Intercellular adhesion molecule-1 expression in experimental alcoholic liver disease: Relationship to endotoxemia and TNFα messenger RNA

We used the intragastric feeding rat model for alcoholic liver disease to evaluate the relationship among intercellular adhesion molecule-1 (ICAM-1) expression, tumor necrosis factor-α (TNF-α), plasma endotoxin, and inflammatory changes in the liver. Rats were fed different dietary fats (salurated fat, corn oil, and fish oil) with ethanol; control rats were fed isocaloric amounts of dextrose instead of ethanol. At sacrifice the following were evaluated: Liver pathologic changes, TNF-α mRNA by reverse transcription-PCR, plasma endotoxin, and ICAM-l by immunohistochemistry and immunoblot analysis. Upregulation of ICAM-1 in endothelial lining cells in central and portal veins was observed in rats showing evidence of pathologic changes. Rats fed fish oil and ethanol, which exhibited the most severe inflammation, also showed hepatocyte ICAM-1 staining. The presence of ICAM-1 staining, in general, correlated with the level of TNF-α mRNA expression and plasma endotoxin levels. Upregulation of ICAM-1 in rats fed ethanol may contribute to the inflammatory changes seen in this model. The association between ICAM-1 upregulation and endotoxin and TNF-α mRNA suggests a role for these mediators in the inflammatory process in alcoholic liver injury.