A novel method for measuring human hepatic lipase activity in postheparin plasma

S. Imamura, J. Kobayashi, S. Sakasegawa, A. Nohara, K. Nakajima, M. Kawashiri, A. Inazu, M. Yamagishi, J. Koizumi, H. Mabuchi
2006 Journal of Lipid Research  
The objective of this study was to establish a hepatic lipase (HL) assay method that can be applied to automatic clinical analyzers. Seventy-four hyperlipidemic subjects (men/women 45/29) were recruited. Lipase activity was assayed measuring the increase in absorbance at 546 nm due to quinonediimine dye production. Reaction mixture R-1 contained 50 mM Tris-HCl (pH 9.5), 0.5 mM glycerol-1,2dioleate, 0.4% (unless otherwise noted) polyoxyethylenenonylphenylether, 3 mM ATP, 3 mM MgCl 2 , 1.5 mM
more » ... MgCl 2 , 1.5 mM CaCl 2 , monoacylglycerol-specific lipase, glycerol kinase, glycerol-3-phosphate oxidase, 0.075% N,N-bis-(4-sulfobutyl)-3methylaniline-2 Na, peroxidase, ascorbic acid oxidase. Reaction mixture R-2 contained 50 mM Tris-HCl (pH9.5), 0.15% 4-aminoantypirine. Automated assay for activity was performed with a Model 7080 Hitachi analyzer. In the lipase assay, 160 ml of R-1 was incubated at 37jC with 3 ml of samples for 5 min, and 80 ml of R-2 was added. Within-run coefficient of variations was 0.9-1.0%. Calibration curve of lipase activity was linear (r 5 0.999) between 0 and 320 U/l. Analytical recoveries of purified HL added to plasma were 96.6-99.8%. HL activity in postheparin plasma measured in this method had a closer correlation with HL mass by a sandwich ELISA (r 5 0.888, P , 0.0001) than those in the conventional method using [ 14 C-]triolein (r 5 0.730, P , 0.0001). This assay method for HL activity can be applied to an automatic clinical analyzer.-Imamura, S., J. Kobayashi, S. Sakasegawa, A. Nohara, K. Nakajima, M. Kawashiri, A. Inazu, M. Yamagishi, J. Koizumi, and H. Mabuchi. A novel method for measuring human hepatic lipase activity in postheparin plasma. J. Lipid Res. 2007. 48: 453-457.
doi:10.1194/jlr.d600022-jlr200 pmid:17090661 fatcat:lvkorq4vxjgt7jxvnms52e7oeu