The effect of acetzolamide on Ion transport across isolated sheep rumen epithelium.

1. The net fluxes of sodium and chloride from the lumen to the blood side of isolated sheep rumen epithelium were reduced by treatment of both sides of the epithelium with acetazolamide. 2. The changes in the net fluxes of sodium and chloride were significantly correlated and showed recovery after removal of acetazolamide. 3. The net flux of potassium from blood to lumen side of the epithelim was not affected by treatment with acetazolamide. 4. It is suggested that acetazolamide blocks coupled sodium and chloride transport which may be mediated through 'low-activity' carbonic anhydrase enzymes.