The pH of prostatic fluid: a reappraisal and therapeutic implications

A basic assumption in all experiments on prostatic physiology, particularly those designed to study the diffusion of drugs into the prostate gland, is that the pH of human prostatic fluid is similar to that of the dog, that is pH 6.1 to 6.5. We believe that this assumption is incorrect. Our data indicate 1) the expressed prostatic secretion of most normal men is alkaline (mean pH 7.31), 2) with prostatic infection the pH of prostatic fluid increases markedly (mean pH 8.34) and, therefore, drugs shown to diffuse into the canine prostate may be ineffective in treating prostatitis in humans and 3) the increase in pH of the expressed prostatic secretion seen with infection is not simply owing to an increase in the relative concentration of alkaline seminal vesicular components. Biochemical markers of seminal vesicular activity (fructose and prostaglandins) showed no correlation with pH values of expressed prostatic secretion. Hence, it appears that the change in pH of the expressed secretion is owing to a real increase in pH of prostatic fluid. The clinical implications of these findings are discussed. An appreciation of the profound variation in the prostatic fluid pH may be of importance not only in furthering the understanding and treatment of chronic bacterial prostatitis but, also, of other prostatic diseases as well.