REGULATION OF ADIPSIN AND BODY-COMPOSITION IN THE MONOSODIUM GLUTAMATE (MSG)-TREATED MOUSE

Changes in food intake, serum adipsin, and obesity were evaluated in t he MSG-treated mouse. In Experiment 1, mice treated with MSG had 50% l ower serum adipsin and over 2-fold higher percentage of body fat than the lean controls. Both feeding caffeine and restricting intake normal ized serum adipsin and caused weight loss, but did not normalize the p ercentage of body fat. No additional effect was gained by feeding isop roterenol or ephedrine in combination with caffeine. In Experiment 2, we separated the direct effect of caffeine from the associated depress ion in intake using a paired feeding design, and also determined the e ffects of selected adrenergic agents and somatotropin (S). Somatotropi n increased weight gain and reduced the percentage of body fat in heal thy and obese mice, and tended to lower serum adipsin. Caffeine clearl y depressed intake, caused weight loss, and increased serum adipsin, b ut similar results were achieved by restricting intake. None of the ad renergic drugs tested changed serum adipsin. Ephedrine depressed food intake and caused weight loss, but reduced the percentage of body fat only at the highest dietary concentration (2000 mg per kg of diet). Ph enylephrine reduced weight gain without a concomitant effect on the pe rcentage of body fat, and isoproterenol did not influence weight gain or body fat. Copyright (C) 1996 Elsevier Science Inc.