Affiliations:
Department of Physiology, Medical School, Ehime University, Shigenobu, Onsen-gun, Ehime 791-02, Japan
Abstract: Effects of artificially augmented membrane cholesterol on red cell functions (rheology and oxygen transport) were studied. As increasing the cholesterol content of human red cells by incubation with phospholipid vesicles containing cholesterol, the following dysfunctions were observed. 1) The decreased membrane fluidity as monitored by spin label motion. 2) The decreased deformability, due to hardening of lipid membrane. 3) The increased suspension viscosity, due to decreasing of deformability. 4) The retardation of oxygen release from red cells, inspite of constant oxygen affinity, due to the augmented oxygen diffusion barrier. In addition, the influence of cross-linked membrane proteins on membrane lipids was de- scribed. The degrees of dysfunctions induced by excess membrane cholesterol were roughly quantified, and the phenomena were explained on the basis of molecular interaction of cholesterol in membrane.
Keywords: Cholesterol, red cell deformability, red cell functions, membrane fluidity, suspension viscosity, xygen release
