B-21. 高脂血症と赤血球変形

抄録

To detect perturbations of the membrane structure and properties of mammalian erythrocyte induced by increased lipid content of the blood plasma, cellular shape changes based on conformational change of the membrane was utilized as the sensitive indicator.
Erythrocytes from genetic “fatty” rat with remarkable increased VLDL level or those from nephrotic patients with increased LDL level, did not show any appreciable shape change. In contrast, elevation of the plasma level of lysolecithin or free fatty acid induced varying degrees of echinocyte-spherocyte shape change, depending on the amount of the free lipid (s) incorporated into the membrane, which was accompanied by the changes in the membrane surface area, surface charge, osmotic fragility, etc. Partial removal of these membrane lipids normally present in the erythrocyte membrane induced a stomatocyte-type shape change.
From these results and from consideration of the known clinical findings on the abnormally -shaped erythrocytes in some hepatobiliary diseases and particularly in lipoprotein X cases, importance of the plasma level of the free lipids such as lysolecithin, free fatty acid and bile acids in inducing membrane perturbations on erythrocytes, and probably of some tissue cells, was emphasized. These lipids may act as “protein stabilizers” or “detergents” to give powerful effect on the membrane constituents. In contrast, the plasma lipoproteins may behave as a kind of “membrane” to fuse with the erythrocyte membrane in the presence of “detergent” lipid or to exchange the lipid constituents with it only under limited circumstances.