Hyperinsulinemia and obesity in the dorsolateral tegmental rat

Adult female rats (N = 26) were prepared with either sham lesions or electrolytic lesions of the dorsolateral tegmentum (DLT). Body weight gain, adiposity, 72-hour food intake and day/night food intake, serum glucose and serum insulin levels were measured 15 and 17 days post-operatively. Dorsolateral tegmental lesions produced moderate weight gains and enhanced adiposity as assessed by the Lee Index. Although dorsolateral tegmental rats were hyperphagic only at night, hyperinsulinemia was observed during the day and the night. Hyperinsulinemia may contribute to the obesifying action of tegmental lesions in rats fed high-fat diets.