LPS-INDUCED ANOREXIA IN LEPTIN-DEFICIENT (OB OB) AND LEPTIN RECEPTOR-DEFICIENT (DB/DB) MICE/

Administration of endotoxin (lipopolysaccharide, LPS) induces profound anorexia. Injection of leptin decreases food intake in mice. Recently , we reported that LPS and cytokines increase leptin levels in hamster s. To further investigate the role of leptin in the LPS-induced anorex ia, we administered LPS to leptin receptor-deficient (db/db) and lepti n-deficient (ob/ob) mice. We found that LPS caused anorexia in both db /db and ob/ob mice. As might be predicted if leptin had a role in anor exia, the db/db mice were somewhat resistant to LPS-induced anorexia. However the ob/ob mice were more sensitive to LPS-induced anorexia. No differences between db/db and ob/ob mice and their respective litterm ate were observed in circulating tumor necrosis factor levels after LP S. These data suggest that leptin per se is not essential for LPS-indu ced anorexia.