不同脑温状态银杏叶提取物对大鼠缺血脑组织氧自由基的影响

Effects of Ginkgo biloba extract in different cerebral temperature on the oxygen free radical concentration in rat focal cerebral ischemia

目的探讨不同脑温状态下银杏叶提取物(GBE)对大鼠缺血脑组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)及丙二醛(MDA)的影响。方法建立大鼠大脑中动脉缺血再灌注模型,诱导目标脑温,测定各组缺血脑组织SOD、GSH-Px和MDA含量。结果①与常温假手术组比较,常温脑缺血对照组及常温银杏叶组SOD和GSH-Px水平显著降低(均P<0.001),MDA水平显著增高(均P<0.001)。②与常温脑缺血对照组比较,常温银杏叶组及亚低温脑缺血组SOD和GSH-Px水平显著增高(均P<0.001),MDA水平显著降低(均P<0.001)。③与常温银杏叶组比较,轻度高温银杏叶组SOD和GSH-Px水平显著降低(均P<0.001),MDA水平显著增高(P<0.001);亚低温脑缺血组及亚低温银杏叶组SOD和GSH-Px水平显著增高(均P<0.001),MDA水平显著降低(P<0.001)。④与亚低温脑缺血组比较,亚低温银杏叶组SOD、GSH-Px及MDA水平差异均无显著性(均P>0.05)。结论①脑缺血/再灌注过程中,GBE修复缺血脑组织抗氧化酶/氧自由基失衡的作用受不同脑温的影响。常温状态下,GBE有修复抗氧化酶/氧自由基失衡的作用,从而对脑缺血有保护作用;轻度高温状态下,GBE无此作用;亚低温状态下,GBE的作用增强,从而增强对脑缺血的保护作用。②亚低温和GBE联合干预,修复抗氧化酶/氧自由基失衡,增强对脑缺血的保护作用,可能不是单一因素作用的结果,而是亚低温作用为主,两种干预因素共同作用的结果。

【Objective】To investigate the effect of Ginkgo biloba extract （GBE） on the concentration of SOD,GSH-Px,and MDA in rat ischemia brain in different cerebral temperature.【Methods】The model of rat middle cerebral artery ischemia reperfusion was established,induced to target cerebral temperature,then the concentration of SOD,GSH-Px,and MDA in variant ischemia brain group of high temperature,normal temperature,and subhypothermia was detected.【Results】 ① Compared with sham operated group in normal temperature,the concentration of SOD and GSH-Px were predominantly decreased while the increasing of MDA concentration in cerebral ischemia control group and GBE group（P 0.01）.②Compared with cerebral ischemia control group in normal temperature,the concentration of SOD and GSH-Px were increased while the decreasing of MDA concentration in ginkgo leaf group in normal temperature and cerebral ischemia group in subhypothermia （P 0.01）.③Compared with GBE group in normal temperature,SOD and GSH-Px concentration was predominantly decreased （P 0.001）,MDA con-centration was notably increased （P 0.01） in GBE group in mild high temperature;SOD and GSH-Px concentration was predominantly increased （P 0.01）,MDA concentration was notably decreased （P 0.001） in cerebral ischemia group and GBE group in subhypothermia.④Compared with cerebral ischemia group in subhypothermia,SOD and GSH-Px and MDA concentration had no distinct diversity （P 0.05） in GBE group under subhypothermia.【Conclusion】① During the processes of cerebral ischemic reperfusion,different brain temperature may affect the reparative effect of GBE on the disbalance between antioxidase and oxygen free radical.The GBE can restore the balance between antioxidase and oxygen free radical under normal temperature;those effect may be dismissed at mild hyperthermia while enhanced under subhypothermia,then enhance neuroprotection of GBE.② It suggests that the reparation of antioxidase/oxygen free radical disbalance isn＇t the result of either subhypothermia or GBE intervention factor,but the main effect of subhypothermia and the combination of both factors.