The gastrointestinal tract in hypokinetic rats.

In Wistar rats kept for 15, 30 and 60 days in a hypokinetic state in special cages, alteration of some gastrointestinal glands was studied by means of histochemical and electron microscopic methods. After 15-30 days of hypokinesia, a decrease was found in the muco-polysaccharide content of the submaxillary, gastric and duodenal glands. The intestinal goblet cells appeared vacuolated. The oxyntic cells, which secrete HCl, as well as the G antral cells, which secrete gastrin, were in an active state. The hypokinetic rats exhibited increased gastric secretion. The electron microscopic aspect of the principal cells corresponded to augmented pepsin secretion. The enterocytes showed an increase in their leucine aminopeptidase, acid phosphatase and glucose-6-phosphatase content. In the submucosa of the fundus of the stomach an accumulation of eosinophils was observed. These modifications were more striking after 15 than after 30 days, and disappeared after 60 days of hypokinesia. These morphological and functional changes may be explained by glucocorticoid hypersecretion corresponding to a stress reaction.