Immunochemical assay of rat postheparin plasma triacylglycerol lipases

Immunochemical methods for selective measurement of lipoprotein lipase and hepatic lipase activities in rat postheparin plasma are described and validated. Lipoprotein lipase was measured using a substrate containing 10% serum and 0.1 M NaCl after inactivation of hepatic lipase with a specific antiserum. Hepatic lipase was measured at 1.0 M NaCl with a serum-free substrate. The heparin dose-response curve indicated maximum relase of both activities at a heparin dose of 500 IU/kg. The lipase activities in rat postheparin plasma were 3 to 4-fold higher than those in human postheparin plasma. The LPL activity in female rats was significantly higher than in males whereas there was no sex difference for hapatic lipase.