Abstract
HDL can usually be divided into two subfractions, HDL-2 (1.063<d<1.125) and HDL-3 (1.125<d<1.21), but little is known about the function of these subfractions. Recently, the effects of VLDL-lipolysis upon the structure of HDL-3 was reported by Eisenberg, Patsch et al., and they have shown that HDL-3 could be converted to HDL-2-like particles. This time, we incubated whole HDL, HDL-3 and HDL-2 with VLDL separately, and obtained the following results.
(1) The lipolysis of VLDL by lipoprotein lipase was completelly inhibited by 1M-NaCl and also moderately inhibited by 1mM-DTNB (LCAT-inhibitor).
(2) When VLDL was incubated with whole HDL and HDL-3, HDL-2 increased and HDL-3 decreased on the contrary. But, HDL-3 did not increase when VLDL was incubated with HDL-2.
(3) We speculated from these experiments that HDL-3 could be converted to HDL-2 fraction during lipolysis of Very Low Density Lipoproteins.
