Normobaric hyperoxia improves cerebral blood flow and oxygenation, and inhibits peri-infarct depolarizations in experimental focal ischaemia
Normobaric hyperoxia improves cerebral blood flow and oxygenation, and inhibits peri-infarct depolarizations in experimental focal ischaemia
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DOI：
10.1093/brain/awm071
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发表时间：
2007-06-01
期刊：
影响因子：
14.5
通讯作者：
Ayata, Cenk
中科院分区：
文献类型：
--
作者：
Shin, Hwa Kyoung;Dunn, Andrew K.;Ayata, Cenk
Normobaric hyperoxia is under investigation as a treatment for acute ischaemic stroke. In experimental models, normobaric hyperoxia reduces cerebral ischaemic injury and improves functional outcome. The mechanisms of neuroprotection are still debated because, (i) inhalation of 100% O-2 does not significantly increase total blood O-2 content; (ii) it is not known whether normobaric hyperoxia increases O-2 delivery to the severely ischaemic cortex because of its short diffusion distance; and (iii) hyperoxia may reduce collateral cerebral blood flow (CBF) to ischaemic penumbra because it can cause vasoconstriction. We addressed these issues using real-time two-dimensional multispectral reflectance imaging and laser speckle flowmetry to simultaneously and non-invasively determine the impact of normobaric hyperoxia on CBF and oxygenation in ischaemic cortex. Ischaemia was induced by distal middle cerebral artery occlusion (dMCAO) in normoxic (30% inhaled O-2, arterial pO(2) 134 +/- 9 mm Hg), or hyperoxic mice (100% inhaled 02 starting 15 min after dMCAO, arterial pO(2) 312 +/- 10 mm Hg). Post-ischaemic normobaric hyperoxia caused an immediate and progressive increase in oxyhaemoglobin (oxyHb) concentration, nearly doubling it in ischaernic core within 60 min. In addition, hyperoxia improved CBF so that the area of cortex with
