规律性有氧运动对脑缺血大鼠的脑保护作用及机制探讨

Protective effect and mechanism of regular aerobic exercise on cerebral ischemia in rats

目的研究规律性的有氧运动对脑缺血大鼠的脑组织的保护机制。方法按照随机数字表法将40只SPF级SD雄性大鼠随机分为假手术组、模型组、实验组、对照组,模型组、实验组、对照组大鼠采用线栓法制备大鼠脑中动脉脑缺血(middle cerebral artery occlusion,MCAO)动物模型,假手术组大鼠只进行穿线,不结扎;实验组大鼠每日进行有规律的有氧运动(跑台跑步):运动强度为20 m/min,每日3次,每次20 min,每次间隔2 h,对照组大鼠每日给以1.08 mg/m L的尼莫地平灌胃给药。激光散斑成像观察大鼠大脑皮层血流变化;脑电图检测大鼠大脑皮层总功率的变化;2,3,5-三苯基氯化四氮唑(2,3,5-triphenyltetrazolium chloride,TTC)染色检测大鼠的脑梗死面积;蛋白免疫印迹检测各组大鼠脑组织中脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)、生长相关蛋白(growth-associated protein 43,GAP43)的表达。结果与假手术组相比,模型组、实验组、对照组大鼠大脑皮层血流灌注量、大脑皮层总功率、BDNF、GAP43的表达明显下降(P<0.05),梗死面积明显升高(P<0.05),与模型组相比,实验组、对照组大鼠大脑皮层血流灌注量、大脑皮层总功率、BDNF、GAP43的表达明显升高(P<0.05),梗死面积明显下降(P<0.05)。结论规律性的有氧运动明显改善脑缺血大鼠的血流灌注和脑部微血管循环障碍,降低其脑组织的梗死面积,抑制炎性的级联放大,可能与激活BDNF/GAP43通路有关。

Objective To investigate the protective effect and mechanism of regular aerobic exercise on cerebral ischemia in rats.Methods According to the random number table method,40 specific pathogen-free male SD rats were randomly divided into sham operation,model,experimental,and control groups.The middle cerebral artery occlusion(MCAO)rat model was constructed by the thread plug method.Rats in the sham operation group were threaded without ligation.Rats in the experimental group performed regular aerobic exercise(running on a treadmill)every day with an exercise intensity of 20 m/min,three times a day,20 min each time,and 2 h apart each time.Rats in the control group were given 1.08 mg/m L nimodipine by gavage daily.Laser speckle imaging was used to observe changes in blood flow in the cerebral cortex.Electroencephalograms were used to detect changes in total power in the cerebral cortex.2,3,5-triphenyltetrazolium chloride staining was used to detect cerebral infarct areas.Western Blot was used to detect the expression of brain-derived neurotrophic factor(BDNF)and growth-associated protein 43(GAP43)in brain tissue.Results Compared with the sham group,the cerebral cortex blood perfusion,total cerebral cortex power,and expression of BDNF and GAP43 in the model,experimental,and control groups were significantly decreased(P<0.05),and infarct area was significantly increased(P<0.05).Compared with the model group,the cerebral cortex blood perfusion,total cerebral cortex power,and expression of BDNF and GAP43 in the experimental and control groups were significantly increased(P<0.05),and the infarct area was significantly decreased(P<0.05).Conclusions Regular aerobic exercise can significantly improve blood perfusion and cerebral microvascular circulatory disorders in cerebral ischemic rats,reduce infarct size in brain tissue,and inhibit the inflammatory cascade,which may be related to activation of the BDNF/GAP43 pathway.