Sulpiride or Dogmatil (Delagrange, Paris) was injected to male rats at the rate of 40 mg/day for either 10 or 20 days. Ponderal fluctuations of the accessory organs followed by a quantitative analysis of fructose and of serum acid phosphatases issued from testis epididymis and prostates (PAP) were studied. The coagulating glands alone reacted strongly and their initial weight doubled in 20 days. On the contrary, the fructose decreased sharply in all accessory glands especially in the coagulating glands. The PAP decreased slightly. The fact the concentration of serum PAP remained relatively high even in the castrated males, can be explained by the increase in the lysosomial activity due to retention and diminution of secretion granules. Fructose and PAP are conditioned by androgens and their quantitative decrease suggests that the testosterone level decreased. Hyperprolactinemia induced by Sulpiride is concomittent to testosterone diminution and the effect of each hormone cannot easily be separated. In the castrated animals the effects of Sulpiride were minimized due to the difficulty in observing significant variations between treated and untreated castrates.