Production of chemotactic activity for polymorphonuclear leukocytes by cultured rat hepatocytes exposed to ethanol.

Abstract

Acute alcoholic hepatitis is characterized by infiltration of the liver parenchyma with polymorphonuclear leukocytes. As a possible explanation for this phenomenon, we have found that ethanol stimulates cultured rat hepatocytes to generate potent chemotactic activity. Hepatocytes (greater than 99% pure), isolated from the livers of Sprague-Dawley rats, responded to incubation with ethanol (2.0-10 mM) by releasing chemotactic activity for human polymorphonuclear leukocytes into culture supernatants in a time- and concentration-dependent fashion. Chemotactic activity was maximal after incubation of hepatocytes with 10 mM ethanol for 6 h. It was undetectable in the absence of ethanol and was reduced in the presence of either the alcohol dehydrogenase inhibitor, 4-methylpyrazole, or the acetaldehyde dehydrogenase inhibitor, cyanamide. Ethanol failed to stimulate generation of chemotactic activity by either rat dermal fibroblasts, hepatic sinusoidal endothelial cells, or Kupffer cells. The chemotactic activity generated by ethanol-treated rat hepatocytes was recovered from culture supernatants in the lipid phase after extraction with chloroform/methanol. Thin-layer chromatography and high performance liquid chromatography of chloroform/methanol extracts demonstrated that the chemotactic factor probably is a polar lipid. This chemotactic lipid may account, in part, for the leukocytic infiltration of the liver parenchyma that is observed during the course of acute alcoholic hepatitis.