Human lipoprotein lipase activity: Comparison of assay methods

Abstract

1. 1. A comparison is made of three enzyme preparations used for the determination of lipoprotein lipase activity in man, i.e. lipoprotein lipase activity in postheparin plasma (protamine-inhibited postheparin lipolytic activity), in acetone—ether preparations of adipose tissue biopsy specimens and in heparin eluates of such specimens. 2. 2. In a group of 14 healthy subjects, examined by these three techniques in the fasting and post-alimentary state, there was a correlation between enzyme activities determined in acetone—ether preparations and in heparin eluates of adipose tissue. Lipoprotein lipase activity in postheparin plasma was not correlated to lipoprotein lipase activity in adipose tissue. 3. 3. Lipoprotein lipase activity of adipose tissue was significantly higher in the post-alimentary state. Women had significantly higher values than men. 4. 4. In vitro experiments indicated that the lipoprotein lipase activity measured in heparin eluates reflects not only elution of preformed enzyme activity from the adipose tissue, but the combined effects of rates of release, activation and inactivation of the enzyme, which are considerably influenced by the conditions of the elution.