Androgen levels in the lipid of the canine vas deferens and peripheral plasma.

Radioimmunoassays were used for the measurement of several androgens in canine plasma and in the liquid of the vas deferens. Large variations in the plasma concentrations of androstenedione, testosterone and 5 alpha-dihydrotestosterone occurred during a period of 24 h, but there was no evidence of a circadian rhythm. The ratios of the androgen concentration in the liquid of the vas deferens compared with that in the peripheral plasma were: androstenedione, 4.6; testosterone, 1.9; 5 alpha-dihydrotestosterone, 13.6; 5 alpha-androstane-3 alpha, 17 beta-diol, 17.0; 5 alpha-diol, 22.4. These high levels of androgens in the liquid of the vas deferens could play a role in the development of prostatic hypertrophy.