Biphasic control of polymorphonuclear cell migration by Kupffer cells. Effect of exposure to metabolic products of ethanol.

In order to investigate the role of the Kupffer cells in the regulation of the inflammatory reaction seen in alcoholic hepatitis, rat liver Kupffer cells were cultured and exposed to products of ethanol metabolism. The resultant supernatants were tested to study their ability to stimulate or inhibit polymorphonuclear cell chemotaxis. Kupffer cells produced increased chemokinetic activity for human polymorphonuclear leukocytes (84 +/- 6 vs. 61 +/- 4 randomly migrating cells per 5 high power fields; p less than 0.01); when incubated with soluble products of microsomal peroxidation, the Kupffer cells engendered more chemokinetic activity than that produced by untreated Kupffer cells (106 +/- 6 vs. 84 +/- 6 cells per 5 high power fields; p less than 0.05). When Kupffer cells were incubated with acetaldehyde, the chemokinetic activity that appeared in the supernatant did not differ from control (51 +/- 3 vs. 61 +/- 4 randomly migrating cells per 5 high power fields; p = NS). Chemotaxis of polymorphonuclear cells was not observed when the Kupffer cell supernatants were tested by checkerboard analysis. Kupffer cells released a factor which, at different concentrations, inhibited the response of polymorphonuclear cells to the synthetic polypeptide chemotactic factor f-met-leu-phe by 47% (p less than 0.001). This effect was unchanged when the cells were exposed to acetaldehyde or to soluble products of microsomal peroxidation. Our results demonstrate that Kupffer cells are capable of stimulating or inhibiting polymorphonuclear cell chemotaxis and that some of these effects may be influenced by the products of ethanol metabolism, suggesting that Kupffer cells may play an important role in the regulation of the inflammatory reaction seen in alcoholic hepatitis.

Mammalian collagenase increases in early alcoholic liver disease and decreases with cirrhosis.

To determine if alterations in collagen degradation may contribute to the pathogenesis of fibrosis and cirrhosis, we studied the hepatic collagenase activity of 20 baboons given alcohol containing diets or control diets under carefully controlled experimental conditions. We also studied 28 patients whose livers were biopsied for diagnostic purposes. Hepatic collagenase activity was significantly increased in baboons with fatty liver compared to levels in normal, control fed animals [(1.98 +/- 0.19 vs 1.20 +/- 0.08 units (microgram collagen digested/hour/mg liver protein) +/- S.E.M., p less than 0.001)]. The increase in hepatic collagenase activity persisted at the stage of fibrosis when compared to the activity in control baboons (2.16 +/- 0.07 vs 1.20 +/- 0.08 units +/- S.E.M., p less than 0.001). A single cirrhotic baboon available for study had an hepatic collagenase activity of 1.58 units. Patients with hepatic fibrosis had significantly higher hepatic collagenase activity than those with fatty livers [(9.12 +/- 0.94 (n =14) vs 4.52 +/- 0.54 (n = 7) units +/- S.E.M., p less than 0.001)]. However, in the group with cirrhosis, hepatic collagenase was lower [(3.92 +/- 0.61 (n = 7) units +/- S.E.M., p less than 0.001)] than in the group with fibrosis. Our findings suggest that the development of cirrhosis is coincident with, or favored by a failure of hepatic collagen degradative enzymes to keep pace with hepatic collagen synthesis.