AJP - Renal Physiology, Vol 245, Issue 4 470-F477, Copyright © 1983 by American Physiological Society
Transepithelial voltage changes during prostatic secretion in the dog
E. R. Smith, T. B. Miller and R. F. Pebler
To define the nature of Na+, K+, and Cl- secretion by the dog prostate, the
electrical potential difference between fluid in the prostatic urethra and
venous blood was recorded during secretion provoked in
pentobarbital-anesthetized dogs by electrically stimulating the hypogastric
nerves or by administering pilocarpine intravenously. The resultant
prostatic fluid samples as well as plasma samples taken before and/or after
secretion were analyzed for these electrolytes. During secretion provoked
by either means the transepithelial electrical potential difference, which
was essentially zero at rest, became lumen negative, the maximum change
(which was related to gland size) being about 4 mV. The time courses of
both the potential change and the secretion of fluid were very similar. The
Na+ concentration in both nerve- and pilocarpine-induced prostatic fluid
was equal to that in plasma, whereas the K+ and Cl- concentrations were
higher than in plasma. It is concluded that Na+ may move passively from
plasma into prostatic fluid, perhaps via the paracellular route, but the
movement of K+ and Cl- probably involves active transcellular transport.
