LIPOPROTEIN AND APOPROTEIN PROFILES OF HYPERLIPIDEMIC ATHEROSCLEROSIS-PRONE JAPANESE-QUAIL

The purpose of this study was to characterize the lipoprotein and apop rotein profiles of hyperlipidemic atherosclerosis-prone (HAP) Japanese quail. HAP and commercially available (CA) Japanese quail were fed ei ther a semi-purified diet containing 1% cholesterol or a cholesterol-f ree diet for two weeks. The lipoproteins of CA and HAP quail fed chole sterol-free diet were composed of two fractions: densities ranging fro m 1.02 to 1.09 and from 1.09 to 1.21. The lipoprotein distribution pat terns obtained from both strains showed an HDL-predominant pattern. A protein of 26 kDa was the major apoprotein in the entire density range of the lipoprotein class. Marked increases in the cholesterol ester l evels were observed in the lower density fractions (1.006<d<1.055: chy lomicron and VLDL fractions) of the cholesterol-fed quail, accounting for 46% of the total lipids in CA quail and 54% in HAP quail. In addit ion, the presence of a protein of 470 kDa was exclusively observed in the lower density fractions (1.006<d<1.055) of the cholesterol-fed HAP quail. The fatty-acid compositions of the chylomicron and VLDL fracti ons were affected by the dietary cholesterol in both strains: a decrea se in concentration of 16:0 and increase in 18:0 (weight %). However, cholesterol feeding had no effect on the level of cholesterol, chemica l composition or fatty-acid composition of the HDL fractions in either strain. Although the lipoprotein and apoprotein profiles of HAP quail showed resemblances to those of the CA quail, expression of the 470 k Da protein in the lipoproteins (d < 1.055) appeared to be pronounced i n HAP quail. The relevance of these lipoprotein and apoprotein profile s to the genesis of atherosclerosis was discussed in this study.