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

摘要

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 neurotro-phic factor，GDNF）、GDNF 家族受体α－1信使 RNA （GDNF？family receptor α－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（E 1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（0．3mL／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.