星状神经节阻滞对家兔脑缺血再灌注时氧自由基损伤的保护作用

目的：研究星状神经节阻滞（SGB）对脑缺血再灌注家兔脑组织超氧化物歧化酶（SOD）、丙二醛（MDA）以及含水率的影响．以探讨其对氧自由基损伤的作用机制。方法：选择SGB模型有效的家兔32只，随机分为4组（n=8）：假手术组（Sham组）、空白对照组（I／R组）、生理盐水对照组（NS组）和SGB组。SGB组再灌注开始时从兔颈部导管注人0．25％丁哌卡因0．5ml／h至再灌注12h时。NS组则注入NS0．5ml／h。I／R组不用任何药。各组于再灌注12h时断头取脑制成10％脑组织匀浆，检测SOD活性、MDA含量。结果：与Sham组比较，I／R组、NS组SOD活性均明显降低（P〈0．01），MDA含量明显增加（P〈0．01），脑组织含水率增加（P〈0.05），而I／R组与NS组比较差异无显著性意义；与I／R组、NS组比较，SGB组SOD活性显著升高而MDA含量明显降低（p〈0．01），脑组织含水率下降（P〈0．05）。结论：SGB可明显减轻脑水肿，提高脑组织内源性SOD生物活性，降低MDA含量，具有明显的抗氧自由基损伤作用，并因此而起到抗脑缺血再灌注损伤的作用。

Protective effects of satemte ganglion block against oxygen free radical damage in rabbits with cerebral ischemia-reperfusion

Objective:To observe the effects of satellate ganglion block(SGB) on SOD,MDA and water content of brain tissue in rabbits following cerebral ischemia-reperfusion(CIR) and to investigate the possibible mechanism of action of SGB against the oxygen free radical injury.Method:Thirty two healthy rabbits were randomly divided into 4 groups: sham group,blank control (I/R) group,NS group and SGB group. In SGB group right stellate ganglion was blocked at the beginning of reperfusion by 0.25% bupivacaine, at a rate of 0.5ml/h until 12h after reperfusion. In NS control group,0.5ml normal saline(NS) was used instead of bupivacaine at the same volume. Result:Compared with sham group,SOD activity significantly decreased(P<0.01) while MDA content and water content increased(P<0.05 or 0.01) in brain tissues in I/R and NS groups. There was no significant difference in each index between I/R and NS groups. However,SOD activity significantly increased(P<0.01) while MDA content and water content significantly decreased(P<0.05 or 0.01) in SGB group as compared to in I/R and NS groups,and there was no significant difference in each index between the right and left brain tissues in SGB group. Conclusion:SGB can effectively increase endogenic SOD activity and decrease MDA content in rabbits brain tissue and alleviate hydrocephalus. This study indicates that SGB can attenuate the oxygen free radical injury in brain tissue with CIR.