Responses of the Adult Rat Glucose Metabolism to Early Life Feeding, Caloric Restriction and Refeeding

Early life overfeeding in the rat can be experimentally induced by reducing litter size. This investigation assessed the consequences of this manipulation on glucose metabolism in vivo and in isolated hepatocytes in 150-day old rats. Additionally, after body growth, the effects of caloric restriction and refeeding were tested. Adult rats from control (G9) and reduced litters (G3L) did not differ in body and fat weights, glucose tolerance or insulin resistance (insulin-induced hypoglycemia), or hepatocyte glucose release under basal or gluconeogenic conditions. Caloric restriction (G3R) reduced body and fat weights, decreased glucose decay after insulin injection and decreased hepatocyte gluconeogenic glucose release. Refeeding after caloric restriction reversed these parameters to those of the freely-fed groups (G9 and G3L). Taken together, these results suggest that the liver glucose metabolism is not programmed by lactational overfeeding, but rather is responsive to the current nutritional condition of the animal.