Triglyceride lipase activity in postheparin plasma and plasma lipoproteins in liver disease

Hepatic lipase activity and lipoprotein lipase activity were studied in postheparin plasma from 14 patients with various liver disorders. Plasma lecithin: cholesterol acyltransferase (LCAT) activity and lipoprotein composition and structure were also estimated. Five patients had lower hepatic lipase activity than the lowest control value, and in three of these no hepatic lipase activity was detected. Lipoprotein lipase was low in 5 patients, but in only one of them was hepatic lipase activity also low. Hepatic lipase was not significantly correlated to the concentration of plasma triglycerides, either in controls or in patients, whereas lipoprotein lipase was negatively correlated with plasma triglycerides both in controls and patients. Lipoprotein lipase and LCAT activity, but not hepatic lipase, was negatively correlated to the triglyceride content of the low density lipoproteins (density 1.019-1.063 g/ml) from the patients. No specific lipid or lipoprotein pattern was found in plasma from the patients with a low or without any hepatic lipase activity. The results suggest an important role of lipoprotein lipase and LCAT, for the increased content of triglycerides in the low density lipoproteins in patients with liver disease. The role of hepatic lipase remains unclear.