CaィイD12+ィエD1-Metabolism and Membrane Functions in Hypertension

本研究的目的是确定钙和其他内在因素在高血压发病机制中的作用。β-内啡肽显著抑制大鼠延髓刺激诱发的去甲肾上腺素（NE）释放。β-内啡肽的作用在自发性高血压大鼠（SHR）中比在正常Wistar-Kyoto（WKY）大鼠中更弱。结果表明，β-内啡肽可能积极参与高血压交感神经活动的调节。此外，我们还检测了多巴胺D2受体在中枢神经系统乙酰胆碱（ACh）释放中的作用。外源性多巴胺和阿波莫平降低了模拟诱发的乙酰胆碱释放。SHR大鼠多巴胺D2受体活性较WKY大鼠明显减弱。结果表明多巴胺D2受体可能在高血压患者胆碱能神经活动的调节中具有潜在的作用。在接下来的一系列实验中，我们利用电子顺磁共振（EPR）方法研究了原发性高血压（EH）患者红细胞膜流动性的变化。EH患者的红细胞膜流动性低于血压正常者。肾上腺髓质素（AM）显著增加红细胞的膜流动性。前列腺素e1和二丁基cAMP可增强AM的作用。此外，AM在EH中比在正常血压的受试者中更大程度地增加了膜流动性。结果表明AM可能参与高血压病患者细胞功能的调节。近年来的研究表明，在人体高血压和实验性高血压中，全身水平的钙代谢异常。由于骨是体内钙的最大储存，我们通过双能x线吸收（DXA）方法研究了EH患者的骨矿物质密度（BMD）。DXA分析显示，与年龄匹配的正常血压受试者相比，女性EH的骨密度显著降低。此外，骨密度与收缩压呈负相关。此外，女性尿钙排泄量越大，骨密度越低。本研究结果表明，DXA提供了一个整体钙平衡的指标，并提示高血压可能与女性EH的BMD降低有关。少

The purpose of the present study was to determine the role of Ca and other intrinsic factors in the pathogenesis if hypertension.β-Endorphin significantly inhibited the stimulation-evoked norepinephrine (NE) release in rat medulla oblongata. The effect of β-endorphin was more attenuated in spontaneously hypertensive rats (SHR) than in normotensive Wistar-Kyoto(WKY) rats. The finding shows that β-endorphin might actively participate in the regulation of sympathetic nerve activity in hypertension. Additionally, we examined the of dopamine D2 receptors in acetylcholine (ACh) release in the central nervous system. Exogenously applied dopamine and apomorpine reduced the simulation-evoked ACh release. The activity of the dopamine D2 receptors in SHR was significantly more attenuated that in WKY rats. The results showed that the dopamine D2 receptors might have a potential role in the regulation of cholinergic nerve activity in hypertension.In the next series of the experiments, we studied th … More e changes in membrane fluidity of erythrocytes in patients with essential hypertension (EH) by means of an electron paramagnetic resonance (EPR) method. The erythrocyte membrane fluidity was lower in EH than in normotensive subjects. Adrenomedullin(AM) significantly increased the membrane fluidity of erythrocytes. The effect of AM was potentiated by prostaglandin E1and dibutyryl cAMP. Furthermore, AM increased the membrane fluidity to a greater extent in EH than in normotensive subjects. The results showed that AM might be involved in the regulation of cell function in hypertension.Recent studies have documenbted abnormalities in Ca-metabolism at systemic level in human hypertension as well as in experimental hypertension. Since bone is the largest store of Ca in the body, we investigated the bone mineral density (BMD) in patients with EH by means of the dual energy X-ray absorptiometric (DXA) method. DXA analysis showed a significant decrease in BMD in female EH compared with age-matched normotensive subjects. In addition , the BMD was inversely correlated with systolic blood pressure. Furthermore, the greater the urinary Ca-excretion, the lower the BMD in females. The results of the present study demonstrate the DXA provided an index of whole Ca-balance, and suggest that hypertension might be associated with reduced BMD in female EH. Less