The research goals of the principal investigator are directed toward two major aims: 1) A better understanding of the turnover and homeostatic control of plasma lipoproteins in normal humans and its alteration in disease states; and 2) A definition of the structure of normal lipoproteins and the changes in lipoprotein structure which occur with disease. These objectives will be pursued to an extent which is practical with in vivo human studies. For more extensive data primate studies will be performed, as well as isolated hepatic perfusions of primates.