Measurement of serum alcohol dehydrogenase activity at different pH-values during the course of viral hepatitis in children.

Serum alcohol dehydrogenase activity was estimated at pH 10.4 (optimum for the typical liver isoenzyme), 8.8 (optimum for atypical liver isoenzyme), at the physiological serum pH of 7.4, and at pH 9.2, with a view to obtaining the greatest possible difference between patients and controls. Measurements were performed on the sera of 39 children aged from 2 to 13 years, using the Technicon analyzer RA-1000 with the continuously measuring method of Bonnichsen & Brink. Blood sera were tested at the onset of viral hepatitis, in the first week of hospitalization, and three times thereafter at intervals of 7 to 9 days. During the illness, the activity of serum alcohol dehydrogenase, measured at different pH-values, was higher than that of controls. The ratio of activity at pH 10.4 to activity at pH 8.8 in the sera differed from that previously reported for liver cells. The highest increase in alcohol dehydrogenase activity was at pH 9.2. The diagnostic sensitivity of alcohol dehydrogenase determination at this pH is lower than that of alanine aminotransferase, gamma-glutamyltransferase and aspartate amino-transferase, but higher than that of lactate dehydrogenase, alkaline phosphatase and bilirubin; alcohol dehydrogenase activity also shows the best correlation with the activity of gamma-glutamyltransferase.