Shima H, Nishio I, Tsuda K, Yoshikawa H, Kimura K, Hano T, Masuyama Y
Department of Medicine, Wakayama Medical College, Japan.
Jpn J Med. 1989 Mar-Apr;28(2):165-9. doi: 10.2169/internalmedicine1962.28.165.
The present study was designed to assess if the release of Na-K ATPase inhibitor (NKAI) after salt-loading is related to sympathetic nervous system in essential hypertension. Thirteen patients with essential hypertension were studied during low-salt diet (2 g/day) and then high-salt diet (20 g/day) for each 7-days period. Mean blood pressure (MBP), body weight, Na:K ratio in red blood cell (R-Na/K), plasma norepinephrine (PNE) and NKAI were measured on the last day of each period. NKAI was determined by the degree of the inhibition of dog kidney Na-K ATPase activity by deproteinized plasma. Patients were classified as "salt-sensitive" (SS) or "nonsalt-sensitive" (NSS) group by the MBP responses to salt-loading. With the high-salt diet, SS group showed more body weight gain, greater increase in R-Na/K and NKAI (SS; 8.0 +/- 1.0%, NSS; 2.4 +/- 0.8%, P less than 0.01) than NSS group. PNE showed no changes in SS group and decreased in NSS group (P less than 0.05). The increase of MBP was highly correlated with the rise of NKAI (r = 0.76, P less than 0.01). Moreover, the increase of NKAI was also significantly correlated with the changes of PNE (r = 0.62, P less than 0.05). These results suggest that the greater increase in blood pressure by salt-loading in SS patients can be attributed to the increase of NKAI, which might regulate the sympathetic nervous system as a result of increased intracellular sodium.
本研究旨在评估盐负荷后钠钾ATP酶抑制剂（NKAI）的释放是否与原发性高血压患者的交感神经系统有关。13例原发性高血压患者在低盐饮食（2克/天）和随后的高盐饮食（20克/天）下各进行为期7天的研究。在每个阶段的最后一天测量平均血压（MBP）、体重、红细胞钠钾比（R-Na/K）、血浆去甲肾上腺素（PNE）和NKAI。NKAI通过脱蛋白血浆对犬肾钠钾ATP酶活性的抑制程度来测定。根据盐负荷后MBP的反应，将患者分为“盐敏感”（SS）或“非盐敏感”（NSS）组。高盐饮食时，SS组比NSS组体重增加更多，R-Na/K和NKAI升高幅度更大（SS组；8.0±1.0%，NSS组；2.4±0.8%，P＜0.01）。SS组PNE无变化，NSS组PNE下降（P＜0.05）。MBP的升高与NKAI的升高高度相关（r = 0.76，P＜0.01）。此外，NKAI的升高也与PNE的变化显著相关（r = 0.62，P＜0.05）。这些结果表明，SS患者盐负荷后血压升高幅度更大可归因于NKAI的增加，而NKAI可能因细胞内钠增加而调节交感神经系统。
