Effect of restraint on gastric acidity in the rat

Abstract

Chronic gastric fistula rats were prepared by implanting stainless steel cannulas in the rumen portion of the stomachs of male Holtzman rats and gastric content was collected in both the unrestrained and restrained state. Gastric secretion in acute pylorus-ligated rats, unrestrained and restrained, was studied at the same time. Volume of gastric content, free and total acidity, and free acid output were significantly lower in the chronic fistula rats as compared to the pylorus-ligated rats in the initial 4-hr collection period. A study of 24-hr gastric content in chronic fistula rats showed that restraint produced a significant decrease in volume, a significant increase in free and total acid concentration, and no change in free acid output, while the restrained pylorusligated rats had a significant decrease in volume, no change in free or total acid concentration, and a significant decrease in free acid output as compared with control values. This suggests that an increase in acid concentration is an important change produced in gastric secretion by restraint stress.