Oxidative Stress and Membrane Fluidity of Red Blood Cells in Hypertensive and Normotensive Men An Electron Spin Resonance Investigation

Abstract

SummaryRecent evidence indicates that oxidative stress might actively participate in the pathophysiology of hypertension, atherosclerosis, and other cardiovascular diseases. The purpose of the present study was to assess the possible link between oxidative stress and membrane fluidity in hypertensive and normotensive men. We measured the membrane fluidity (a reciprocal value of membrane microviscosity) of red blood cells (RBCs) in hypertensive and normotensive men using an electron spin resonance (ESR) and spin-labeling method. Membrane fluidity of RBCs was decreased in hypertensive men compared with normotensive men. The levels of plasma 8-Iso-prostaglandin F2α (8-Iso-PG F2α : an index of oxidative stress) were significantly higher in hypertensive men than in normotensive men. In contrast, plasma nitric oxide (NO)-metabolite levels were significantly lower in hypertensive men than in normotensive men. In the overall analysis of hypertensive and normotensive men, plasma 8-Iso-PG F2α levels were inversely correlated with plasma NO-metabolites. Furthermore, the reduced membrane fluidity of RBCs was associated with increased plasma 8-Iso-PG F2α and decreased plasma NO-metabolite levels. In a multivariate regression analysis, plasma 8-Iso-PG F2α was found to be an independent determinant of membrane fluidity of RBCs participate in the pathophysiology of hypertension and atherosclerosis, and might be associated with increased risk of cardiovascular diseases, vascular dysfunction, and the metabolic syndrome.1-3) Recent studies have shown that plasma 8-Iso-prostaglandin F2α (8-Iso-PG F2α ) may be a reliable index of oxidative stress in humans. [4][5][6][7] It was demonstrated that the plasma concentration of 8-Iso-PG F2α was significantly increased in subjects with essential hypertension compared with normotensive subjects. 4,5) It has also been shown that plasma 8-Iso-PG F2α levels were elevated in patients with coronary artery disease, particularly in those with hypertension. 6,7) However, cellular mechanisms of oxidative stress in the pathophysiology of hypertension are not fully understood.Abnormalities in the physical properties of the cell membranes may underlie the defects that are strongly linked to hypertension, stroke, and other cardiovascular disease conditions. 8,9) An electron spin resonance (ESR) and spinlabeling method has been developed to evaluate the membrane fluidity (a reciprocal value of membrane microviscosity) and the perturbations of membrane function by external agents. 8,9) Using the ESR method, we have been performing a series of experiments regarding the membrane fluidity in subjects with essential hypertension. [9][10][11][12][13] The results suggest that the membrane fluidity of red blood cells (RBCs) was significantly lower in hypertensive subjects than in normotensive subjects, indicating that the cell membranes were stiffer and less fluid in essential hypertension. [9][10][11][12][13] Because the deformability of RBCs may be highly dependent on the membrane fluidity, 8) the reduction in...

Vitex Agnus-Castus L. Essential Oil Increases Human Erythrocyte Membrane Fluidity

“…Hence, these results obtained in vitro are comparable to in vivo conditions, and indicate that the application of Vac essential oil may be expected to increase erythrocyte membrane fluidity in the blood of treated subjects. Since the fluidity of the erythrocyte membrane strongly affects their rheologic behavior/deformability which relate to blood pressure (11)(12)(13), Vac essential oil could be efficacious when hypertension and other cardiovascular problems related to menopause are present.…”

“…The fluidity of the erythrocyte membrane is an important determinant that modulates their rheologic behavior and is a main feature defining blood viscosity (11); this property is related to hypertensive and atherosclerotic disease. For example, the membrane fluidity of erythrocytes is reduced in both spontaneously hypertensive rats and patients with essential hypertension, when compared to normotensive controls (12,13). Also, the fatty acid profile of the erythrocyte membrane defines its physicochemical properties, i.e., fluidity/viscosity (14,15).…”

Chronic Kidney Disease Predicts Impaired Membrane Microviscosity of Red Blood Cells in Hypertensive and Normotensive Subjects

“…Eighteen male hypertensive participants and 13 male normotensive participants were the same as those in a previous study. 18) Information on medical history was obtained by interview. No participants had a history of renal disease, such as acute or chronic glomerulonephritis, nephrotic syndrome, and diabetic nephropathy, or hematologic and hepatic diseases.…”

“…11,12) Membrane fluidity is a physicochemical feature of biomembranes, and is an important factor in modulating cell rheologic behavior. 11,12) Using the ESR method, we have been performing a se-ries of experiments regarding the membrane fluidity of red blood cells (RBCs) in hypertension, and have shown that membrane fluidity was significantly lower in hypertensive subjects than in normotensive subjects, [13][14][15][16][17][18][19][20][21] indicating that the cell membranes were stiffer and less fluid in hypertension. Because the deformability of RBCs might be highly dependent on membrane fluidity, 11,12) a reduction in membrane fluidity could cause a disturbance in the blood rheologic behavior and the microcirculation, which might contribute to the pathophysiology of hypertension and other circulatory disorders.…”

Positive effects of naringenin on near-surface membrane fluidity in human erythrocytes

“…Also, the cell membrane alterations may characterize a certain blood pressure disorders (16). In this respect, it was observed that erythrocyte membrane fluidity is significantly lower in both spontaneously hypertensive rats and patients with essential hypertension, in comparison with normotensive subjects (22,23,24). Obviously, the fatty acid profile of the erythrocyte membrane together with its biophysical properties may be at least partially responsible for some cardiovascular risks (3,9).…”