Modulation of arterial baroreflex dynamic response during mild orthostatic stress in humans
Modulation of arterial baroreflex dynamic response during mild orthostatic stress in humans
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DOI：
10.1113/jphysiol.2003.057133
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发表时间：
2004-05-15
影响因子：
5.5
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：在人类中，颈动脉压力感受性反射的动态反应(通过检测颈动脉压力感受性反射引起的肌肉交感神经活动(MSNA)、平均动脉压(MAP)和心率(HR)变化的时间进程来评估)会在轻度立位应激期间改变，以限制立位性低血压。对12例健康受试者(男10例，女2例)，在静息和下体负压(-15 mm Hg)状态下，用颈动脉压力(NP)(50 Mm Hg)和颈吸力(NS)(-60 mm Hg)的5-S周期评价颈动脉压力感受器反射功能。在下体负压时(与CON相比)，(A)NP引起的MSNA和MAP的增加更大，(B)NS引起的MSNA抑制的时间更短，(C)NS引起的MAP下降的峰值虽然在幅度上没有什么不同，但在NS后发生得更早，恢复到初始水平更快，以及(D)对NP和NS的HR反应更大。这些结果表明，在轻度立位应激期间，颈动脉-压力感受器反射的动态反应受到调节，有助于维持血压并限制立位性低血压。
We tested the hypothesis that in humans, carotid-baroreflex dynamic responses (evaluated by examining the time course of the carotid-baroreflex-induced alterations in muscle sympathetic nerve activity (MSNA), mean arterial blood pressure (MAP) and heart rate (HR)) would be altered during mild orthostatic stress in ways that serve to limit orthostatic hypotension. In 12 healthy subjects (10 male, 2 female), 5-s periods of neck pressure (NP) (50 mmHg) and neck suction (NS) (- 60 mmHg) were used to evaluate carotid baroreflex function at rest (CON) and during lower body negative pressure (LBNP) (- 15 mmHg). During LBNP (as compared with CON) (a) the augmentations in MSNA and MAP elicited by NP were greater, (b) the NS-induced period of MSNA suppression was, if anything, shorter, (c) the peak decrement in MAP elicited by NS, although not different in amplitude, occurred earlier and recovered to its initial level more quickly after NS, and (d) the HR responses to NP and NS were greater. These results suggest that during mild orthostatic stress, carotid-baroreflex dynamic responses are modulated in ways that should help maintain blood pressure and limit orthostatic hypotension.