Effects of probucol and pravastatin on plasma lipids, activities of postheparin lipoprotein lipase, and lecithin cholesterol acyltransferase and apo A-i containing lipoproteins with and without apo A-Ii in patients with moderate hypercholesterolemia
Kagami, A.; Ishikawa, T.; Tada, N.; Sakamoto, T.; Mochizuki, K.; Nagano, M.; Moriguchi, E.H.; Manabe, M.
Clinical Biochemistry 26(2): 101-107
ISSN/ISBN: 0009-9120 PMID: 8485855 DOI: 10.1016/0009-9120(93)90036-6
In this study, plasma HDL fractions were separated by ultracentrifugation and apo A-I containing lipoproteins (A-I Lp) were then isolated using anti-apo A-I immunoaffinity chromatography. The A-I Lp were further separated into two fractions with the use of anti-apo A-II immunoaffinity chromatography. One fraction, Lp A-I, contained apo A-I without apo A-II, while the other, Lp A-I/A-II, contained both apo A-I and apo A-II. These techniques were applied to investigate the changes in HDL apoprotein composition in hypercholesterolemic subjects treated with either probucol or pravastatin. Treatment with probucol (500 mg/day) or pravastatin (10 mg/day) reduced mean plasma total cholesterol concentrations by 24% (p < 0.01) and 16% (p < 0.05), respectively. Both drugs caused some reduction in lipoprotein lipase activity, but neither had any influence on the activity of hepatic triglyceride lipase or lecithin cholesterol acyltransferase. Their effects on HDL-cholesterol levels and apoprotein composition differed markedly. Probucol significantly decreased the HDL-cholesterol concentration, the plasma apo A-I/apo A-II ratio, and the number of large particles of diameter greater than 10.4 nm. When the ratios of Lp A-I and Lp A-I/A-II for the probucol-treated subjects were compared with those in the normolipidemic controls, and with the ratios before and after administration of probucol, a remarkable decrease in the level of Lp A-I was apparent. It is presumed that the decrease in HLD-cholesterol by prolonged probucol administration reflects the decrease of Lp A-I more than the decrease of Lp A-I/A-II.