Pathophysiological Investigations of Peptic Ulcer-Secretory Function and Emptying-

Part I: The effect of antacids on gastric pH

Abstract

The effect of antacids on gastric pH was observed using telemetering pH capsules and phenol red test meal method.
1. The comparative observations in vitro on the pH of the various buffer solutions (pH 2-7) and various foods were done between the Heiderberger's pH capsule and glass electrode. The error within pH 0.5 was occasionally detected in case of buffer solutions, and that ranging pH 0.5-1.0 was seen in case of various foods.
2. The secretory volume and the acid out put measured by means of phenol red test meal (50ml) were proved to be applicable to judge the effect of the drugs and the diet on the gastric functions, although those values were calculated somewhat higher than those with Kay's method.
3. The gastric pH pattern was different from one antacid to another. After oral or intragastric administration of each usual dosis of the various antacids, the antacid effect was seen as long as 40 minutes or less in most cases. Effect of the commercial granules containing Aluminium hydroxide was not so marked, and the duration of the effect was shorter.
4. The alkali time by means of alkalitest (50ml of 1% Na. bicarbonate) could not be appreciated as the index of the secretory function. In vitro observations showed that the alkali time was dependent not only on the acid secretion but on the emptying of the stomach, the influence of the latter being especially marked in cases of the acidity between 10-30 mEq/l.