Abstract
Using a method of ultracentrifugation which brings out clearly the α and β lipoprotein components of serum, studies of normal, hypertensive and nephrotic human beings have been made. There are striking differences in distribution of lipoproteins among the different ages and sexes. During the stages of active atherogenesis in hypertensives and nephrotics, both the α and β lipoproteins and the lighter, higher molecular weight aggregates contribute importantly to the superabundance of plasma lipoproteins. The attribution of an exclusive atherogenesis to any one plasma fraction does not seem to us justified by these or other studies.