Verapamil and indomethacin attenuate endotoxin-induced anorexia

To characterize the mechanism of the anorexia during infection, we investigated the effect of E. coli lipopolysaccharide (LPS) on feeding in rats under various conditions: LPS (125, 100, 75, and 50 micrograms/kg body weight = b. wt.) injected intraperitoneally (IP) reduced food intake by decreasing meal frequency without affecting meal size. The Ca++-channel blocker verapamil (5 mg/kg b. wt., IP) or the antipyretic and antiphlogistic drug indomethacin (2.5 mg/kg b. wt., IP), but not combined alpha- and beta-adrenergic receptor blockade by IP phentolamine plus propranolol (500 micrograms/kg b. wt., each) attenuated the anorectic effect of LPS (125 or 100 micrograms/kg b. wt.). The results suggest that a phospholipase A2-sensitive mechanism contributes to the anorexia during injection.