中枢疲劳恢复期大鼠海马GDNF、GFRα-1mRNA及其蛋白表达的动态变化特征

Dynamic characteristics of expression of GDNF,GFRα-1mRNA and protein in rat hippocampus after the central fatigue

目的:探讨大鼠海马组织胶质细胞源性神经营养因子(glial cell line-derived neurotrophic factor,GDNF)、GDNF家族受体α-1信使RNA(GDNF?family receptorα-1mRNA,GFRα-1mRNA)及其蛋白表达在中枢疲劳后恢复期不同时相的动态变化特征。方法:雄性2月龄SD大鼠32只,随机分为对照组(C组,n=8)、实验组(E组,n=24);E组进行7周疲劳模型运动后,又随机分为运动后即刻组(E0组,n=8)、恢复期12 h组(E1组,n=8)、恢复期24 h组(E2组,n=8)。C组正常笼养,E组进行7周递增负荷跑台训练。经7周疲劳模型运动后即刻,C组和E0组腹腔注射10%水合氯醛糖浆(0.3m L/100g)麻醉后取海马组织,用于测定5-羟色胺(5-hydroxytryptamine,5-HT)、多巴胺(dopamine,DA)、GDNF、GFRα-1mRNA及其蛋白表达;E1组和E2组分别在恢复期12 h、24 h做上述同样取材和测试。结果:1)大鼠经7周递增负荷跑台训练后即刻,海马组织5-HT升高(P<0.01),DA下降(P<0.01),DA/5-HT下降(P<0.05)。2)运动后即刻海马组织GDNF、GFRα-1mRNA相对表达率和GDNF、GFRα-1平均蛋白表达水平升高;恢复期12 h高于C组和E0组(P<0.01);恢复期24 h降低并低于E1组(P<0.01)。结论:1)经7周疲劳模型运动后大鼠已经出现中枢疲劳。2)运动性中枢疲劳后大鼠海马组织GDNF、GFRα-1mRNA及其蛋白表达水平上升,提示GDNF和GFRα-1可能参与了中枢疲劳恢复的神经生物学调控过程。

Objective:To investigate the dynamic changing features of the glial cell line -derived neu-rotrophic factor (GDNF),GDNF family receptor α-1mRNA (GFRα-1mRNA)and relative pro-tein expression in hippocampus of rats during different phases of recovery period after fatigue.Meth-ods:32 male SD rats (2 month old)were randomly divided into control group (C group,n =8)and experimental groups (E group,n =24).At the sampling time,the experimental groups were ran-domly divided into the group immediately (E0,n =8),12 h (E1,n =8),and 24 h (E2,n =8) after exhaustive running.All rats in experimental groups were assigned a 7 -week training program increasing load by degrees with a final exhaustive running.The 5 -HT,DA,and the expressions of GDNF and GFRα-1mRNA from hippocampus of rats were measured.Results:All rats in experimen-tal groups were assigned a 7 -week training program increasing load by degrees.Immediately after the last exhaustive running:1)the hippocampus 5 -HT was significantly higher(P <0.05),and DA,DA /5 -HT were significantly lower (P <0.01)than those of C group.2)The correspondence expression rates of GDNF and GFRα-1mRNA,and the protein expressions of GDNF and GFRα-1 were higher than those of C respectively.12h post -exercise,all indexes of E1 group were higher than those of C and E0,respectively (P <0.01 ).24 h post -exercise,all indexes of E2 group were lower than those of E1(P <0.01).Conclusion:1)The rat was instantly reach central fatigue after treadmill movement after 7 weeks.2)While exercise -induced central fatigue occurs,there are up -regulations in the levels of expression of GDNF,GFRα-1mRNA and protein in rat hippo-campus,which indicates that both GDNF and GFRα-1mRNA have participated in neurobiological regulation process recovered from exercise fatigue.