High-density lipoprotein subfractions as measured by differential polyanionic precipitation and rate zonal ultracentrifugation.

Recent interest in the putative protective role of high-density lipoprotein (HDL) and its subfractions against atherosclerosis has highlighted the need for a rapid, simple subfractionation procedure. Here we compared HDL subfractionation by two recently developed polyanionic-precipitation methods with the values obtained by rate zonal ultracentrifugation. A similar result for total HDL cholesterol was obtained by all three methods. However, HDL2 cholesterol as measured by the precipitation procedures was significantly higher than the zonal value, and HDL3 was lower. This reflects the different underlying principles involved in the separations and highlights the need for a clearer understanding of the functional roles of the HDL fractions.