Effects of heat stress on baroreflex function in humans.
Effects of heat stress on baroreflex function in humans.
复制标题
热应激对人类压力反射功能的影响。
DOI：
10.1046/j.1365-201x.2003.01076.x
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Wilson,ThadE
中科院分区：
文献类型：
--
作者：
Crandall,CraigG;Cui,Jian;Wilson,ThadE
导语：热应激显著降低人体的立位耐力。导致这种反应的机制(S)尚不清楚。这篇综述文章的目的是提供关于热应激个体立位耐力降低是由于热应激导致压力反射功能改变的假设的数据。方法：在常温和热应激条件下，通过药理学和非药理学方法评估压力感受性反射反应。结果：总体上，全身加热不会改变压力反射敏感性，压力反射敏感性定义为压力反射曲线围绕操作点的线性部分的增益。然而，全身加热使压力感受性反射曲线向心率和肌肉交感神经活动的方向移动。最后，热应激损害了血管收缩对外源性肾上腺素能激动剂的反应。结论：目前的数据不支持这样的假设，即人类与热应激相关的立位耐受性降低是由于压力感受性反射反应受损。这一现象可能部分是由于热应激降低血管收缩反应性所致。
Introduction:Heat stress significantly reduces orthostatic tolerance in humans. The mechanism(s) causing this response remain unknown. The purpose of this review article is to present data pertaining to the hypothesis that reduced orthostatic tolerance in heat stressed individuals is a result of heat stress induced alterations in baroflex function.Methods:In both normothermic and heat stressed conditions baroreflex responsiveness was assessed via pharmacological and non‐pharmacological methods. In addition, the effects of heat stress on post‐synaptic vasoconstrictor responsiveness were assessed.Results:Generally, whole body heating did not alter baroreflex sensitivity defined as the gain of the linear portion of the baroreflex curve around the operating point. However, whole body heating shifted the baroreflex curve to the prevailing (i.e. elevated) heart rate and muscle sympathetic nerve activity. Finally, the heat stress impaired vasoconstrictor responses to exogenous administration of adrenergic agonists.Conclusion:Current data do not support the hypothesis that reduced orthostatic tolerance associated with heat stress in humans is due to impaired baroreflex responsiveness. This phenomenon may be partially due to the effects of heat stress on reducing vasoconstrictor responsiveness.