Influence of intragastric pH on electrolyte secretion by the guinea-pig stomach.

1. A technique is described for the continuous assessment of acid secretion by the guinea-pig gastric mucosa at selected levels of intragastric pH.2. The rate of hydrogen ion secretion increases linearly with pH over the intragastric range of pH 4.4 to 9.4. Sodium and potassium secretions are not clearly related to pH. Outputs of both chloride and bicarbonate rise as pH is increased.3. The carbonic anhydrase inhibitor acetazolamide reversibly reduces rapid rates of acid secretion as occur when gastric contents are maintained at pH 10.4. Alkali stimulated acid output is not inhibited by atropine (2 mg/kg) and probably results directly from increased carbonic anhydrase activity as the in vitro activity of the enzyme may be correlated with the rate of acid secretion over a wide range of pH.