Abstract
The effect of heparin-induced lipolysis on the high density lipoprotein (HDL) subfractions was studied in 12 normotriglyceridemic patients (NTG) and 12 mildly hypertriglyceridemic patients (HTG). HDL2 and HDL3 were separated by ultracentrifugation before and 10min after heparin (10 units/kg of body weight) injection intravenously. In all subjects, there were negative correlations among the changes of VLDL- and HDL2-lipid levels after heparin injection. The changes of HDL2-lipid levels, except for triglyceride (TG), were inversely correlated with those of HDL3-lipid levels. These results supported that the conversion of HDL3 to HDL2 was induced during lipolysis of triglyceriderich lipoproteins (TGRLP) in vivo. In HTG, TG, free cholesterol (FC) and phospholipid (PL) in HDL2 increased significantly and esterified cholesterol (EC) and PL in HDL3 decreased significantly after heparin injection. In NTG, however, EC and PL in HDL2 decreased significantly and PL in HDL3 increased significantly after heparin injection. NTG differed from HTG in the heparininduced changes of HDL subfractions. In this experiment, it is not confirmed whether this difference is due to only the difference of TGRLP level between in NTG and HTG.