SCANNING ELECTRON MICROSCOPIC OBSERVATION OF THE GASTRIC MUCOSA OF RATS GIVEN WATER IMMERSION STRESSES

Abstract

Rats were immersed in water, and possible changes in the fine structure of the gastric mucosa resulting from immersion stresses, which may appear before the development of macroscopic lesions, were followed up with time under a scanning electron microscope. In an early stage of immersion, the hypersecretion of mucous granules from surface epithelial cells was recognized. It was followed by the flattening of these epithelial cells, then by the enlargement of gastric pits. As the duration of immersion was extended, the epithelial cells became globose and, eventually, they dropped out. And finally surface epithelium disappeared. This disappearance of surface epithelium was considered to represent gastric mucosal lesions observable macroscopically. The changes of the gastric mucosa resulting from water immersion stresses were noticed earlier in the gastric body than in the pylorus. These results suggest that though surface epithelial cells of rat stomach actprotectively against stressor in the early stress stage, subsequent exhaustion of protective potential of the cell by prolongation of the stress period results in mucosal injury.