Effect of a nonsteroidal antiandrogen, flutamide on intraluminal acidification in rat testis and epididymis.

Flutamide, a pure antiandrogen was administered to intact adult male rats to study the effect of altered availability of hormones on in situ pH, PCO2 and bicarbonate concentration ([HCO3-]) of seminiferous tubules, proximal caput, middle caput, middle corpus, and proximal cauda epididymidis. The weights of the epididymis and ventral prostate as well as the plasma testosterone level showed antiandrogenic effects of flutamide. Relative to controls, flutamide elevated significantly in situ pH in proximal caput, middle caput, middle corpus and proximal cauda epididymidis but not in seminiferous tubules. In situ PCO2 values in the above segments, after flutamide, were indistinguishable from controls and from each other but all values remained significantly higher than systemic arterial blood PCO2. Flutamide treatment did not change the [HCO3-] in systemic arterial blood or seminiferous tubules but increased markedly the values in proximal caput and middle caput. The results of the present studies support the view that luminal acidification in the rat epididymis is under androgen control and may be important for sperm maturation and storage.