Endogenous angiotensin affects responses to stimulation of baroreceptor afferent nerves.
Endogenous angiotensin affects responses to stimulation of baroreceptor afferent nerves.
复制标题
内源性血管紧张素影响压力感受器传入神经刺激的反应。
DOI：
10.1097/00004872-200308000-00019
复制
发表时间：
2003
影响因子：
4.9
通讯作者：
Jones,SusanY
中科院分区：
文献类型：
--
作者：
DiBona,GeraldF;Jones,SusanY
目的研究内源性血管紧张素II(AngⅡ)对标准化刺激传入神经传入动脉和心脏压力反射中枢的反应的影响，采用不同的膳食钠摄入量改变内源性Ang II的活性。血管紧张素Ⅱ1型受体拮抗剂坎地沙坦用于评估血管紧张素Ⅱ刺激血管紧张素Ⅱ1型受体所观察到的效应的依赖性。采用电刺激动脉和心脏压力感受性传入神经的方法，为动脉和心脏压力反射的中枢提供标准化的输入。方法在低、正常和高钠摄入量的平衡状态下，测定麻醉大鼠的动脉压、心率和肾交感神经活动对电刺激迷走神经和降压神经的反应。与正常膳食钠摄入大鼠相比，低膳食钠摄入大鼠血浆肾素活性升高，高膳食钠摄入大鼠血浆肾素活性降低。迷走神经刺激时，三种膳食钠摄入量组的心率、动脉压和肾交感神经活动反应相似。在主动脉降压神经刺激期间，三个饮食钠摄入量组的心率和动脉压反应都是相似的。但在4、8和16赫兹时，低钠组的肾交感神经活动反应显著高于正常组和高钠组。低钠饮食大鼠给予坎地沙坦对迷走神经和降主动脉神经刺激的心率和动脉压无影响，但增加了肾脏交感神经抑制反应的幅度。结论低钠饮食大鼠内源性血管紧张素II的增加减弱了标准化迷走神经和主动脉降压神经刺激分别激活心脏和窦主动脉压力反射所引起的肾脏交感神经抑制反应。
ObjectiveTo study effects of endogenous angiotensin II on responses to standardized stimulation of afferent neural input into the central portion of the arterial and cardiac baroreflexes.DesignDifferent dietary sodium intakes were used to physiologically alter endogenous angiotensin II activity. Candesartan, an angiotensin II type 1 receptor antagonist, was used to assess dependency of observed effects on angiotensin II stimulation of angiotensin II type 1 receptors. Electrical stimulation of arterial and cardiac baroreflex afferent nerves was used to provide a standardized input to the central portion of the arterial and cardiac baroreflexes.MethodsIn anesthetized rats in balance on low, normal and high dietary sodium intake, arterial pressure, heart rate and renal sympathetic nerve activity responses to electrical stimulation of vagus and aortic depressor nerves were determined. Compared with plasma renin activity values in normal dietary sodium intake rats, those from low dietary sodium intake rats were higher and those from high dietary sodium intake rats were lower. During vagus nerve stimulation, the heart rate, arterial pressure and renal sympathetic nerve activity responses were similar in all three dietary sodium intake groups. During aortic depressor nerve stimulation, the heart rate and arterial pressure responses were similar in all three dietary sodium intake groups. However, the renal sympathetic nerve activity response was significantly greater in the low sodium group than in the normal and high sodium group at 4, 8 and 16 Hz. Candesartan administered to low dietary sodium intake rats had no effect on the heart rate and arterial pressure responses to either vagus or aortic depressor nerve stimulation but increased the magnitude of the renal sympathoinhibitory responses.ConclusionsIncreased endogenous angiotensin II in rats on a low dietary sodium intake attenuates the renal sympathoinhibitory response to activation of the cardiac and sinoaortic baroreflexes by standardized vagus and aortic depressor nerve stimulation, respectively.