Separation of High Density Lipoprotein (HDL) Using Anti-apo A-I, apo A-II Immuno-affinity Chromatography to Evaluate the Effects of Probucol

An assessment has been made regarding the changes of the particles of lipoprotein A-I without A-II (Lp A-I) and lipoprotein A-I with A-II (LpA-I/A-II) which correspond to HDL subfraction isolated by the use of anti-apo A-I and A-II antibody affinity columns in order to quantitatively and qualitatively investigate the change of HDL caused by administration of probucol and pravastatin which are therapeutic drugs for hypercholesterolemia. Probucol caused significant decreases of HDL- cholesterol, plasma apo A-I/apo A-II ratio and particles larger in diameter than 10.4nm. Comparing Lp A-I and A-I/A-II ratios with those in normolipidemic controls and the ratios before and after administration of probucol, the decrease of LpA-I ratio was found to be remarkable after prolonged administration of probucol, and it was presumed that the decrease of HDL cholesterol by prolonged administration reflects the decrease of LpA-I particles more than the decrease of LpA-I/A-II. On the other hand, no significant change was seen in HDL cholesterol, plasma apo A-I/apo A-II ratio or HDL particle size in the pravastatin group. It is considered essential to observe HDL from the aspect of apoprotein, which plays an important role in the metabolism of lipoprotein, in the assessment of the anti-atherogenic activity of HDL cholesterol in future. In other words, it is necessary to analyze the change of HDL from the aspect of Lp A-I and Lp A-I/AII and investigate their respective metabolisms and roles.