Elevated serum xanthine oxidase activity following biliary tract and gastric surgery.

The activity of serum xanthine oxidase, an enzyme mainly found in the liver, was determined in a random series of patients who underwent abdominal surgery of varying severity. Enzyme activity rose markedly on completion of operation in almost all patients undergoing biliary tract and gastric surgery, but not in those undergoing surgery of other abdominal organs, Serum glutamic oxaloacetic transaminase level rose to a smaller degree and in a smaller proportion of the patients. Elevation of the serum level of both enzymes following biliary and gastric surgery reflects hepatocellular damage caused by surgical trauma to the liver.