EFFECTS OF THE OBESE GENE-PRODUCT ON BODY-WEIGHT REGULATION IN OB OB MICE/

C57BL/6J mice with a mutation in the obese (ob) gene are obese, diabet ic, and exhibit reduced activity, metabolism, and body temperature. Da ily intraperitoneal injection of these mice with recombinant OB protei n lowered their body weight, percent body fat, food intake, and serum concentrations of glucose and insulin. In addition, metabolic rate, bo dy temperature, and activity levels were increased by this treatment. None of these parameters was altered beyond the level observed in lean controls, suggesting that the OB protein normalized the metabolic sta tus of the ob/ob mice. Lean animals injected with OB protein maintaine d a smaller weight loss throughout the 28-day study and showed no chan ges in any of the metabolic parameters. These data suggest that the OB protein regulates body weight and fat deposition through effects on m etabolism and appetite.