力竭运动后大鼠海马CA1区自由基、下丘脑GABA及HPA轴的动态变化  

Dynamic Changes in Free Radical in Hippocampus CA1 Neuron,GABA Concentration in Hypothalamus and the Activity of HPA Axis Induced by Acute Exhaustion Swimming

作　　者：陆小香[1] 张蕴琨[1] 江年 

机构地区：[1]南京体育学院运动人体科学系,南京210014 [2]南京市体育科学研究所,南京210016

出　　处：《中国运动医学杂志》2007年第5期563-567,共5页Chinese Journal of Sports Medicine

基　　金：江苏省体育局课题基金(编号:TY5105)

摘　　要：目的:探讨运动性疲劳时神经内分泌系统的中枢调控机制。方法:50只SD大鼠随机分为安静对照组和力竭性游泳运动组,力竭组大鼠进行一次性力竭游泳运动,运动后即刻、1h、3h和24h断头取材。用放免法测定下丘脑促肾上腺激素释放激素(CRH)、血清肾上腺皮质激素(ACTH)和血清皮质酮(C);DNS-Cl荧光光度法测定下丘脑γ-氨基丁酸(GABA)含量;顺磁共振波谱法测定PBN自旋捕获剂捕获的海马CA1区自由基含量。结果:(1)力竭运动后即刻和恢复1小时组大鼠下丘脑CRH显著低于安静对照组;运动后即刻组血清ACTH浓度低于安静对照组,运动后1小时和3小时组高于安静对照组,但均无显著性差异;运动后即刻组血清C明显高于安静对照组。(2)与安静对照组相比,力竭运动后即刻、1小时和3小时组大鼠下丘脑GABA含量均显著升高。(3)与安静对照组相比,运动后即刻组大鼠海马CA1区自由基信号强度显著增强。(4)下丘脑GABA含量与下丘脑CRH呈显著负相关;海马CA1区自由基信号强度与下丘脑GABA含量呈显著正相关;海马CA1区自由基信号强度与下丘脑CRH呈显著负相关。结论:(1)下丘脑GABA可能通过直接作用于CRH神经元参与抑制运动应激时下丘脑-垂体-肾上腺皮质(HPA)轴的过度激活,并将运动疲劳时中枢的抑制状态传递到外周,使机体免受HPA轴过度激活带来的损伤。(2)力竭性运动时海马CA1区神经元自由基的增加使兴奋性增强,并可能通过Glu-GABA突触联系间接对HPA轴活性进行抑制。To determine the potential role of hippocampus and hypothalamus in regulating mech- anism of neuroendocrine during exercise-induced fatigue, fluorescence analysis method was used to detect hypothalamus γ-aminobutyric acid （GABA）concentration, electron paramagnetic resonance （EPR）was used to observe free radical generation in hippocampus CA1 neurons, and radioimmunoas- say was applied to analyze the activity of hypothalamus-pituitary-adrenal（HPA） axis in recovery phase after acute exhausting swimming. Results showed that after exhaustion swimming, the concen- trations of hypothalamus corticotropin releasing hormone（CRH） in group B1 （immediate after exhaus- tion swimming） and group B2 （1 hour after exhaustion swimming） were significantly lower than that in group A （sedentary control）. The change in serum adrenocorticotropic hormone（ACTH） was simi- lar to CRH without significant difference. The concentration of serum cort（C） was significantly high- er in group A. As compared with group A, GABA levels in groups B1, B2, B3 （3 hour after exhaus- tion swimming） were higher. As compared with group A, free radical generation in hippocampus CA1 neurons increased significantly in group B1. There was a negative correlation between hypothalamus GABA and CRH concentration. The free radical generation correlated positively with hypothalamusGABA concentration, and correlated negatively with hypothalamus CRH concentration. It was con- cluded that （1） hypothalamus GABA probably took part in inhibiting the excessive activation of HPA induced by exercise stress; （2） free radical generation enhanced the excitability of hippocampus CA1 neurons, and inhibited the activity of HPA indirectly by Glu--GABA synapses connection.

关 键 词：力竭运动 运动性疲劳 HPA轴 下丘脑GABA 海马自由基 

分 类 号：R87[医药卫生—运动医学]