Résumé : BACKGROUND & AIMS: Interleukin (IL)-10 is a potent anti-inflammatory cytokine. Its role in modulating liver injury induced by galactosamine and lipopolysaccharide (Gal/LPS) was investigated. METHODS: The effects of recombinant IL-10 (rIL-10), anti-IL-10 monoclonal antibodies, or gadolinium chloride (GdCl3) pretreatment were studied in mice challenged with Gal/LPS. Tumor necrosis factor (TNF) alpha and IL-10 serum concentrations were measured and liver injury was assessed by alanine aminotransferase (ALT) serum concentrations and by histology. RESULTS: (1) IL-10 is produced early and together with TNF-alpha after Gal/LPS challenge. (2) Anti-IL-10 pretreatment increases TNF-alpha (+443%, P = 0.04), ALT (+160%, P = 0.04) serum levels, and the percentage of severe necrosis compared with control monoclonal antibodies. (3) Administration of rIL-10 30 minutes before Gal/LPS decreases TNF-alpha (-67%, P = 0.02), ALT (-94%, P = 0.01) serum concentrations, and the proportion of severe necrosis. The hepatoprotective effect is still observed when rIL-10 is injected 30 or 120 minutes after Gal/LPS. (4) GdCl3 pretreatment protects against hepatotoxicity, decreases TNF-alpha, but increases IL-10 serum concentrations. CONCLUSIONS: These results indicate that IL-10 protects the liver in the Gal/LPS mouse model. Increased IL-10 and decreased TNF-alpha secretion are potentially involved in the hepatoprotection observed after GdCl3 pretreatment.