1. Differential release of hepatic lipolytic activities
- Author
-
M.C. Oerlemans, W.C. Hülsmann, and Hans Jansen
- Subjects
Male ,Biophysics ,Biochemistry ,Phospholipase A1 ,Hydrolase ,Animals ,Hepatectomy ,Molecular Biology ,Triglycerides ,chemistry.chemical_classification ,Antiserum ,Immunoassay ,Heparin ,Lipid Mobilization ,Triacylglycerol Hydrolase ,Cell Biology ,Lipase ,Molecular biology ,Monoacylglycerol Lipases ,Rats ,Monoacylglycerol lipase ,Perfusion ,Kinetics ,Liver lipase ,Enzyme ,chemistry ,Liver ,Phospholipases ,Rat liver ,lipids (amino acids, peptides, and proteins) ,Carboxylic Ester Hydrolases - Abstract
Summary Perfusion of rat liver with a heparin-containing medium results in a release of upto 95% of the total neutral (or alkaline) triacylglycerol hydrolase activity (EC 3.1.1.3). Of the monoacylglycerol hydrolase (EC 3.1.1.23), phospholipase A1 (EC 3..1.1.32) and palmitoyl-CoA hydrolase (EC 3.1.2.2) activities only 17 to 4% were found to be heparin-releasable. Antiserum raised against heparin-releasable liver lipase inhibits triacylglycerol hydrolase, monoacylglycerol hydrolase, palmitoyl-CoA hydrolase and phospholipase A1 activities in perfusates of isolated livers completely. Non-heparin-releasable monoacylglycerol hydrolase, palmitoyl-CoA hydrolase and phospholipase A1 activities are not inhibited by the antiserum and are therefore catalyzed by different enzyme(s). The difference in substrate specificities of releasable and nonreleasable liver enzymes is discussed in relation to their possible function in lipoprotein metabolism.
- Published
- 1977