Morphological studies on the margin of gastric corpus wounds in the rat.

The serosa of gastric corpus in adult rats was briefly exposed to 80% acetic acid, and as a result wounds appeared in the subjacent mucosa. The rats were killed 2, 3, 6, 10, 14 or 21 days later, and the wound margins were prepared for light and electron microscopy. The marginal glands became cystically dilated, and the gastric pits increased in depth. Many of the mucous cells at the surface contained large lipid droplets. The zymogen cells lost most of their secretory granules and the bottom of the glands became dominated by mucous cells. The tubulo-vesicles disappeared from the parietal cells, and the volume density of mitochondria was reduced from 34% to 23%. The secretory canaliculi also became smaller than normal. The morphological changes in the epithelial cells were so marked that the secretory capacity might be impaired. Measurements on the surface of the wound margins showed neutral pH in stimulated rats, indicating that the parietal cells had discontinued their secretion of acid.