Reactive Oxygen Species (ROS)-Dependent Hypertension in D2 Receptor Deficient Mice: 41
Reactive Oxygen Species (ROS)-Dependent Hypertension in D2 Receptor Deficient Mice: 41
复制标题
DOI：
--
复制
发表时间：
2006-10
期刊：
影响因子：
8.3
通讯作者：
I. Armando;Xiaoyan Wang;V. Villar;J. Jones;L. Asico;P. Jose
中科院分区：
文献类型：
--
作者：
I. Armando;Xiaoyan Wang;V. Villar;J. Jones;L. Asico;P. Jose
据报道，原发性高血压中多巴胺 D2 样受体功能发生改变。 D2 受体 (D2R) 基因外显子 6 的多态性与血压升高相关，Taq1 多态性与人类原发性高血压相关。我们之前已经表明，小鼠 D2R 的破坏 (D2-/-) 会导致高血压，这与醛固酮生成增加和高盐饮食抑制醛固酮缺陷有关。醛固酮已被证明可以增加 NADPH 氧化酶亚基的表达以及氧化应激。我们假设 D2-/ 中血压升高与 NADPH 氧化酶活性和 ROS 增加有关。我们通过 RT-PCR 测定了 D2-/ 及其野生型同窝仔鼠 D2 / 肾脏中 NADPH 氧化酶亚基 p22、p40、p47、p67、Rac1、Rac2、Nox1、Nox2 和 Nox4 的 mRNA 表达。Nox1、Nox2 和 Nox4 的 mRNA 表达分别增加了 30 3%、14 1 和 29 2%。 D2-/（p < 0.05 vs D2 /，每组 n 5）。两组中测试的其他亚基的 mRNA 表达相似。通过蛋白质印迹测定，D2-/小鼠肾脏中 Nox1、Nox2 和 Nox4 的蛋白表达分别增加了 45 8%、89 10 % 和 55 5%（与 D2/ 相比，p 0.05）。 8-异前列腺素的尿排泄量（77 15 vs 35 8 ng/mg 肌酐 [D2 / ]；p = 0.04，n 9）（氧化应激标志物）和肾脏 NADPH 氧化酶活性（121,300 15,310 vs 81,200 9,870 [D2 / ] LU/mg prot；p = 0.05；光泽精测定）在 D2-/小鼠中也有所增加。用血红素加氧酶 1 诱导剂血红素（50 mol，腹腔注射，24 小时）治疗，使麻醉 (Avertin) D2-/小鼠血压正常化（收缩压：媒介物：123 5；血红素：89 6 mmHg；p 0.05；n 5），但对 D2/小鼠没有影响（收缩压：媒介物：103 2；血红素： 100 1 毫米汞柱；n 5)。用夹竹桃麻素（一种 NADPH 氧化酶抑制剂）治疗（3 mg/k/天，通过微型渗透泵，10 天），也使 D2-/小鼠的血压正常化（收缩压：D2-/-，96 2；D2 / ，96 1 mmHg；每组 n 5）。我们的结果表明，D2R 参与 ROS 产生的调节，并表明通过直接和间接机制改变 D2R 功能可能导致 ROS 依赖性高血压。
Alterations in dopamine D2-like receptor function have been reported in essential hypertension. A polymorphism in exon 6 of the D2 receptor (D2R) gene is associated with elevated blood pressure and a Taq1 polymorphism is associated with human essential hypertension. We have previously shown that disruption of D2R in mice (D2-/-) results in high blood pressure that is associated with increased aldosterone production and defective aldosterone suppression by high salt diet. Aldosterone has been shown to increase the expression of NADPH oxidase subunits as well as oxidative stress. We hypothesized that the increased blood pressure in D2-/is related to increased NADPH oxidase activity and ROS. We determined the mRNA expression of the NADPH oxidase subunits p22, p40, p47, p67, Rac1, Rac2, Nox1, Nox2 and Nox4 by RT-PCR in kidneys of D2-/and their wild type littermates, D2 / .The mRNA expression of Nox1, Nox2 and Nox4 was increased 30 3, 14 1 and 29 2%, respectively in D2-/(p 0.05 vs D2 / , n 5 per group).The mRNA expression of the other subunits tested was similar in both groups. The protein expression of Nox1, Nox2 and Nox4, determined by western blot, was increased in kidneys of D2-/mice by 45 8, 89 10 and 55 5%, respectively (p 0.05 vs D2 / ). The urinary excretion of 8-isoprostane (77 15 vs 35 8 ng/mg creatinine [D2 / ]; p 0.04, n 9), a marker of oxidative stress, and renal NADPH oxidase activity (121,300 15,310 vs 81,200 9,870 [D2 / ] LU/mg prot; p 0.05; lucigenin assay) were also increased in D2-/mice. Treatment with hemin, an inducer of heme oxigenase-1 (50 mol, IP, for 24 h), normalized blood pressure in anesthetized (Avertin) D2-/mice (systolic: vehicle: 123 5; hemin: 89 6 mmHg; p 0.05; n 5) but had no effect in D2 / mice (systolic: vehicle: 103 2; hemin: 100 1 mmHg; n 5). Treatment with apocynin, a NADPH oxidase inhibitor (3 mg/k/day, via osmotic mini-pumps, 10 days), also normalized blood pressure in D2-/mice (systolic: D2-/-, 96 2; D2 / , 96 1 mmHg; n 5 per group). Our results show that the D2R is involved in the regulation of ROS production and suggest that by direct and indirect mechanisms altered D2R function may result in ROS-dependent hypertension.