Influence of increased central venous pressure on baroreflex control of sympathetic activity in humans
Influence of increased central venous pressure on baroreflex control of sympathetic activity in humans
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DOI：
10.1152/ajpheart.00265.2004
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发表时间：
2004-10-01
影响因子：
4.8
通讯作者：
Joyner, MJ
中科院分区：
文献类型：
--
作者：
Charkoudian, N;Martin, EA;Joyner, MJ
容量扩张往往改善立位不耐受的症状，然而，这种增加的体积对血管交感神经活动的综合压力反射控制的影响是未知的。我们测试了中心静脉压（CVP）的急性增加是否会降低随后的肌肉交感神经活动（MSNA）对动脉压快速变化的反应性。我们在三种不同的条件下研究了健康人：对照组、急性头低位倾斜（HDT）和盐水输注（SAL）。在每种情况下，心率，动脉压，中心静脉压，腓MSNA在5分钟的休息，然后在动脉压的快速变化引起的硝普钠和苯肾上腺素（改良牛津技术）的顺序推注。MSNA和心率的综合压力反射控制的敏感性分别被评估为MSNA-舒张压和R-R间期-收缩压关系的线性部分的斜率。在SAL和HDT条件下，CVP均增加约2 mmHg。试验间静息心率和平均动脉压无差异。在SAL和HDT条件下，MSNA的压力反射控制敏感性分别为3.1 ± 0.6和3.3 ± 1.0，而在SAL和HDT条件下，MSNA的压力反射控制敏感性分别为5.0 ± 0.6单位·拍（-1）·mmHg（-1）（P
Volume expansion often ameliorates symptoms of orthostatic intolerance; however, the influence of this increased volume on integrated baroreflex control of vascular sympathetic activity is unknown. We tested whether acute increases in central venous pressure (CVP) diminished subsequent responsiveness of muscle sympathetic nerve activity (MSNA) to rapid changes in arterial pressure. We studied healthy humans under three separate conditions: control, acute 10 head-down tilt (HDT), and saline infusion (SAL). In each condition, heart rate, arterial pressure, CVP, and peroneal MSNA were measured during 5 min of rest and then during rapid changes in arterial pressure induced by sequential boluses of nitroprusside and phenylephrine ( modified Oxford technique). Sensitivities of integrated baroreflex control of MSNA and heart rate were assessed as the slopes of the linear portions of the MSNA-diastolic blood pressure and R-R interval-systolic pressure relations, respectively. CVP increased similar to2 mmHg in both SAL and HDT conditions. Resting heart rate and mean arterial pressure were not different among trials. Sensitivity of baroreflex control of MSNA was decreased in both SAL and HDT condition, respectively: similar to3.1+/-0.6 and similar to3.3+/-1.0 versus similar to5.0+/-0.6 units.beat(-1).mmHg(-1) (P