean serum concentrations of testosterone, DHT [.alpha.-dihydrotestosterone] and androstenedione were 3.8, 1.9 and 0.4 ng/ml, respectively. Zn concentrations (mean .+-. S.E.M. [standard error of the mean], N = 3) were 1.6 .+-. 0.1 .mu.g/ml serum, 61 .+-. 13 .mu.g/g central prostate and 13 .+-. 2 .mu.g/g posterior prostate. There was a positive correlation between serum testosterone concentration and prostatic weight.