Gastric acid plays a primary role in digestion as well as in the sterilization of food and water. Gastric juice contains the most concentrated physiological acid solution (pH 1) as a result + - of H and Cl ion secretion hydrochloric acid (HCl) production] by parietal cells in the oxyntic mucosa of the stomach. The combined output of the parietal cells leads to the sec- tion of 1-2 l of HCl at a concentration of 150-160 mmol/l into the interior of the stomach. In order to facilitate the production of acid, the parietal cell relies on the generation of a high + concentration of H ions that are...