Antacids and hormones.

Antacids are neutralizing compounds which have been shown to hasten ulcer healing and to prevent bleeding from stress ulcerations. Owing to gastric alkalinization, gastrin will be released following antacid ingestion, a condition similar to that following the ingestion of a meal. Gastrin release and, more important, acid rebound also occur when the gastric mucosa comes into contact with calcium chloride. These findings indicate that acid rebound is independent of antral neutralization. Acid rebound and gastrin release will also be induced in duodenal ulcer patients by magnesium hydroxide. The magnitude of acid rebound represents one fourth to one third of the peak acid response to pentagastrin and is more marked following calcium than magnesium antacid intake. The mechanism of acid rebound may be in part due to gastrin release, but may also be due to the direct effect of calcium on the parietal cell. In the duodenum, calcium and magnesium evoke pancreatic enzyme secretion and gall bladder emptying. This effect of both cations is attributed to the release of cholecystokinin. Owing to their chemical composition, antacids stimulate the release of gastrointestinal hormones, cause acid secretion and stimulate pancreatic enzyme secretion and gall bladder concentration. So far, it has not been proven that these effects of antacids and of their chemical constituents will limit their therapeutic use.