Serum alcohol dehydrogenase activity in liver diseases AHLAM A KHAYROLLAH,' " Y Y AL-TAMER,' " M TAKA,t AND

SUMMARY The normal level of human serum alcohol dehydrogenase (EC l.l.l.l) (ADH) activity which is not measurable by conventional methods was found to be within the range 0·07-0·56 VII when measured by a sensitive method based on a coenzyme recycling reaction. In different liver diseases the normal upper limit of serum ADH activity was found to be exceeded up to 70 times. Although ADH activity under pathological conditions usually parallels that of other enzymes, e.g., sorbitol dehydrogenase (EC 1.l.l.l4) (SDH) and alanine transaminase (EC 2.6.1.2) (ALT), its relative elevation above the upper normal limit is generally greater, particularly in the early stages of viral hepatitis. Observations on some patients also suggested that very early stages of liver damage, caused by drugs or secondary malignancy, could be detected by increases of serum ADH activity when the activities of some other liver specific enzymes were still within their normal values. A pilot experiment on rats, intoxicated with carbon tetrachloride, showed that serum ADH activity could reflect acute liver parenchymal damage more sensitively than SDH and ALT activity. Alcohol dehydrogenase (alcohol: NAD+ oxido-reductase, Ee 1.1.1.1) (ADH) has broad sub-strate specificity- in man and is confined almos