纹状体A_(2A)R/D_2DR表达及DARPP-32磷酸化在运动疲劳调控中的作用  

Effect of Striatal A_(2A)R/D_2DR Expression and DARPP-32 Phosphorylation on Exercise Induced Fatigue Regulation

作　　者：刘军[1,2] 刘晓莉[1] 乔德才[1] 

机构地区：[1]北京师范大学体育与运动学院,北京100875 [2]西安体育学院健康科学系,西安710068

出　　处：《西安体育学院学报》2015年第4期460-467,共8页Journal of Xi'an Physical Education University

基　　金：国家自然科学基金资助项目(31171138);北京市自然科学基金资助项目(5142012)

摘　　要：目的通过观察跑台运动大鼠力竭前后纹状体腺苷A2A受体/多巴胺D2受体(A2AR/D2DR)表达、磷蛋白DARPP-32表达及其磷酸化,探讨A2AR/D2DR通过纹状体-苍白球通路对运动疲劳调控的可能机制,为寻求新的抗疲劳药物及手段提供理论与实验依据。方法实验选用8周龄雄性健康Wistar大鼠30只,随机分为安静对照组(CG)、力竭即刻组(EG)和力竭后恢复90 min(RG)组,每组10只,建立一次性力竭运动疲劳模型。采用免疫荧光双标技术,观察大鼠安静状态、力竭即刻及恢复90 min时纹状体A2AR和D2DR表达的变化;采用免疫荧光和免疫印迹技术,观察大鼠在安静状态、力竭即刻及恢复90 min时纹状体苍白球神经元(D2-MSNs)内DARPP-32表达及磷酸化水平的变化特征。结果大鼠跑台运动至力竭时纹状体A2AR阳性细胞个数显著增高(P<0.01),D2DR阳性细胞个数显著下降(P<0.01),且A2AR和D2DR共表达于D2-MSNs的胞膜上;恢复90 min时A2AR阳性细胞依然显著高于安静状态(P<0.05),D2DR依然低于安静状态(P<0.05);相比安静状态,力竭运动即刻Thr34-DARPP-32磷酸化增加(P<0.01),恢复90 min时表达显著下降(P<0.05),p-Thr34-DARPP-32/DARPP-32比值增加(P<0.01),恢复90 min后有所下降,但没有显著性差异。结论 A2AR和D2DR共同参与了对运动中枢疲劳的调控;大鼠力竭运动过程中,A2AR和D2DR是通过调节Thr34-DARPP-32磷酸化程度而发挥对运动疲劳的调控作用;运动至力竭时A2AR和D2DR调节作用异常,可能是运动疲劳时纹状体神经元异常兴奋的原因之一。Objective To investigate possible mechanism of adenosine A2A receptor/dopamine D2 receptor （A2A R/D2DR） modulating exercise - induced fatigue via striato - pallidal pathway, this study observed the expression changes of striatal A2A R/D2DR, and observed the expression and phosphorylation of phosphoprotein DARPP -32 in pre and post - exhaustive treadmill exercise, it can help to provide the theoretical and experimental basis for seeking the new anti - fatigue drugs and methods. Methods Thirty healthy male wistar rats were randomly divided into the control group, exhaustion group and re- covering group after exhaustion （n = 10）. To establish a rat model of one single bout of exhaustive exercise on treadmill. By the double labeled immunofluorescence technique, expression of A2A R and De DR in the striatum were studied at the three time points ： at rest, exhausted and 90 minutes after exhausted, to analyze the relationship between the change of rat behavior ability and the expression of DaDR and A2AR, and to study the function of D2DR and A2AR in regulating neuronal activity in the striatum. The expressions of DARPP -32 and its phosphorylation which is the signal integration factor in the striatal and pallidal neurons were observed with immunofluorescenee and western blot at rest, fatigue point and during the recovery, to study further the action mechanisms of D2DR and A2AR in modulating striatal neuronal functional activity. Results The number of A2AR positive cells in the striatum increased significantly （P 〈0.01 ）and the number of D2DR positive cells de-creased significantly（ P 〈 0.01 ）when rats ran to exhaustive on the treadmill, in addition, A2AR and DE DR coexpress on the cell membrane of striatal pallidal neurons. Even after recovery of 90 min, the number of A2A R positive cells is still higher than that at rest （ P 〈 0.05 ）, and the number of DE DR positive cells is still lower than that at rest （ P 〈 0.05 ）. The expres- sion of Thr34 - DARPP - 32 phosphorylation increased ma

关 键 词：运动性疲劳 纹状体 腺苷A2A受体 多巴胺D_2受体 DARPP-32 

分 类 号：G804.7[文化科学—运动人体科学]