A study of the androgenic function of the epididymis

Rats were subjected to bilateral orchidectomy or orchido - epididymidectomy and maintained on either 500 micrograms testosterone or testosterone propionate daily. The ventral lobes of the prostate were subsequently excised and examined for androgen receptors in terms of the total present in the cytosol and the nucleus, the proportion unoccupied by endogenous androgen and the relative populations that were nuclease excisable or nuclease resistant in the two groups of animals. A further group of animals was subjected to unilateral deferential venotomy and the same parameters examined in the ipsi- and contra-lateral lobes of the ventral prostate and the seminal vesicles. In the absence of the epididymides there was a reduction in the number of receptors per prostatic cell and an increase in the proportion that were unoccupied. The nuclei from these glands contained fewer receptors than did those from the animals in which the epididymides had not been excised. The effect of unilateral deferential venotomy was to bring about a relative increase in the number of cytoplasmic receptors in the ipsilateral lobes of the ventral prostate with a much greater proportion unoccupied compared with the lobes contra-lateral to the ligation. There was again an increase in the proportion of nuclease-sensitive receptors in the nuclei ipsilaterally. The conclusions are that the absence of the epididymides in androgen-maintained rats or deferential venotomy induces a relative androgen- deficiency of the prostate and seminal vesicles as reflected in the androgen receptor populations of these organs.