Modulation of control of muscle sympathetic nerve activity during orthostatic stress in humans
Modulation of control of muscle sympathetic nerve activity during orthostatic stress in humans
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DOI：
10.1152/ajpheart.00215.2004
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发表时间：
2004-11-01
影响因子：
4.8
通讯作者：
Nishiyasu, T
中科院分区：
文献类型：
--
作者：
Ichinose, M;Saito, M;Nishiyasu, T
我们测试了这样一种假设，即立位应激将调节动脉压力感受器反射(ABR)介导的肌交感神经活动(MSNA)节拍控制。在12名健康受试者中，通过分析仰卧位和两个下体负压水平(下体负压分别为-15和-35 mm Hg)时舒张压(DAP)和舒张压(MSNA)的逐拍自发变化之间的关系，评价ABR对MSNA(爆发发生率、爆发强度和总活动度)的控制。在-15毫米汞柱下体负压时，猝发发生率(每100次心跳的猝发次数)与DAP之间的关系较CON时有所上升，但在-35毫米汞柱下体负压时的进一步变化仅是微乎其微的。爆裂强度与DAP的关系在-15 mm HgLBNP(vs.CON)时向上移动，在-35 mm HgLBNP时进一步上移。在-15 mm HgLBNP时，总活性与DAP的关系比CON时的关系上移，在-35 mm HgLBNP时进一步上移。这些结果表明，ABR对MSNA的控制是在立位应激过程中调节的，并且在轻度(非低血压)和中等(低血压)水平的立位应激中，这种调节是不同的。
We tested the hypothesis that orthostatic stress would modulate the arterial baroreflex (ABR)mediated beat-by-beat control of muscle sympathetic nerve activity (MSNA) in humans. In 12 healthy subjects, ABR control of MSNA ( burst incidence, burst strength, and total activity) was evaluated by analysis of the relation between beat-by-beat spontaneous variations in diastolic blood pressure (DAP) and MSNA during supine rest ( CON) and at two levels of lower body negative pressure ( LBNP: - 15 and - 35 mmHg). At - 15 mmHg LBNP, the relation between burst incidence ( bursts per 100 heartbeats) and DAP showed an upward shift from that observed during CON, but the further shift seen at - 35 mmHg LBNP was only marginal. The relation between burst strength and DAP was shifted upward at - 15 mmHg LBNP ( vs. CON) and further shifted upward at - 35 mmHg LBNP. At - 15 mmHg LBNP, the relation between total activity and DAP was shifted upward from that obtained during CON and further shifted upward at - 35 mmHg LBNP. These results suggest that ABR control of MSNA is modulated during orthostatic stress and that the modulation is different between a mild (nonhypotensive) and a moderate ( hypotensive) level of orthostatic stress.