The effect of elective surgery on serum N-acetyl-beta-D-glucosaminidase activity

N-acetyl-beta-D-glucosaminidase (NAG; EC 3.2.1.30) activity was measured in sera of 23 patients admitted for elective surgery. Cholecystectomy increased serum NAG activity (by 62%) (p less than 0.004), whereas other types of operations (minor or major abdominal surgery, inguinal hernias and leg varices) had no regular effect. In cholecystectomy patients, the increase of serum NAG activity was associated with parallel changes in liver enzymes suggesting that manipulation of liver may liberate NAG into the circulation. Surgical trauma per se does not provoke any significant liberation of NAG.