Cholecystokinin receptors do not mediate the behavioral effects of lipopolysaccharide in mice

To test the possible role of cholecystokinin (CCK) in the decrease of social exploration induced by intraperitoneal (IP) injection of lipopolysaccharide (LPS, 100 mu g/kg), mice were pretreated with IP or intracerebroventricular (ICV) injection of the CCKA receptor antagonist L-364,718 (3 mg/kg and 10 mu g/kg, respectively) and the CCKB receptor antagonist L-365,260 (1 mg/kg and 10 mu g/kg, respectively). L-364,718 and L-365,260 did not alter LPS-induced decrease in social investigation, whatever the route of administration, suggesting that endogenous cholecystokinin does not mediate the effect of proinflammatory cytokines on social exploration in mice. (C) 1997 Elsevier Science Inc.