Serum activities of classes I and II alcohol dehydrogenases in toxic liver damage.

The activities of classes I and II alcohol dehydrogenase isoenzymes were determined in the sera of patients with toxic hepatitis using class-specific fluorogenic substrates. The activities of total alcohol dehydrogenase and enzymes indicative of liver damage were also measured. We found a statistically significant increase of class I alcohol dehydrogenase isoenzymes. The increase in class I (two-fold) was similar to the increase of alkaline phosphatase. In a correlated study, we observed a good correlation of the activity of class II isoenzymes with alanine aminotransferase. The total alcohol dehydrogenase activity was enhanced and correlated with lactate dehydrogenase. These results demonstrated that the alcohol dehydrogenase and class I isoenzymes are indicatory enzymes of liver cell damage, and may be diagnostically useful in toxic hepatitis.