Abnormal expression of ENaC and SGK1 mRNA induced by dietary sodium in Dahl salt-sensitively hypertensive rats
Abnormal expression of ENaC and SGK1 mRNA induced by dietary sodium in Dahl salt-sensitively hypertensive rats
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DOI：
10.1016/j.cellbi.2007.03.036
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发表时间：
2007-10-01
影响因子：
3.9
通讯作者：
Marunaka, Yoshinori
中科院分区：
文献类型：
--
作者：
Aoi, Wataru;Niisato, Naomi;Marunaka, Yoshinori
上皮性钠通道(ENaC)在控制肾脏对钠的重吸收、维持正常血压方面起着至关重要的作用。我们曾报道Dahl盐敏感(DS)大鼠肾脏ENaC mRNA的表达受到醛固酮的异常调节，但目前尚不清楚膳食钠是否影响DS大鼠肾脏ENaC、血清和糖皮质激素调节的激酶1(SGK1)的表达，SGK1在DS大鼠的ENaC激活中起重要作用。在本研究中，我们研究了饮食钠是否异常影响DS大鼠ENaC和SGK1mRNA的表达。将8周龄DS和Dahl耐盐(DR)大鼠分为3组：(1)低钠组(0.005%氯化钠)，(2)正常钠组(0.3%氯化钠)，(3)高钠饮食(8%氯化钠)。高钠饮食4周后，DS大鼠的收缩压升高，而其他各组大鼠的收缩压无明显变化。与DR大鼠相比，DS大鼠高钠饮食后α-ENaC基因表达异常增加，而与DR大鼠相似，DS大鼠低钠饮食后α-ENaC基因表达正常增加。与DR大鼠不同，高钠饮食可使DS大鼠的β-和γ-ENaC基因表达异常增加。高钠饮食可使DS大鼠SGK1mRNA表达增加，而DR大鼠SGK1mRNA表达降低。这些观察结果表明，盐敏感性高血压大鼠ENaC和SGK1基因的表达受到膳食钠的异常调节，这种异常表达可能是引起盐敏感性高血压的因素之一。(C)2007年国际细胞生物学联合会。爱思唯尔有限公司出版。保留所有权利。
Epithelial sodium channel (ENaC) plays a crucial role in controlling sodium reabsorption in the kidney keeping the normal blood pressure. We previously reported that the expression of ENaC mRNA in the kidney of Dahl salt-sensitive (DS) rats was abnormally regulated by aldosterone, however it is unknown if dietary sodium affects the expression of ENaC and serum and glucocorticoid-regulated kinase 1 (SGK1), which plays an important role in ENaC activation, in DS rats. In the present study, we investigated whether dietary sodium abnormally affects the expression of ENaC and SGK1 mRNA in DS rats. DS and Dahl salt-resistant (DR) rats (8 weeks old) were divided into three different groups, respectively: (1) low sodium diet (0.005% NaCl), (2) normal sodium diet (0.3% NaCl), and (3) high sodium diet (8% NaCl). The high sodium diet for 4 weeks in DS rats elevated the systolic blood pressure, but did not in any other groups. The expression of alpha-ENaC mRNA in DS rats was abnormally increased by high sodium diet in contrast to DR rats, while it was normally increased by low sodium diet in DS rats similar to DR rats. The expression of beta- and gamma-ENaC mRNA in DS rats was also abnormally increased by high sodium diet unlike DR rats. The expression of SGK1 mRNA was elevated by high sodium diet in DS rats, but it was decreased in DR rats. These observations indicate that the expression of ENaC and SGK1 mRNA is abnormally regulated by dietary sodium in salt-sensitively hypertensive rats, and that this abnormal expression would be one of the factors causing salt-sensitive hypertension. (c) 2007 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.