Interactions between CO2 chemoreflexes and arterial baroreflexes.
Interactions between CO2 chemoreflexes and arterial baroreflexes.
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CO2 化学反射和动脉压力反射之间的相互作用。
DOI：
10.1152/ajpheart.1998.274.6.h2177
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Eckberg,DL
中科院分区：
文献类型：
--
作者：
Henry,RA;Lu,IL;Beightol,LA;Eckberg,DL
我们研究了10个仰卧健康的年轻男性和女性之间的相互作用CO2化学反射和动脉压力反射。我们测量了迷走神经颈动脉压力感受器-心脏反射和稳态快速傅立叶变换R-R间期以及三种动脉压水平（硝普钠、生理盐水和苯肾上腺素输注）和三种潮气末CO2水平（3%、4%和5%，固定频率，大潮气量呼吸，CO2 + O2）下的光体积描记动脉压功率谱。我们的研究支持三个主要结论。首先，虽然低水平的CO2化学感受器刺激减少R-R间期和R-R间期变异性，统计模型表明，这种影响是间接的，而不是直接的，是由动脉压降低介导的。第二，在低碳酸血症期间R-R间期的减少反映了迷走神经介导的颈动脉压力反射反应在R-R间期轴上的简单移位，而不是压力反射增益、范围或操作点的变化。第三，CO2化学感受器刺激对动脉压的影响（以及衍生的R-R间期和R-R间期变异性）主要取决于基线动脉压水平：当压力低时，化学感受器效应较小，当动脉压高时，化学感受器效应较大。
We studied interactions between CO2chemoreflexes and arterial baroreflexes in 10 supine healthy young men and women. We measured vagal carotid baroreceptor-cardiac reflexes and steady-state fast Fourier transform R-R interval and photoplethysmographic arterial pressure power spectra at three arterial pressure levels (nitroprusside, saline, and phenylephrine infusions) and three end-tidal CO2levels (3, 4, and 5%, fixed-frequency, large-tidal-volume breathing, CO2plus O2). Our study supports three principal conclusions. First, although low levels of CO2chemoreceptor stimulation reduce R-R intervals and R-R interval variability, statistical modeling suggests that this effect is indirect rather than direct and is mediated by reductions of arterial pressure. Second, reductions of R-R intervals during hypocapnia reflect simple shifting of vagally mediated carotid baroreflex responses on the R-R interval axis rather than changes of baroreflex gain, range, or operational point. Third, the influence of CO2chemoreceptor stimulation on arterial pressure (and, derivatively, on R-R intervals and R-R interval variability) depends critically on baseline arterial pressure levels: chemoreceptor effects are smaller when pressure is low and larger when arterial pressure is high.