Hypoxic cutaneous vasodilation is sustained during brief cold stress and is not affected by changes in CO2.
Hypoxic cutaneous vasodilation is sustained during brief cold stress and is not affected by changes in CO2.
复制标题
缺氧的皮肤血管舒张在短暂的冷应激期间持续存在，并且不受二氧化碳变化的影响。
DOI：
10.1152/japplphysiol.01221.2009
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Halliwill,JohnR
中科院分区：
文献类型：
--
作者：
Simmons,GrantH;Fieger,SarahM;Minson,ChristopherT;Halliwill,JohnR
Hypoxia decreases core body temperature in animals and humans during cold exposure. In addition, hypoxia increases skin blood flow in thermoneutral conditions, but the impact of hypoxic vasodilation on vasoconstriction during cold exposure is unknown. In this study, skin blood flow was assessed using laser-Doppler flowmetry, and cutaneous vascular conductance (CVC) was calculated as red blood cell flux/mean arterial pressure and normalized to baseline (n= 7). Subjects were exposed to four different conditions in the steady state (normoxia and poikilocapnic, isocapnic, and hypercapnic hypoxia) and were cooled for 10 min using a water-perfused suit in each condition. CVC increased during all three hypoxic exposures (allP< 0.05 vs. baseline), and the magnitude of these steady-state responses was not affected by changes in end-tidal CO2levels. During poikilocapnic and hypercapnic hypoxia, cold exposure reduced CVC to the same levels observed during normoxic cooling (P> 0.05 vs. normoxia), whereas CVC remained elevated throughout cold exposure during isocapnic hypoxia (P< 0.05 vs. normoxia). The magnitude of vasoconstriction during cold stress was similar in all conditions (P> 0.05). Thus the magnitude of cutaneous vasodilation during steady-state hypoxia is not affected by CO2responses. In addition, the magnitude of reflex vasoconstriction is not altered by hypoxia, such that the upward shift in skin blood flow (hypoxic vasodilation) is maintained during whole body cooling.
