高压氧对大鼠局灶性脑缺血/再灌注脑线粒体能量代谢的影响

Effects of hyperbaric oxygen on cerebral mitochondrial energy metabolism after brain ischemia/reperfusion in rats

目的 :探讨高压氧 (HBO)对大鼠局灶性脑缺血 /再灌注 (IR)后脑线粒体三磷酸腺苷 (ATP)生成量及质子转移性三磷酸腺苷合成酶 (F0 F1-ATPase)活性的影响。方法 :用线栓法阻断大脑中动脉 (MCA)的大鼠局灶性IR模型。用Clark的Ficoll密度梯度法分离纯化的线粒体 ,用生化方法测定线粒体F0 F1-ATPase活性 ,用高效液相色谱技术 (HPLC)测定脑线粒体腺苷酸含量。Wistar大鼠 30只 ,随机分为 3组 :正常对照组 (normal) 6只 ,缺血 /再灌注组 (IR组 ) 12只 ,高压氧治疗组 12只。IR组、HBO组缺血时间均为 2h ,两组均等分为再灌注 2h、2 4h(I2hR2h、I2hR2 4h、HBO -I2hR2h、HBO -I2hR2 4h2组 ;IR组用 1个大气压 (ATA)O2 治疗 ;HBO组用 2 .5ATAO2 治疗。结果 :HBO治疗后ATP生成量及F0 F1-ATPase活性增加 ;IR组ATP生成量、F0 F1-ATPase活性明显低于HBO组。结论 :HBO可能是通过恢复F0 F1-ATPase的活性 ,增加ATP合成而改善脑线粒体有氧代谢 ,减轻缺血性脑损害 。

Objective:To study the effects of hyperbaric oxygen(HBO) on the levels of cerebral mitochondrial adenosine triphosphate (ATP) and proton-translocating ATP synthases(F 0F 1-ATPase) after brain ischemia/reperfusion (IR) in rats.Methods:Thirty Wistar rats were randomly divided into 3 groups:normal contorl group (n=6) ,IR group (n=12) and HBO group ( n=12 ).IR was performed by ligation of the middle cerebral artery for 2 hours (hs) and then reperfusion in both the IR and HBO groups.The IR group was subdivided into group I 2h R 2h and group I 2h R 24h .The HBO group was subdivided into group HBO-I 2h R 2h and group HBO-I 2h R 24h .The IR group was treated by 2.5 ATAO 2.The HBO group was treated by 2.5 ATA O 2.The pure mitochondria was separated by Clak's Ficoll density gradient method.The activity of F 0F 1-ATPase was determined by biochemical technigue and the level of cerebral ATP by high-performance liquid chromatography (HPLC).Results:The level of ATP and the activity of F 0F 1-ATPase increased after HBO treatment.In the IR group,the level of ATP and the activity of F 0F 1-ATPase were significantly lower than those of the HBO group( P <0.01).Conclusion:HBO improves mitochondrial oxygen metabolism,alleviates cerebral ischemic injury and protects brain tissues by means of recovering the activity of F 0F 1-ATPase and increasing the synthesis of ATP.