Tsuda K, Nishio I, Masuyama Y
Department of Medicine, Wakayama Medical College, Japan.
Am J Hypertens. 1997 Dec;10(12 Pt 1):1411-4. doi: 10.1016/s0895-7061(97)00365-8.
To determine a possible role of sodium-potassium adenosine triphosphatase (Na+, K+-ATPase) in the regulation of membrane functions in hypertension, we investigated the effects of ouabain on the membrane fluidity of erythrocytes in spontaneously hypertensive rats (SHR) by means of an electron paramagnetic resonance (EPR) and spin labeling method. Erythrocytes obtained from SHR were examined compared with age matched Wistar-Kyoto (WKY) rats, and the EPR spectra for 5-nitroxide stearate incorporated into the erythrocyte membranes were studied. The value of order parameter (S) of the EPR spectra was significantly higher in the erythrocytes of SHR than in the erythrocytes of WKY rats (S value: SHR, 0.721+/-0.009, n = 10; WKY, 0.652+/-0.008, n = 10; P < .05). The finding shows that the membrane fluidity of erythrocytes was lower in SHR than in WKY rats. Ouabain loading to erythrocytes significantly decreased the membrane fluidity (S value was increased) in both SHR and WKY rats. The ouabain induced change was significantly greater in SHR than in WKY rats. These results demonstrate that the membrane fluidity of erythrocytes might be highly dependent on the Na+, K+-ATPase activity in SHR, which would suggest an abnormality in Na+ related cellular functions in hypertension.
为了确定钠钾三磷酸腺苷酶（Na +，K + -ATP酶）在高血压膜功能调节中的可能作用，我们通过电子顺磁共振（EPR）和自旋标记方法研究了哇巴因对自发性高血压大鼠（SHR）红细胞膜流动性的影响。将SHR获得的红细胞与年龄匹配的Wistar-Kyoto（WKY）大鼠进行比较，并研究掺入红细胞膜中的5-硝基硬脂酸盐的EPR光谱。SHR红细胞的EPR光谱的有序参数（S）值显著高于WKY大鼠的红细胞（S值：SHR，0.721±0.009，n = 10；WKY，0.652±0.008，n = 10；P <.05）。该发现表明，SHR红细胞的膜流动性低于WKY大鼠。向红细胞中加载哇巴因显著降低了SHR和WKY大鼠的膜流动性（S值增加）。哇巴因诱导的变化在SHR中比在WKY大鼠中显著更大。这些结果表明，SHR中红细胞的膜流动性可能高度依赖于Na +，K + -ATP酶活性，这表明高血压中与Na +相关的细胞功能存在异常。
