Digestive and resorptive function of the small intestine in stressful situation

The present study examines the effects of severe stress on digestive and resorptive functions of the small intestine. Transverse 20-minute acceleration (+10 Gx) results in an increase of invertase activity, particularly in distal parts of the small intestine. Although the activity of glycyl-l-leucine dipeptidase was changed, the fluctuations were less pronounced than those in invertase activity. Acceleration also produces rise in glucose accumulated in the intestinal mucosa and intensification of active carbohydrate transport. The displacement of the proximodistal gradient of invertase activity and carbohydrate resorption was significant. Dipeptidase and invertase activities in intestinal sacs and in tissue homogenates were depressed following exposure to 15-, 30- and 60-day hypokinetics. In distal parts the invertase activity was increased, and the resorptive function was enhanced. Following exposure to unusual gaseous atmospheres (hypoxic, hypercapnic and hyperoxic) there was an increase in active glucose transport over the entire length of the small intestine. Heat produces a decrease in invertase activity both in intact cells and homogenates. There were no pronounced changes in dipeptidase activity. Transport processes exhibited some variations.