Effects of testosterone, testosterone metabolites and anti-androgens on the function of the male accessory glands in the rabbit and rat.

The androgenic potencies of testosterone, 5alpha-dihydrotestosterone, 5alpha-androstane-3alpha,17beta-diol and 5alpha-androstane-3beta,17beta-diol towards the prostate, glandula seminalis+glandula vesicularis, ampullae and epididymis were evaluated after administration to castrated rabbits. The influence of cyproterone acetate, stilboestrol and medrogestone on accessory gland function was also investigated in rabbits and rats. In the rabbit it was found that the minimum dose of testosterone propionate that would maintain the function of all accessroy glands at normal levels was approximately 200 microgram/animal/day. Higher levels of testosterone propionate overstimulated the function of the prostate, glandula seminalis+glandula vesicularis and ampullae, but did not affect the epidiymis. Whereas testosterone propionate and 5alpha-dihydrotestosterone propionate were essentially equipotent in their capcity to support growth and secretory activity and stimulated all the accessory glands, 5alpha-androstane-3alpha,17beta-diol dipropionate had a pronounced differential effect; it was considerably more potent than testosterone propionate in promoting secretion in the prostate, but was ineffective in maintaining the function of the epididymis. 5alpha-Androstane-3beta,17beta-diol dipropionate was the weakest androgen tested. Evidence also indicated that the potency of a steroid can depend on whether it is administered as its free or esterified form. Cyproterone acetate suppressed fructose secretion in the prostate of the rabbit but had no adverse effects on the function of the epididymis in either the rabbit or rat. Stilboestrol was the most potent anti-androgen tested and medrogestone the least effective.