Abstract:

Objective    To investigate the effect of normobaric hyperoxia on blood brain barrier impairment following cerebral ischemiareperfusion in rats, and explore the mechanism．Methods    30 normal male SD rats were randomly divided into 2 groups: ① cerebral ischemia-reperfusion control group ( n=15 )， and ② normobaric hyperoxia treatment group ( n= 5 ). Cerebral ischemia-reperfusion rat models were established by the thread ligation of right middle cerebral artery . At 24 hrs after the reperfusion following 90min ischemia, TTC staining, Evans blue dye extravasation and Gelatin zymography were applied to quantify infarction volume, blood-brain barrier impairment and the activity of MMP-9, respectively. Neurological deficit scores were also evaluated. Results    Compared with the control group, normobaric hyperoxia treatment significantly decreased Evans blue dye extravasation, the activity of MMP-9 and infarct volume (P﹤0.01) at 24 hrs after the reperfusion. Correspondingly, neurological functions were improved. Conclusions    Nnormobaric hyperoxia treatment during the period of focal cerebral ischemia demonstrates the protective effect on blood-brain barrier impairment in the rat model of cerebral ischemia-reperfusion, and the mechanism may be attributed to the suppression of  MMP-9. 

Key words: Reperfusion injury; Hypoxia-ischemia，brain ; Blood-brain barrier；Gelatinase B；Rats