An assay has been developed for specific measurement of two different lipase activities in postheparin plasma. Lipoprotein lipase, derived from extrahepatic sources, is measured as protamine-inactivated lipase activity; hepatic lipase activity is protamine-resistant under the conditions of this assay. In 100 normal subjects, both enzyme activities were noted to be related to age and sex. Protam...

An underlying cause of type III hyperlipoproteinemia is the presence of variant forms of apolipoprotein (apo) E that are defective in binding to apo B,E low density lipoprotein receptors. This disorder is associated almost exclusively with the apo E2/2 phenotype. However, structural and functional heterogeneity have been demonstrated within this phenotype. The apo E2(Arg158----Cys) variant, dis...

To test the hypothesis that genetic susceptibility or resistance to diet-induced atherosclerosis is correlated with serum levels of specific lipids, lipoproteins, or apoproteins, male mice of a genetically susceptible and a genetically resistant strain were fed either a normal or an atherogenic diet. After 20 weeks on a normal diet, neither the resistant nor the susceptible strain mice had athe...

Type V hyperlipoproteinemia (HLP) is characterized clinically by hepatosplenomegaly, occasional eruptive xanthomas, and an increased incidence of pancreatitis. These patients have striking hypertriglyceridemia due to increased plasma chylomicron and very low density lipoprotein concentrations in the fasting state, without a deficiency of lipoprotein lipase or its activator protein, apolipoprote...