CHRONIC EFFECTS OF GLUCAGON ON FOOD INTAKE AND BODY WEIGHT OF NORMAL, DIABETIC AND VENTROMEDIAL HYPOTHALAMUS LESIONED RATS

Resumen

It has been reported that large doses of glucagon produce reductions in caloric intake and body weight. In the present paper, the effects of small doses of glucagon on daily food intake and body weight of normal, diabetic, or VMHx obese rats were studied. Glucagon (15 μ.g/ kg) was subcutaneously injected twice daily nine days in 8 normal, 13 alloxandiabetic and 5 VMHx rats. As compared with the values obtained during a previous and a posterior period of nine days each, glucagon produced in normal rats mild but significant increases in food intake, body weight and energetic balance (change in body weight/ total ingested food). The same values significantly decreased in diabetic rats. In VMHx rats only food intake decreased significantly but in a gradual way, the slope being negative during glucagon administration and positive during the two control periods. The results confirm that glucagon produces a negative energetic balance and reduction in food intake; at low doses these effects could be masked by its insulinogenic action. Besides, it is suggested that VMH
receptors monitor pancreatic hormone concentration which could thus centrally influence feeding behavior.