High Dietary Salt and Angiotensin II Chronically Increase Renal Sympathetic Nerve Activity A Direct Telemetric Study
High Dietary Salt and Angiotensin II Chronically Increase Renal Sympathetic Nerve Activity A Direct Telemetric Study
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DOI：
10.1161/hypertensionaha.111.180885
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发表时间：
2012-03-01
期刊：
影响因子：
8.3
通讯作者：
Barrett, Carolyn J.
中科院分区：
文献类型：
--
作者：
Guild, Sarah-Jane;McBryde, Fiona D.;Barrett, Carolyn J.
长期以来，交感神经系统的过度活动与高血压对血管紧张素II（Ang II）水平升高的反应有关。虽然最近的研究表明，高盐饮食可能会改变心血管反应的血管紧张素II，直接证据表明慢性激活交感神经活动缺乏。本研究的目的是确定在高盐摄入的背景下，低剂量的Ang II是否会导致肾交感神经活动（RSNA）的慢性增加。通过遥测记录动脉压和RSNA。研究了两组家兔：一组饮用0.9%NaCl溶液并接受Ang II（20 ng/kg/min，持续21天，盐+ Ang），另一组始终饮用自来水，不输注Ang II（对照组）。在盐+ Ang组中，平均动脉压在第一周内增加，并在第21天保持升高18.5 +/- 4.1 mm Hg。RSNA在第7天在组间没有显著差异，但在第21天在盐+ Ang组中显著升高（13.5 +/-3.2%相比于对照组中的6.8 +/-0.8%; P < 0.05）。RSNA的压力感受性反射控制在第21天出现明显偏移，但在第7天没有变化，并且压力感受性反射反应表明当动脉压升高时RSNA不能被完全抑制。对照组的平均动脉压或RSNA变量均未观察到变化。我们的研究结果支持这一假设，即升高的血管紧张素II水平，结合高盐饮食，有能力长期增加RSNA，因此，可能有助于维持高血压。（高血压。2012; 59：614-620.）。在线补充资料
Overactivity of the sympathetic nervous system has long been implicated in the hypertensive response to elevated angiotensin II (Ang II) levels. Although recent studies suggest that high dietary salt may alter cardiovascular responses to Ang II, direct evidence demonstrating chronic activation of sympathetic nerve activity is lacking. The objective of this study was to determine whether a low dose of Ang II, on a background of high salt intake, would result in a chronic increase in renal sympathetic nerve activity (RSNA). Arterial pressure and RSNA were recorded via telemetry. Two groups of rabbits were studied: 1 group drank a 0.9% NaCl solution and received Ang II (20 ng/kg per minute for 21 days, Salt + Ang), and the other drank tap water throughout and was not infused with Ang II (Control). In the Salt + Ang group, mean arterial pressure increased over the first week and remain elevated by 18.5 +/- 4.1 mm Hg at day 21. RSNA was not significantly different between groups on day 7 but was significantly elevated in the Salt + Ang group on day 21 (13.5 +/- 3.2% compared with 6.8 +/- 0.8% in the Control group; P < 0.05). Baroreflex control of RSNA showed a rightward shift on day 21, but not day 7, and baroreflex responses indicated that RSNA could not be completely suppressed when arterial pressure was increased. No changes were observed in either mean arterial pressure or RSNA variables in the Control group. Our results support the hypothesis that elevated Ang II levels, in conjunction with a high salt diet, have the ability to chronically increase RSNA and, thus, potentially contribute to the maintenance of hypertension. (Hypertension. 2012; 59: 614-620.). Online Data Supplement