长期运动预处理对缺血性脑卒中大鼠脑组织损伤和神经功能障碍的改善作用及其可能机制

Improvement effects of preconditioning with long-term exercises on brain tissue injury and neurological dysfunction in rats with ischemic stroke and its possible mechanism

目的探讨长期运动预处理对缺血性脑卒中大鼠脑组织损伤和神经功能障碍的改善作用及其可能机制。方法将36只大鼠随机分为假手术组、脑缺血组和运动+脑缺血组,各12只。运动+脑缺血组大鼠进行连续4周的跑步和游泳锻炼,其他两组自由活动,随后应用线栓法构建中动脉脑缺血模型(脑缺血组和运动+脑缺血组)。建模24 h后评估大鼠神经功能缺损情况,过量麻醉处死大鼠后取脑组织,评估脑水肿和脑梗死程度,并检测海马与前额皮层组织中Toll样受体4(TLR4)、离子化钙结合适配分子1(Iba1)、肿瘤坏死因子α(TNF-α)、白细胞介素(IL)-1β与IL-6的表达情况。结果脑缺血组、运动+脑缺血组、假手术组大鼠的神经功能缺损评分依次降低,脑水肿和脑梗死程度依次减轻(均P<0.05)。与假手术组相比,脑缺血组大鼠海马区与前额皮层中Iba1、TLR4、TNF-α、IL-1β与IL-6的表达量均增加(均P<0.05);与脑缺血组相比,运动+脑缺血组海马区与前额皮层中Iba1、TLR4、TNF-α、IL-1β与IL-6的表达量均降低(均P<0.05)。结论长期运动可减轻缺血性脑卒中大鼠的脑组织损伤和神经功能障碍,其或通过抑制小胶质细胞激活引起的炎性因子反应发挥作用。

Objective To investigate the improvement effects of preconditioning with long-term exercises on brain tissue injury and neurological dysfunction in rats with ischemic stroke and its possible mechanism.Methods Thirty-six rats were randomly divided into sham-operation group,cerebral ischemia group and exercise+cerebral ischemia group,with 12 rats in each group.Rats in the exercise+cerebral ischemia group took exercises,running and swimming,for consecutive four weeks,whereas rats in the other two groups moved around freely.And then the models of middle arterial cerebral ischemia were established using the suturing method in the cerebral ischemia and exercise+cerebral ischemia groups.After 24 hours of the modeling,rats'neurological deficit condition was assessed.Rats'brain tissues were harvested after they had been killed by overdose anesthesia,and the severities of cerebral edema and cerebral infarction were evaluated.Besides,the expression of Toll-like receptor 4(TLR4),ionized calcium-binding adapter molecule 1(Iba1),tumor necrosis factorα(TNF-α),interleukin(IL)-1β,and IL-6 in hippocampus and prefrontal cortex tissues was detected.Results Rats'neurological deficit score declined and the severities of cerebral edema and cerebral infarction decreased in the cerebral ischemia group,exercise+cerebral ischemia group and sham-operation group successively(all P<0.05).Compared with the sham-operation group,rats in the cerebral ischemia group exhibited increased expression of Iba1,TLR4,TNF-α,IL-1β,and IL-6 in the hippocampus and prefrontal cortex tissues(all P<0.05).Compared with the cerebral ischemia group,the exercise+cerebral ischemia group yielded reduced expression of Iba1,TLR4,TNF-α,IL-1β,and IL-6 in the hippocampus and prefrontal cortex tissues(all P<0.05).Conclusion Long-term exercises can ameliorate brain tissue injury and neurological dysfunction in rats with ischemic stroke,which might exert effects by inhibiting inflammatory factors response caused by the activation of microglia.