Isoenzymes of class I and II alcohol dehydrogenase in chronic hepatitis.

Using class-specific fluorogenic substrates, the activities of class I and II alcohol dehydrogenase (ADH) isoenzymes were determined in the sera of patients with chronic hepatitis. The activity of the total alcohol dehydrogenase and indicator enzymes of liver damage were also investigated. We found a statistically significant increase of class I alcohol dehydrogenase isoenzymes in the total tested group which included those with the viral hepatitis. The (2-fold) increase in the activity of class I isoenzymes was similar to the increase of aminotransferases. The serum activity of class II isoenzymes was unchanged. Here an increase in total enzyme activity was not statistically significant. Class I isoenzymes and total enzyme activity correlated well with aminotransferases. These results demonstrate that serum activity of class I ADH measured with fluorogenic substrates confirms liver cell damage and may be useful in the diagnosis of chronic hepatitis.