In situ distribution of enolase isozymes in chronic liver disease

Liver biopsy specimens with or without chronic liver diseases were examined immunohistochemically to determine the distribution of enolase isozymes (alpha, beta, and gamma). In normal liver, alpha-enolase was positively stained in almost all hepatocytes and bile duct cells. beta- and gamma-enolases were localized in hepatocytes and bile duct cells, respectively. Electron microscopic studies revealed that Kupffer cells and sinusoidal endothelial cells had both alpha- and gamma-enolases. In chronic active hepatitis and cirrhosis, proliferated biliary ductular cells had both alpha- and gamma-enolases, but did not express beta-enolase. This is almost the same localization pattern of enolase isozymes as in preexisting bile duct cells. gamma-Enolase was detected in some hepatocytes in eight of 12 cases with chronic active hepatitis and six of 12 cases with cirrhosis. These hepatocytes were small, showed a cobblestone pattern, and binucleate cells were frequent. On the other hand, rosette-formed hepatocytes adjacent to a regenerating bulging lobule were not stained for gamma-enolase. These results suggest that regenerating hepatocytes have gamma-enolase and that, with maturation, hepatocytes lose it.