| （1.国防科学技术大学 体育与基层工作系，湖南 长沙 410072；2.湖南农业大学 体育艺术学院，湖南 长沙 410128） 摘 要：以纹状体为目标核团，探讨预运动训练改善脑缺血损伤的机制。将雄性Wistar大鼠随机分为安静对照微透析组(CM)、安静对照染色组(CS)、预运动训练微透析组(EM)及预运动训练染色组(ES)(每组10只)。首先在CM及EM组大鼠纹状体内埋植微透析探针导轨，手术恢复后，对EM及ES组大鼠进行为期4周的有氧运动训练。训练结束后，对所有大鼠实施大脑中动脉阻塞手术，并运用微透析-高效液相色谱电化学联用技术对缺血及再灌注过程中大鼠纹状体细胞外液多巴胺(DA)、5-羟色胺(5-HT)、去甲肾上腺素(NE)及各自代谢产物二羟苯乙酸(DOPAC)、5-羟吲哚乙酸(5-HIAA)、3-甲基4-羟基苯乙二醇(MHPG)的变化进行观察。CS及ES组大鼠，在大脑中动脉阻塞手术恢复24 h，取脑进行TTC染色。染色结果发现，与CS组相比，ES组大鼠纹状体损伤面积比例显著降低(P<0.05)。微透析研究结果发现，缺血过程中CM及EM组大鼠纹状胞体外DA水平均呈快速上升趋势，且EM组上升幅度低于CM组(P<0.05)，随后两组DA水平均逐渐下降，再灌注过程中基本稳定于基线以下水平。DA代谢产物DOPAC变化趋势为，缺血过程中两组大鼠纹状体胞外DOPAC均快速下降，但EM组下降幅度小于CM组(P<0.05)，随后两组DOPAC水平逐渐上升，再灌注过程中DOPAC水平呈先快速上升后逐步下降趋势。缺血及再灌注过程中5-HT、NE及其各自代谢产物水平变化与DA、DOPAC变化趋势基本一致。以上结果表明，科学、合理的预运动训练是保护缺血性脑损伤的一种有效手段，纹状体作为预运动训练发挥其神经保护作用的靶标核团之一，缺血及再灌注过程中，其胞外单胺类神经递质及其代谢产物水平的改变可能是预运动训练实现保护功能的途径之一。 |
PENG Xiong-hui1，WU Qiu-fen2，YAN Jie-xing1，XIE Song-lin1，WANG Da-lei1
| （1.Departmen of Physical Education，National University of Defense Technology，Changsha 410072，China；2.Departmen of Physical Education，Hunan Agricultural University，Changsha 410128，China) Abstract: In order to probe into the mechanism of exercise preconditioning improving cerebral ischemic injury by basing the target nucleus on the striatum, the authors divided male Wistar rats randomly into a calm control mi-crodialysis group (CM), a calm control staining group (CS), an exercise preconditioning microdialysis group (EM) and an exercise preconditioning staining group (ES) (each of which consists of 10 rats), implanted a microdialysis probe guide cannula into the striatum of the rats in groups CM and EM, then let the rats in groups EM and ES un-dergo 4-week aerobic training after surgery recovery, performed middle cerebral artery occlusion surgery on all the rats after training was completed, applied the microdialysis-HPLC-electrochemistry combined technology to observe the changing of dopamine (DA), 5-hydroxytryptamine (5-HT), norepinephrine (NE) and their respective metabolites, dihy-droxy phenyl acetic acid (DOPAC), 5-hydroxy indole acetic acid (5-HIAA) and 3-methyl 4-hydroxy benzene ethylene gly-col (MHPG) in the extracellular fluid of the striatum of the rats in the process of ischemia and in reperfusion, and took out the brains of the rats in groups CS and ES for TTC staining after the rats had gone through 24 hours of recovery from middle cerebral artery occlusion surgery. From staining results the authors found that the damaged area of the striatum of the rats in group ES decreased significantly (P<0.05) as compared with that of the rats in group CS. From microdialysis research results the authors revealed the following findings: in the process of ischemia, the extracellular DA level of the striatum of the rats in groups CM and EM showed a trend of rapid increasing, the increasing magnitude of the rats in group EM was smaller than that of the rats in group CM (P<0.05), then the DA level of the rats in the two groups decreased gradually, and stabilized ba-sically at a level below the baseline in the process of reperfusion. The trend of changing of DA metabolite DOPAC was as follows: in the process of ischemia, the extracellular DOPAC of the striatum of the rats in two groups decreased rapidly, but the decreasing magnitude of the rats in group EM was smaller than that of the rats in group CM (P<0.05), then the DOPAC level of the rats in the two groups increased gradually, in the process of reperfusion, the DOPAC level showed a trend of rapid increasing followed by gradual decreasing. In the process of ischemia and reperfusion, the changing of the levels of 5-HT, NE and their respective metabolites was basically consistent with the trend of changing of DA and DOPAC. The said results indicated the followings: scientific and rational exercise preconditioning is an effective means to protect ischemic brain injury; in the process of ischemia and reperfusion, the changing of the levels of extracellular monoamine neurotrans-mitters and their metabolites in the striatum used as one of the target nuclei for exercise preconditioning to exert its nerve protecting function may be one of the ways for exercise preconditioning to realize its protecting function. |
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