Rat hepatocytes and Kupffer cells interact to produce interleukin-8 (CINC) in the setting of ethanol.

Interleukin-8 is a neutrophil chemoattractant that has been implicated in the pathogenesis of alcoholic hepatitis. The mechanism of ethanol-induced interleukin-8 production in liver is uncertain, although hepatocytes and Kupffer cells have both been proposed as sources of the chemokine. In this study we investigated whether short-term ethanol exposure stimulates production of rat interleukin-8 [cytokine-induced neutrophil chemoattractant (CINC)] by normal rat hepatocytes and Kupffer cells in primary culture. Initial experiments verified that hepatocytes and Kupffer cells produce CINC in response to cytokines or lipopolysaccharide. Ethanol, by contrast, failed to stimulate CINC secretion by either cell type even at concentrations as high as 100 mM. Although ethanol had no direct effect on liver cell CINC production, conditioned medium from ethanol-treated hepatocytes induced a threefold rise in CINC production by Kupffer cells. The increase was abrogated when hepatocytes were treated with ethanol and the metabolic inhibitor 4-methylpyrazole. The results suggest that the mechanism of ethanol-induced CINC production is indirect, involving ethanol oxidation and communication between hepatocytes and Kupffer cells.