The ratio glycerophospholipids/free cholesterol of human serum: a possible parameter of asymmetric fluidity of lipoprotein molecules

The ratio glycerophospholipids/free cholesterol in serum is proposed as a parameter sufficiently easy to be used in routine clinical work. The possible importance of this ratio in the regulation of blood lipoprotein concentration is discussed and special attention has been paid to the asymmetry of the PC and free cholesterol association in the secretion, interconversion and removal of lipoproteins from blood. Many proposals are offered as a working hypothesis for studying the factors involved in the regulation of blood lipoprotein concentration.