INTERLEUKIN-1-BETA-CONVERTING ENZYME-DEFICIENT MICE RESIST CENTRAL BUT NOT SYSTEMIC ENDOTOXIN-INDUCED ANOREXIA

Interleukin-1 beta (IL-1 beta) mediates many of the behavioral respons es to infection and inflammation, and IL-1 beta-converting enzyme (ICE ) processes intracellular IL-1 beta, leading to its maturation and sec retion. Here we demonstrate that intracerebroventricular injections of lipopolysaccharide (LPS) produced a greater reduction in both food in take and food-motivated behavior in wild-type compared with ICE-defici ent (ICE -/-) mice. This defect occurred although ICE -/- mice were ab le to fully respond to intracerebroventricular injections of IL-1 beta . In contrast, ICE -/- mice remained fully responsive to intraperitone al injections of LPS. These results indicate that brain, but not perip heral, IL-1 beta plays a critical role in the depression in food intak e that occurs during inflammation.