5′-nucleotidase activities in sera and liver tissues of viral hepatitis patients

In order to disclose the mechanisms involving the elevation of serum 5′-nucleotidase (5′-N) activity in viral hepatitis patients, 5′-N activities in sera and liver tissues were examined in acute and chronic hepatitis patients and compared with normal controls. Serum 5′-N activities were 0.714±0.106 nanomoles adenosine/hour/mg protein in normal individuals, 1.162±0.479 in acute hepatitis patients, and 0.845±0.530 in chronic hepatitis patients. Tissue 5′-N activities were 298.8±86.7 in normal individuals, 598.1 ±198.3 in acute hepatitis patients, and 462.2±91.3 in chronic hepatitis patients. Serum 5′-N activity increased significantly in acute hepatitis patients, but not in chronic hepatitis patients. Tissue 5′-N acitivity increased in both acute and chronic hepatitis patients. The elevation of 5′-N acitivity in liver tissue was not an essential factor in the elevation of serum 5′-N levels. Other factors causing the release of 5′-N from liver tissue into the blood stream are thought to be more important. It is suggested that the shedding of plasma membrane with ecto 5′-N activity due to cell damage, or leakage of bile containing high 5′-N activity were causative factors.