EFFECT OF ADRENALINE ON GLUCOSE UPTAKE BY THE CANINE LARGE BOWEL

The effect of adrenaline on the glucose uptake by the large intestine was studied on a fasted, anaesthetized dog. A vein draining a segment of the colon was cannulated for blood flow measurement and blood samples were obtained for measurement of glucose content of the arterial and venous blood from the colonic segment. Glucose uptake was calculated as the product of colonic blood flow and arterio-venous glucose difference {(A-V) glucose}. When adrenaline (5μg/kg) was injected, glucose uptake by the colon increased by about 150%. This increase is much less than increases of 400% and 700% observed in upper jejunium and terminal ileum respectively in previous studies. However, the resting glucose uptake of (28.28 ± 20mg/min) of the colon is higher than that of the small intestine (17.77 ± 1.56 mg/min). We suggest from our studies that lower glucose uptake in the colon may well indicate a lower metabolic activity in the colon. From the results we concluded that the colon is involved in glucose homeostasis and that the colonic increase in glucose uptake in response to adrenaline is mediated by alpha and beta adrenergic receptors.