Abnormalities in Membrane Function and Ca-Metabolism in Hypertension, and Their Contribution to the Pathophysiology of the Metabolic Syndrome

为了评估代谢综合征的膜异常，我们研究了代谢综合征患者膜流动性的血管活性物质。膜流动性是生物膜的一种物理化学特征，是调节微循环的重要因素。利用电子顺磁共振和自旋标记方法，研究了高血压合并肥胖和糖尿病患者红细胞膜流动性的变化。我们发现血浆胰岛素水平越高，红细胞的膜流动性越低。这可能表明高胰岛素血症参与了红细胞膜流动性的调节。红细胞膜流动性的降低可能引起血液流变学行为和微循环的紊乱，这可能至少在一定程度上有助于高血压的病理生理。一种假设是胰岛素可能会加速高胰岛素血症患者的血管并发症。另一方面，红细胞膜流动性降低与血浆一氧化氮（NO）降低和不对称二甲基精氨酸（ADMA）升高有关。此外，血浆脂联素水平越低，红细胞的膜流动性越低。在这种情况下，我们强烈建议，膜功能异常及其血管活性物质的调节可能至少在一定程度上导致高血压和代谢综合征的病理生理。

In order to assess the membrane abnormalities in the metabolic syndrome, we investigated the vasoactive substances on the membrane fluidity in subjects with the metabolic syndrome. Membrane fluidity is a physicochemical feature of biomembranes and is an important factor modulating microcirculation. Using the electron paramagnetic resonance and spin-labeling method, we examine the alterations in membrane fluidity of erythrocytes in hypertensive subjects with obesity and diabetes mellitus. We demonstrated that the higher plasma insulin level, the lower the membrane fluidity of erythrocytes. This might indicate that hyperinsulinemia is involved in the regulation of membrane fluidity of erythrocytes. The decreased membrane fluidity of erythrocytes might cause a disturbance in the blood rheologic behavior and the microcirculation, which could contribute, at least in part, to the pathophysiology of hypertension. One hypothesis is that insulin might accelerate the vascular complications in subjects with hyperinsulinemia. On the other hand, it was demonstrated that the reduced membrane fluidity of erythrocytes was associated with lower plasma nitric oxide (NO) and higher asymmetric dimethyl arginine (ADMA) levels. Furthermore, the lower the plasma adiponectin levels, the lower the membrane fluidity of erythrocytes.In this context, it is strongly suggested that abnormalities in membrane function and their regulation by vasoactive substances might contribute, at least in part, to the pathophysiology of hypertension and the metabolic syndrome.