游泳康复训练通过钙调蛋白激酶Ⅱ对脑缺血再灌注沙鼠学习记忆功能的影响

Effects of swimming rehabilitation training on learning and memory function and CaMK Ⅱin gerbils with cerebral ischemia reperfusion

目的探讨游泳康复训练对脑缺血再灌注沙鼠学习记忆功能障碍的保护作用及其机制。方法按随机数表法将40只成年健康雄性沙鼠随机分为假手术组(Sham组)、假手术+游泳组(Sham+S组)、脑缺血/再灌注组(I/R组)、脑缺血/再灌注+游泳组(I/R+S组),每组10只。I/R组和I/R+S组采用颈总动脉双侧血管阻断构建脑缺血/再灌注的沙鼠模型;Sham组和Sham+S组只暴露双侧颈总动脉,但不行动脉夹闭。采用Morris水迷宫检测大鼠学习记忆功能改变;应用检测试剂盒分析检测海马神经元氧化应激损伤情况;利用Western blot技术检测海马组织Bax、Bcl-2和CaMKⅡ蛋白表达变化。结果与Sham组相比,I/R组定位巡航时间延长、穿梭次数减少,差异具有统计学意义(P<0.01);I/R+S组与I/R组相比,定位巡航时间明显缩短、穿梭次数明显增加(P<0.01)。与Sham组[SOD:(123.13±7.50)U/mg,GSH:(42.10±2.17)μg/g,GSH-Px:(61.37±2.51)μg/g,MDA:(2.91±0.23)nmol/mg]相比,I/R组SOD、GSH、GSH-Px活性明显降低,MDA含量明显增加[SOD:(75.50±6.96)U/mg,GSH:(22.50±1.64)μg/g,GSH-Px:(33.15±2.04)μg/g,MDA:(5.96±0.32)nmol/mg];与I/R组相比,I/R+S组上述变化明显逆转[SOD:(110.30±5.90)U/mg,GSH:(34.31±1.73)μg/g,GSH-Px:(50.13±2.31)μg/g,MDA:(3.54±0.29)nmol/mg],均差异具有统计学意义(均P<0.01)。与Sham组相比,I/R组沙鼠海马组织Bax蛋白表达升高,Bcl-2蛋白和p-CaMKⅡ蛋白表达降低,均差异具有统计学意义(均P<0.05);与I/R组相比,I/R+S组沙鼠海马组织Bax蛋白表达下降,Bcl-2蛋白和p-CaMKⅡ蛋白表达升高,均差异有统计学意义(均P<0.05)。结论游泳康复训练可通过抗氧化应激和抗凋亡改善沙鼠缺血再灌注所致的学习记忆障碍,此作用可能与CaMKⅡ信号通路有关。

Objective To explore the protective effect and mechanism of swimming rehabilitation training on learning and memory impairment of cerebral ischemia reperfusion gerbil.Methods Forty adult healthy male gerbils were randomly divided into sham group,sham+swimming group(Sham+S group),cerebral ischemia/reperfusion group(I/R group),cerebral ischemia/reperfusion+swimming group(I/R+S group),with 10 rats in each group.The gerbil models of cerebral ischemia/reperfusion in I/R group and I/R+S group were established by blocking bilateral common carotid artery,while for gerbils in Sham group and Sham+S group,only bilateral common carotid arteries of gerbils were exposed,but no arteries were clamped.Morris water maze was used to detect the changes of learning and memory function in rats.Oxidative stress injury in hippocampal neurons was detected by detection kit analysis.And the expression of Bax,Bcl-2 and CaMKⅡprotein in hippocampal tissue was detected by Western blot.Results Compared with Sham group,the gerbils in I/R group had longer positioning cruise time and less shuttle times(both P<0.01).Compared with I/R group,the positioning cruise time and shuttle times in I/R+S group were significantly shortened and increased respectively(both P<0.01).Compared with sham group(SOD:(123.13±7.50)U/mg,GSH:(42.10±2.17)μg/g,GSH-Px:(61.37±2.51)μg/g,MDA:(2.91±0.23)nmol/mg),the activities of SOD,GSH,GSH-Px in I/R group decreased significantly,while the content of MDA increased significantly(SOD:(75.50±6.96)U/mg,GSH:(22.50±1.64)μg/g,GSH-Px:(33.15±2.04)μg/g,MDA:(5.96±0.32)nmol/mg;all P<0.01).Furthermore,compared with I/R group,the above indexes in I/R+S group were significantly reversed(SOD:(110.30±5.90)U/mg,GSH:(34.31±1.73)μg/g,GSH-Px:(50.13±2.31)μg/g,MDA:(3.57±0.29)nmol/mg;all P<0.01).Compared with Sham group,the expression of Bax protein in hippocampus of gerbils in I/R group was increased,while the expression of Bcl-2 protein and p-CaMKⅡprotein was decreased(all P<0.05).Compared with I/R group,the expression of Bax protein in hippocampus of gerbils in I/R+S group was decreased,while the expression of Bcl-2 protein and p-CaMKⅡprotein was increased(all P<0.05).Conclusion Swimming rehabilitation training can improve learning and memory impairment of gerbils after ischemia-reperfusion through anti-oxidative stress and anti-apoptosis,which may be related to CaMKⅡsignaling system.