In several experimental models, lipopolysaccharide (LPS) plays an important role in the pathogenesis of liver diseases. Murine models of C3H/HeN and C3H/HeJ mice have been used to elucidate the role of LPS and its responsive-macrophages in vivo, as C3H/HeN strain mice are known to be LPS-responsive, while C3H/HeJ strain mice are LPS-resistant. Furthermore, release of several kinds of biologically active mediators such as interleukin-1, tumour necrosis factor-alpha, colony stimulating factor and reactive oxygen radical is not enhanced in C3H/HeJ mice even after stimulation with LPS. Thus, these murine models could be suitable for clarification of endotoxin induced cellular communication in the liver.