Correlation between post‐heparin lipase and phospholipase activities in human plasma

The hypothesis that a single lipolytic enzyme in post‐heparin plasma effects the hydrolysis of both triglyceride and phospholipid was tested. After intravenous heparin, activity in plasma with the two substrate classes appeared and disappeared in parallel. The activities were not separable by the fractionation methods of zone electrophoresis, gel filtration, anion‐exchange, ultracentrifugation, or by combinations of these techniques. The degree of purification of the two activities with the use ofn‐butanol was similar. Lipolytic activity appeared to be associated with a large high density molecular aggregate. However, the concept of a single post‐heparin enzyme does not explain all the observations since the ratio of activity with triglyceride substrate to activity with phospholipid substrate decreased markedly in some subjects after increased amounts of intravenous heparin.