不同运动强度影响大鼠脑缺血后神经功能修复机制的研究

Study on different exercises intensity impact of the repair of nervous function after cerebral ischemia in rat

目的探讨不同运动强度影响大鼠局灶性脑缺血后神经功能修复的机制。方法应用线栓法建立局灶性脑缺血SD大鼠模型,随机分为有氧运动组、疲劳运动组和对照组,每组8只,共24只;实施不同运动强度后评估每组大鼠神经功能缺失,透视电镜观察缺血神经细胞超微结构;测定缺血区域一氧化氮(NO)的含量和一氧化氮合酶(NOS)的活性;RT-PCR半定量分析缺血区域内皮细胞型一氧化氮合酶(eNOS)、诱导型一氧化氮合酶(iNOS)和神经元型一氧化氮合酶(nNOS)基因表达。结果对照组神经功能缺失评分高于有氧运动组,低于疲劳运动组,三组之间差异均有统计学意义(P<0.05);透视电镜发现对照组细胞形态和核不规则,有氧运动组细胞形态结构和细胞器完整,疲劳运动组细胞核分裂,线粒体肿胀;有氧运动组和疲劳运动组NO含量、NOS的活性以及eNOS、nNOS、iNOS基因表达量均高于对照组,NOS在有氧运动组和疲劳运动组中分别以eNOS和iNOS表达显著,所测指标在各组之间的差异均具有统计学意义(P<0.05)。结论 NO和NOS在脑缺血神经功能修复中发挥神经修复和神经毒性双重作用,有氧运动能够增强局部脑缺血区血液循环,促进神经修复,而疲劳运动促进NO和NOS过表达,产生局部神经毒性作用。

Objective To investigate the different exercises intensity impact of the repair of nerve iunction alter cerebral ischemia in rat. Methods 24 rats were underwent MCAO and then divided into randomly aerobict exercise group, haustive exercise group and control group with 8 rats in per group. The score of nevre function in different group was calculated, and the uhrastructure was observed. Both content of NO and activity of NOS in different group were compared. The expression of eNOS,nNOS and iNOS gene in different group were analyzed by RT-PCR. Results Control group was higher than aerobict exercise group, and lower than haustive exercise group on score of nevre function （P 〈 0.05）. Under the observation of transmission electromicroscope, the control group showed irregular cell＇s shape and organ, and the aerobiet exercise group of cell＇s shape and organ was regular, but the haustive exercise group showed nuclear fission. Aerobict exercise group and haustive exercise group were higher than control group on the content of NO, activity of NOS and expression of eNOS, nNOS and iNOS gene, but obviously expression eNOS of aerobict exercise group and iNOS of haustive exercise group by RT-PCR （P 〈 0.05）. Conclusion The different exercises intensity can made the dual effects with the nervous repair and nervous poison. Aerobict exercise can enhance the blood flucnce and improve the nerve function, but haustive exercise result in the nervous poison because of the excessive formation of NO and NOS.