Díez J, Alonso A, Garciandía A, López R, Gómez-Alamillo C, Arrázola A, Fortuño A
Department of Internal Medicine, School of Medicine, University of Navarra, Pamplona, Spain.
Am J Hypertens. 1995 Feb;8(2):124-32. doi: 10.1016/0895-7061(94)00172-8.
The goal of this study was to investigate the activity of the Na+/H+ exchanger in erythrocytes of patients with essential hypertension and its relation with urinary Na+ excretion. The study was performed in cells from 27 untreated hypertensive patients and 30 normotensive controls with similar age and sex distribution. All subjects were studied after 4 days on a controlled Na+ diet (145 mmol/day). The activity of the Na+/H+ exchanger was determined by acidifying cell pH and measuring the initial rate of the net Na(+)-dependent H+ efflux. The activity of the Na+/H+ exchanger was higher in hypertensive patients than in controls (301 +/- 45 v 162 +/- 23 mmol/L cells/h, mean +/- SEM; P < .01). With the upper limit of the normotensive population as a cut-off point (385 mmol/L cells/h), a subgroup of 12 hypertensive patients had an abnormally high activity of Na+/H+ exchanger. Compared with controls and with patients with normal exchanger activity, patients with increased exchanger activity were characterized by lower net (P < .01) and fractional (P < .05) Na+ excretion. The accumulative Na+ balance was higher (P < .01) in hypertensive patients with increased activity of the exchanger (39.90 +/- 3.47 mmol) than in the remaining hypertensive patients (0.59 +/- 6.96 mmol) or in the normotensive population (-5.71 +/- 6.12 mmol). After analyzing the relationship of renin activity with Na+ excretion it was observed that renin activity was inappropriately low in 9 (75%) patients with increased exchanger, in 6 (40%) patients with normal exchanger, and in 6 (20%) normotensives, these differences being significant (P<.01).
本研究的目的是调查原发性高血压患者红细胞中Na+/H+交换体的活性及其与尿钠排泄的关系。该研究在27例未经治疗的高血压患者和30例年龄和性别分布相似的血压正常对照者的细胞中进行。所有受试者在接受4天的钠控制饮食（145 mmol/天）后进行研究。通过酸化细胞pH值并测量净Na(+)依赖性H+流出的初始速率来确定Na+/H+交换体的活性。高血压患者的Na+/H+交换体活性高于对照组（301±45对162±23 mmol/L细胞/小时，平均值±标准误；P<.01）。以血压正常人群的上限作为分界点（385 mmol/L细胞/小时），12例高血压患者的亚组Na+/H+交换体活性异常高。与对照组和交换体活性正常的患者相比，交换体活性增加的患者净钠排泄（P<.01）和钠排泄分数（P<.05）较低。交换体活性增加的高血压患者的累积钠平衡（39.90±3.47 mmol）高于其余高血压患者（0.59±6.96 mmol）或血压正常人群（-5.71±6.12 mmol）（P<.01）。在分析肾素活性与钠排泄的关系后，观察到交换体增加的9例（75%）患者、交换体正常的6例（40%）患者和6例（20%）血压正常者的肾素活性异常低，这些差异具有统计学意义（P<.01）。
