摘要
目的 观察运动训练联合电针对缺血性脑卒中模型大鼠突触可塑性及PI3K/Akt信号通路相关蛋白表达量的影响,探讨运动训练联合电针治疗缺血性脑卒中模型大鼠的作用机制.方法 将50只SPF级雄性SD大鼠按随机数字表法分为假手术组、模型组、电针组、运动组和联合组,每组10只.其中模型组、电针组、运动组和联合组参照Zea-Longa线栓法构建大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)的缺血性脑卒中大鼠模型,假手术组仅分离左侧颈动脉,不插入线栓,直接缝合,当Zea-Longa神经功能缺损评分为1～3分则表示模型制备成功.电针组电针百会、神庭穴,30 min/次;运动组予以跑台训练,30 min/次;联合组先予跑台训练30 min,再电针百会、神庭穴30 min.各组干预周期均为2周,1次/d,5 d/周.模型组、假手术组大鼠仅予以同等抓取及固定,不做任何干预.干预前后采用Zea-Longa神经功能缺损评分评定大鼠神经功能缺损情况;7.0T小动物核磁共振扫描观察脑梗死体积占比;干预后采用Morris水迷宫实验观察5组大鼠逃避潜伏期以及穿越平台次数;采用Golgi染色法观察左侧海马CA1区树突棘形态及数量变化;采用Western blot检测大鼠左侧海马组织PI3K、Akt、p-PI3K、p-Akt蛋白表达量.结果 与假手术组比较,模型组大鼠Zea-Longa神经功能缺损评分、脑梗死体积占比显著升高,Morris水迷宫实验逃避潜伏期、穿越平台次数显著增加,树突棘形态呈现脱落萎缩,排列紊乱,数量减少,p-PI3K/PI3K、p-Akt/Akt比值显著降低(P均＜0.05).与模型组比较,电针组、运动组和联合组大鼠干预后Zea-Longa神经功能缺损评分降低,脑梗死体积占比减少,Morris水迷宫实验逃避潜伏期减少、穿越平台次数增加,树突棘形态更完整、排列整齐、数量增多,p-PI3K/PI3K、p-Akt/Akt比值显著升高(P均＜0.05).与电针组、运动组比较,联合组干预后Zea-Longa神经功能缺损评分显著降低,脑梗死体积占比显著下降,Morris水迷宫实验逃避潜伏期显著减少,且穿越平台次数显著增加,树突棘形态更加完整、数量明显增多,p-PI3K/PI3K、p-Akt/Akt比值显著升高(P均＜0.05).结论 运动训练联合电针可减轻缺血性脑卒中大鼠神经功能损伤,缩小脑梗死体积,促进海马突触可塑性修复,改善学习记忆能力,其机制可能与调控PI3K/Akt信号通路有关.
Abstract
Objective:To explore the effect and mechanism of exercise training combined with electroacupuncture on synaptic plasticity and PI3K/AKT signaling pathway-related protein expression in ischemic stroke model rats.Methods:Fifty SPF male SD rats were randomly divided into the sham operation group,model group,electroacupuncture group,exercise group and combination group,with 10 rats in each group.The ischemic stroke rat model of middle cerebral artery occlusion(MCAO)was established by the modified Zea-Longa thread occlusion method in the latter four groups,while rats in the sham operation group were separated from the left carotid artery without inserting the thread plug and then directly sutured it.The successful establishment of the model was indicated when the Zea-Longa score was 1 to 3.The electroacupuncture group received electroacupuncture on Baihui and Shenting acupoints for 30 minutes;the exercise group was given treadmill training for 30 minutes;the combination group was treated with treadmill train-ing and then received electroacupuncture intervention for 30 minutes each.All groups were intervened for 2 weeks,once per day for 5 days per week.The rats in the model and sham operation groups were only equally grasped and fixed without any intervention.Zea-Longa scoring system was used to evaluate the neurological impairment of rats.Observation of the proportion of cerebral infarction volume by 7.0 T small animal magnetic resonance scanning.Morris water maze test was used to observe the escape latency and the number of times crossing the platform of rats in 5 groups.Morphological and quantitative changes of dendritic spines in left hippo-campal CA1 region were observed by Golgi staining.Western Blot was used to detect the protein expression of PI3K,AKT,p-PI3K and p-AKT in the left hippocampal tissue of rats.Results:Compared with the sham operation group,the Zea-Longa score increased significantly in the model group,the volume ratio of cerebral infarction increased significantly,the escape latency and the number of crossings of the Morris water maze experiment increased significantly,dendritic spines were atrophy,disordered,and reduced in num-ber,and the ratio of p-PI3K/PI3K and p-AKT/AKT decreased significantly(P all＜0.05).Compared with the model group,the Zea-Longa score in the electroacupuncture,exercise and combination groups were reduced;the proportion of cerebral infarction vol-ume decreased in rats;the time of escape latency reduced and the number of crossing the platform increased;the dendritic spines were more complete in morphology,neatly arranged and increased in number;the p-PI3K/PI3K and p-AKT/AKT ratios were signifi-cantly higher(P all＜0.05).Compared with the electroacupuncture and exercise groups,the Zea-Longa score decreased significantly in the combination group;the proportion of cerebral infarction volume decreased significantly;the time of escape latency reduced sig-nificantly,and the number of crossing the platform increased significantly;the morphology of hippocampal CA1 dendritic spines were more complete and increased in number;the ratios of p-PI3K/PI3K and p-AKT/AKT were significantly up-regulated(P all＜0.05).Con-clusion:Exercise training combined with electroacupuncture could reduce the neurological impairment,decrease the volume of cerebral infarction,promote the repair of hippocampal synaptic plasticity,and improve the learning and memory ability in ischemic stroke rats.The mechanism may be related to the regulation of PI3K/AKT signaling pathway.
维普
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