Lipid Composition of HDL Subfractions in Dog Plasma and Lymph

Abstract

Abstract We report the lipid composition of dog plasma and peripheral lymph lipoproteins as separated into pre-β, α, and pre-α fractions by agarose gel electrophoresis. Plasma lipoproteins with α mobility have a composition different from that of plasma lipoproteins with pre-α mobility, having 9% versus 11% free cholesterol, 21% versus 17% cholesterol ester, 1% versus 16% triacylglycerol, and 69% versus 56% phospholipid. On the other hand, lymph α and pre-α lipoproteins have compositions that are quite similar (9% versus 7% free cholesterol, 17% versus 17% cholesterol ester, 2% versus 4% triacylglycerol, and 71% versus 71% phospholipid). The lipid compositions of plasma and lymph α lipoproteins are quite similar (9% versus 9% free cholesterol, 21% versus 17% cholesterol ester, 1% versus 2% triacylglycerol, and 70% versus 72% phospholipid). The lipid compositions of plasma and lymph pre-α lipoproteins are different (11% versus 7% free cholesterol, 17% versus 17% cholesterol ester, 16% versus 4% triacylglycerol, and 56% versus 71% phospholipid). Peripheral lymph lipoproteins with pre-β mobility contained 15% cholesterol, 13% cholesterol ester, 10% triacylglycerol, and 61% phospholipid. Compared with plasma, peripheral lymph lipoproteins are free cholesterol–enriched in all fractions. Calculated stoichiometric ratios of lipid to apoA-I indicate that pre-β lipoproteins contain one molecule of apoA-I per particle, α lipoproteins have two molecules of apoA-I per particle, and pre-α lipoproteins have four molecules of apoA-I per particle.