目的观察单次高压氧(HBO)治疗9 h 对永久性大脑中动脉阻塞(MCAO)大鼠细胞色素C和caspase-3 水平的影响。方法48 只Sprague-Dawley 大鼠制作永久性MCAO模型，分为对照组(n=24)和高压氧组(n=24)，高压氧组大鼠于造模成功后3 h 予单次高压氧治疗9 h，压力0.2 MPa。于造模成功后3 h、13 h、24 h 行大鼠Garcia 神经功能评分，于造模成功后13 h、24 h TUNEL法检测大鼠脑组织细胞凋亡数，ELISA 法检测缺血半暗带脑组织细胞色素C及活性caspase-3 水平。结果两组大鼠造模成功后13h、24 h 神经功能均有明显改善，两组间无显著性差异(t<2.07, P>0.05)。两组造模成功后13 h、24 h 均见凋亡细胞，高压氧组明显少于对照组(t>6.57, P<0.01)。高压氧组细胞色素C和caspase-3 的水平在造模成功后24 h 低于对照组(t>2.41, P<0.05)。结论大剂量高压氧超早期治疗可降低脑缺血后细胞色素C和caspase-3 水平，减少细胞凋亡，可能是高压氧治疗脑梗死的机制之一。

Objective To observe the effect of single intensive hyperbaric oxygenation (HBO) on cytochrome C and caspase-3 in rats after permanent middle cerebral artery occlusion (MCAO) very early. Methods Forty-eight male Sprague-Dawley rats were subjected to permanent MCAO model using the intraluminal suture method, and were divided into control group (n=24) and HBO group (n=24). The HBO group stayed in the hyperbaric cabin with a pressure of 0.2 MPa for 9 hours 3 hours after MCAO. They were measured with Garcia scores 3 hours, 13 hours and 24 hours after MCAO. Apoptosis cells of ischemic penumbra tissue were investigated with TUNEL 13 hours and 24 hours after MCAO, while the level of cytochrome C and caspase-3 were measured with ELISA. Results The Garcia scores increased 13 hours and 24 hours after MCAO in both groups, but there was no significant difference between groups (t<2.07, P>0.05). The apoptosis cells were found in both groups 13 hours and 24 hours after MCAO, and less in the HBO group than in the control group (t>6.57, P<0.01). The levels of cytochrome C and caspase-3 were less in the HBO group than in the control group 24 hours after MCAO (t>2.41, P<0.05). Conclusion A single intensive HBO in very early stage may improve neurological function after cerebral ischemia in rats, which may associate with the inhibition of cytochrome C and caspase-3 to reduce cell apoptosis.