Hyperhomocysteinemia and Increased Oxidative Stress Levels Are Associated with Impaired Membrane Fluidity of Red Blood Cells in Hypertensive and Normotensive Men: An Electron Spin Resonance Investigation

Abstract

<span>Hyperhomocysteinemia and oxidative stress may be strongly linked to hypertension, atherosclerosis and other cardio</span><span>vascular diseases. The present study was performed to investigate possible relationships among plasma total homocys</span><span>teine, plasma 8-iso-prostaglandin F2</span><i><span>α </span></i><span>(8-isoPG F2</span><i><span>α</span></i><span>: an index of oxidative stress), and membrane fluidity (a reciprocal value of membrane microviscosity) in hypertension. We measured the membrane fluidity of red blood cells (RBCs) in hypertensive and normotensive men using an electron spin resonance (ESR) and spin-labeling method. Membrane flu</span><span>idity of RBCs was significantly decreased in hypertensive men compared with normotensive men. Plasma total homo</span><span>cysteine levels were significantly higher in hypertensive men than in normotensive men, and correlated with plasma 8-isoPG F2</span><i><span>α</span></i><span>. In contrast, plasma nitric oxide (NO)-metabolites (an index of endothelial function) were lower in hyper</span><span>tensive men than in normotensive men. The reduced membrane fluidity of RBCs was associated with increased total homocysteine and plasma 8-isoPG F2</span><i><span>α </span></i><span>levels and decreased plasma NO-metabolite levels. Multivariate regression analysis showed that, after adjusting for general risk factors, plasma total homocysteine and 8-isoPG F2</span><i><span>α </span></i><span>were signifi</span><span>cant determinants of membrane fluidity of RBCs, respectively. These results suggest that hyperhomocysteinemia and oxidative stress with endothelial dysfunction might have a close correlation with impaired rheologic behavior of RBCs and circulatory disorders in hypertensive men.</span><span></span