摘要
Oxidized low density lipoprotein (LDL) has been shown to inhibit the activity of platelet plasma mambrane Ca^2+ ATPase, and induce changes of factin in endothelial cells. Since the deformability of human erythrocytes are closely related to the calcium metabolism and the stability of cytoskeleton, the influence of oxidized LDL on plasma membrane Ca^2+ ATPase and plasma membrane fluidity were studied in human erythrocytes. Our in vitro experiments demonstrated that oxidized LDL, but not native LDL, inhibits the activity of Platelet Research Unit, Institute of Anatomy, University of Münster, Germany (Zhao B, Filler TJ and Dierichs R) Shanghai Fourth People's Hospital, Shanghai, China (Yu H) Department of Biochemistry, University of Louisville, Kentucky, USA (Dean W)Ca^2+ ATPase in purified erythrocyte plasma membrane (P<0.01). Since no change in the membrane fluidity was detected in the erythrocyte plasma membrane exposed to native LDL and oxidized LDL as estimated by steady state by trimthylammonium diphenylhexatriene (TMA DPH) anisotropy, oxidized LDL did not affect the Ca^2+ ATPase by grossly changing the erythrocyte deformability probably by interfering the cytosolic calcium and then altering the cytoskeleton. The deformability of erythrocytes is important in microcirculation. A better understanding of the interactions between oxidized LDL, erythrocytes, platelets and endothelial cells can prevent cardiovascular diseases.
Oxidized low density lipoprotein (LDL) has been shown to inhibit the activity of platelet plasma mambrane Ca^2+ ATPase, and induce changes of factin in endothelial cells. Since the deformability of human erythrocytes are closely related to the calcium metabolism and the stability of cytoskeleton, the influence of oxidized LDL on plasma membrane Ca^2+ ATPase and plasma membrane fluidity were studied in human erythrocytes. Our in vitro experiments demonstrated that oxidized LDL, but not native LDL, inhibits the activity of Platelet Research Unit, Institute of Anatomy, University of Münster, Germany (Zhao B, Filler TJ and Dierichs R) Shanghai Fourth People's Hospital, Shanghai, China (Yu H) Department of Biochemistry, University of Louisville, Kentucky, USA (Dean W)Ca^2+ ATPase in purified erythrocyte plasma membrane (P<0.01). Since no change in the membrane fluidity was detected in the erythrocyte plasma membrane exposed to native LDL and oxidized LDL as estimated by steady state by trimthylammonium diphenylhexatriene (TMA DPH) anisotropy, oxidized LDL did not affect the Ca^2+ ATPase by grossly changing the erythrocyte deformability probably by interfering the cytosolic calcium and then altering the cytoskeleton. The deformability of erythrocytes is important in microcirculation. A better understanding of the interactions between oxidized LDL, erythrocytes, platelets and endothelial cells can prevent cardiovascular diseases.
