HDL biology
Medium-chain saturated fatty acids boost CETP-driven formation of very small HDL particles, while arachidonic acid blocks it (Biochim Biophys Acta 1991)
Original title: Effects of various non-esterified fatty acids on the particle size redistribution of high density lipoproteins induced by the human cholesteryl ester transfer protein
The effects of various non-esterified fatty acids on CETP-mediated HDL particle size redistribution were studied by incubating HDL3 and CETP for 24 hours at 37 degrees C with or without saturated, monounsaturated, or polyunsaturated fatty acids. Without fatty acids, CETP redistributed the initial HDL3 population (Stokes radius 4.3 nm) into one larger (4.8 nm) and two smaller (3.9 and 3.7 nm) subpopulations. Fatty acids alone did not alter the HDL3 profile, but markedly changed the ability of CETP to redistribute particle sizes. Saturated fatty acids with at least 10 carbons increased formation of the very small 3.7-nm particles in a concentration-dependent manner, with 12- and 14-carbon chains the best activators. At higher concentration (0.4 mmol/l), oleic, linoleic, and arachidonic acids instead decreased formation of the 3.7-nm particles, with arachidonic acid the strongest inhibitor.
Original abstract
The effects of various non-esterified fatty acids on the CETP-mediated particle size redistribution of HDL were studied by incubating HDL3 and CETP for 24 h at 37 degrees C in the absence or in the presence of either saturated, monounsaturated or polyunsaturated non-esterified fatty acids. In the absence of non-esterified fatty acids, CETP induced a redistribution of the initial population of HDL3 (Stokes' radius 4.3 nm) by promoting the appearance of one larger (Stokes' radius 4.8 nm) and two smaller (Stokes' radii 3.9 and 3.7 nm) HDL subpopulations. Whereas the non-esterified fatty acids alone did not modify the HDL3 distribution profile, they were able to alter markedly the capacity of CETP to induce the particle size redistribution of HDL. All the saturated fatty acids with at least 10 carbons were able to increase the formation of the very small sized particles (Stokes' radius 3.7 nm) in a concentration dependent manner, the medium chain fatty acids (12 and 14 carbons) being the best activators. The potential effect of non-esterified fatty acids was also influenced by the presence of double bonds in their monomeric carbon chain. While at low concentrations of non-esterified fatty acids (0.1 mmol/l) the enhancement of the formation of very small HDL particles appeared to be greater with oleic and linoleic acids than with stearic acid, at higher concentrations (0.4 mmol/l), oleic, linoleic and arachidonic acids decreased the formation of the 3.7 nm radius particles. The inhibition of the process at high concentrations of unsaturated fatty acids was linked to the degree of unsaturation of their carbon chain, arachidonic acid being the strongest inhibitor. The present study has demonstrated that non-esterified fatty acids can modulate the particle size redistribution of HDL3 mediated by the cholesteryl ester transfer protein even in the absence of any other lipoprotein classes. The effect of non-esterified fatty acid is dependent on both the length and the degree of unsaturation of their monomeric carbon chain.
Summary written by cetpinhibition.org from the published abstract; figures as published. Page updated 19 August 2026. Methods.