Abstract: Objective To investigate the effect of immediate hyperbaric oxygen on focal cerebral ischemia of rats. Methods Sprague-Dawly rats were randomly divided into control group (n=9), hyperbaric air group (n=9), hyperbaric oxygen group (n=9) and sham group (n=5). The middle cerebral arteries were occluded in the former 3 groups, while the hyperbaric air group and the hyperbaric oxygen group operated in the hyperbaric chamber, and the hyperbaric oxygen group accepted hyperbaric oxygen immediately after operation. All the rats were sacrificed 6 hours after operation and the percentage of volume of infarction in the brain slices was calculated. Results The percentage of infarction decreased in both hyperbaric oxygen group and hyperbaric air group compared with the control group (P<0.001), and decreased more in the hyperbaric oxygen therapy than in the hyperbaric air group (P<0.001). Conclusion Immediate hyperbaric oxygen therapy can reduce infarct size in rats after focal cerebral ischemia.

Key words: cerebral ischemia, immediate hyperbaric oxygen, infarct size, rats