Feeding an isocaloric omega-3 fatty acid diet reduces the brush border membrane vesicle uptake of glucose in streptozotocin-diabetic rats.

Abstract

Glucose uptake is increased into the intestine of diabetic rats, and this adaptation can be modified further by manipulation of the type of fatty acids in the triglycerides in the diet. Jejunal brush border membrane vesicles were used to examine the uptake of D-glucose into the jejunum of non-diabetic control and streptozotocin-diabetic rats fed for two weeks in isocaloric semisynthetic diet enriched with saturated fat (beef tallow) or polyunsaturated omega-3 fatty acids (fish oil). The time-course of uptake of 100 microM glucose demonstrated an overshoot which peaked at approximately 30 seconds and declined thereafter to an equilibrium plateau. In concentration studies, glucose uptake was greater into brush border membrane vesicles of diabetic as compared with control rats. The maximal transport rate (Vmax) was increased approximately 9-fold in diabetics as compared with control rats fed beef tallow (p < 0.05), and was increased approximately 6-fold in diabetic rats fed fish oil. In diabetic rats, feeding fish oil reduced the value of the Vmax by approximately 50% as compared with diabetic rats fed beef tallow. Thus, the enhanced glucose uptake into BBM vesicles of streptozotocin-diabetic rats can be partially corrected by feeding an isocaloric semisynthetic diet enriched with polyunsaturated omega-3 fish oils.