Quantitative evaluation of the hydroxyl radical level after global brain ischemia by intracranial microdialysis under stereotaxis / 中华急诊医学杂志

ABSTRACT

Objective To compare the strength of oxidative stress from different concentrations of oxygen administered by the accumulation of hydroxyl radicals during early reperfusion after global brain ischemia.Methods Sixteen adult male Mongolian gerbils with microdialysis probes implanted in the hippocampal CA1 were divided randomly (random number)into two groups (n =8 in each).All gerbils of both groups were subjected to 10 min bilateral carotid artery occlusion (BCAO).Then the following intervention(a) immediate 30% O2 (near normoxia,NO group ) and (b ) immediate 100% O2 (hyperoxia,HO group).The accumulation of hydroxyl radicals (·OH)in hippocampus during reperfusion was estimated by measuring 2,3-dihydroxybenzoic acid (DHBA ) and 2,5-DHBA in microdialysis perfusate.Results Immediately after the onset of reperfusion,two groups showed markedly elevated DHBA,which returned to baseline gradually.Compared with the NO group,the HO group showed significantly higher peak DHBA and slower recovery.Conclusions Hydroxyl radical accumulation was more sensitive to inhalation of high concentration O2 during early reperfusion of global cerebral ischemia.