Cardiovascular neural regulation during and after prolonged high altitude exposure.
Cardiovascular neural regulation during and after prolonged high altitude exposure.
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长期高海拔暴露期间和之后的心血管神经调节。
DOI：
10.1093/oxfordjournals.eurheartj.a060415
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发表时间：
1994
影响因子：
39.3
通讯作者：
G. Buja
中科院分区：
文献类型：
--
作者：
A. Ponchia;D. Noventa;M. Bertaglia;R. Carretta;M. Zaccaria;G. Miraglia;P. Pascotto;G. Buja
8名来自喜马拉雅探险队的年轻健康男性受试者在出发前、进入高海拔(5000米)后1周和4周以及返回海平面后进行24小时动态心电图监测。在高海拔地区，低频和高频(LF、HF)没有昼夜倒数变化，24 h内LF/HF比值没有明显降低，而且相邻R-R间期相差超过50ms的比例(PNN50)显著减少，并在返回海平面后保持较低水平。尿儿茶酚胺在高海拔地区增加，但只有去甲肾上腺素在暴露1周后显著增加。回到海平面后，与考察前相比，血小板上[α]2-肾上腺素能受体的密度显著下降，但亲和力没有显著下降。在高海拔地区，交感神经活动增强表现为尿去甲肾上腺素升高和频谱成分昼夜节律的丧失。HF和pNN50同时降低表明迷走神经张力降低。交感神经活性持续增强可以解释长期高原暴露后肾上腺素能受体下调的原因。
Eight young healthy male subjects, members of a Himalayan expedition, underwent 24 h Holter monitoring before departure, after 1 and 4 weeks at high altitude (5000 m) and after return to sea level. At high altitude, the circadian reciprocal changes in low and high frequency (LF, HF) were absent, with no significant reduction in the LF to HF ratio over the 24 h; moreover, the proportion of adjacent R-R intervals that differed by more than 50 ms (pNN50) decreased significantly and remained lower after return to sea level. Urine catecholamines increased at high altitude, but only norepinephrine, after 1 week of exposure, rose significantly. Upon return to sea level the density, but not the affinity, of [alpha]2-adrenergic receptors on platelets decreased significantly compared to pre-expedition values. At high altitude increased sympathetic activity was indicated by elevation of urine norepinephrine and by the loss of circadian rhythm in spectral components. The simultaneous reduction of HF and pNN50 demonstrated decreased vagal tone. The persistence of increased sympathetic activity could explain the downregulation of adrenergic receptors after prolonged high altitude exposure.