GLUCOSE-TOLERANCE AND SERUM-INSULIN LEVELS IN AN ANIMAL-MODEL OF OBESITY-INDUCED BY THE ANTIPSYCHOTIC DRUG, SULPIRIDE

To assess the role of insulin in the development of obesity induced by antipsychotic drugs, a glucose tolerance test was conducted in 40 fem ale rats during the peak of sulpiride-induced weight gain and in 40 ve hicle-treated animals. The glucose area under the curve did not differ between the groups (P=0.24), however, the area under the insulin curv e was significantly decreased by sulpiride (55.2+/-2.8 versus 115.6+/- 18.9, P=0.007). The results suggest that insulin resistance and hyperi nsulinaemia are not involved in the excessive weight gain observed in this animal model of drug-induced obesity. Alternatively, the insulin- dampened response observed in the sulpiride-treated rats may be relate d to increased insulin sensitivity, which may promote weight gain as p roposed by Ravussin (1995).