THE DIFFERENCES OF SERUM CHOLESTEROL AND LIPOPROTEINS IN ANIMALS SUSCEPTIBLE AND NONSUSCEPTIBLE TO ATHEROSCLEROSIS

The differences of serum lipid and lipoprotein (LP,profiles of animals susceptible (rabbit)and nonsusceptible (Beijing duck) to atherosclerosis as well as the distribution of apolipo-protein (apo) A-I and its catabolism in vivo were studied.Eight items,i.e.total cholesterol(TC),high density lipoprotein (HDL) cholesterol,triglyceride,percentage of a-LP and β-LP,β-LP concentration,lecithin cholesterol acyl transferase (LCAT),and agarose and polyacryla-mide gel electrophoresis of both species were assayed before and after feeding a high fat,high cholesterol diet.Results indicate that the exogenous cholesterol consumed by Beijingducks was carried and transported by HDL,while that in rabbits was transported by lowdensity lipoprotein (LDL).The biological half lives of apo A-I in serum and in HDL were41.11±2.4 and 42.8±1.7 h respectively.and its distribution in different organs was in theorder of liver>kidney>spleen>lung>heart>intestine>muscles>aorta.These resultsshow that the liver is the major organ for metabolizing HDL apo A-I.and the kidneyis also important.The results also imply that in Beijing ducks the cholesterol carried byHDL may be catabolized through apo A-I receptors in the liver and kidney.The differencesin cholesterol binding and in lipoprotein and apolipoprotein metabolism of the two speciesprovide important clues for the elucidation of the pathogenesis of atherosclerosis.