Acid and neutral triacylglycerol ester hydrolases in rat heart

Subcellular fractions from rat heart homogenates can be characterized as having acid and neutral triacylglycerol ester hydrolase (lipase) activities in addition to lipoprotein lipase activity. Perfusion of rat hearts with heparin resulted in a decrease in lipoprotein lipase activity but no change in neutral triacylglycerol ester hydrolase activity, indicating that these two lipase activities probably represent separate and distinct enzymes. A comparison of the subcellular distribution of the acid triacylglycerol ester hydrolase with a lysosomal marker enzyme (N-acetylglucosaminidase) suggests that the acid lipase originated in cardiac lysosomes.