Abstract: ObjectiveTo investigate the effect of hyperbric oxygen (HBO) on infarct volume and relevant mechanism after permanent focal cerebral ischemia in adult rats.MethodsRat model of focal cerebral ischemia induced by intraluminal filament occlusion of middle cerebral artery (MCA) was used. HBO(2.0 ATA) was applied to HBO group. Infarct volume, matrix metalloproteinase 2 (MMP-2) and MMP-9 were detected at 6h, 24h, 48h, 72h,120h and 10d after ischemia.ResultsThe infarct volume obviously decreased at 120h and 10d and expression of MMP-9 lowered at 48—120h in HBO groups. There was no significant change in MMP-2.Conclusion HBO can reduce infarct volume after cerebral ischemia, which may be related to downregulation of MMP-9 levels.

Key words: hyperbric oxygen (HBO), focal cerebral ischemia, matrix metalloproteinase (MMP)