FUNCTIONAL INDICATORS OF THE RAT SMALL INTESTINE DURING IMITATION OF CHRONIC STRESS BY INTRODUCTION OF HIGH DOSES OF CORTICOSTERONE
Glucose absorption in the small intestine, the content of glucose transporters SGLT1, GLUT2, and activities of the key intestinal carbohydrases were investigated during daily injections to rats for three weeks of corticosterone at doses corresponding to moderate and severe stress (4 and 12 mg/kg). The injection of the hormone caused a dose-dependent increase in glucose absorption in the small intestine, which was estimated from the rate of consumption by the starved rats of 20% glucose solution. This effect was accompanied by an increase in the content of GLUT2 transporter (but not SGLT1) in the apical membrane of enterocytes, detected by immunohistochemistry. The activities of glucoamylase and maltase were elevated at a dose of 12 mg/kg of the hormone. Thus, at high concentrations of corticosterone in the blood, that simulated chronic stress, an increase in glucose absorption, the content of GLUT2, and the activities of carbohyd- rases in the small intestine may contribute to the hyperglycemia under these conditions