EVIDENCE THAT REVERSE CHOLESTEROL TRANSPORT IS STIMULATED BY LIPOLYSIS OF TRIGLYCERIDE-RICH LIPOPROTEINS

The hypothesis that reverse cholesterol transport by high density lipoprotein (HDL) is augmented by lipolysis of triglyceride-rich lipoproteins received support from experiments in rabbits whose tissue cholesterol had been pre-labeled with [H-3]cholesterol several weeks earlier. When lipolysis was stimulated by intravenous heparin (which releases lipoprotein lipase from vascular endothelium), reciprocal changes in plasma triglyceride and HDL cholesterol concentrations were accompanied by a rise in the specific radioactivity of HDL cholesterol, indicative of increased transfer of cholesterol into HDL from slowly exchanging cholesterol pools in extra-hepatic tissues.