摘要
运动耐力与骨骼肌中乳酸的产生和消除密切相关。有文献表明,核因子E2相关因子2(nuclear factor erythroid-2-related factor 2,Nrf2)在运动引起的骨骼肌抗氧化、线粒体的生物合成和能量代谢中起着重要作用。然而,目前尚不明确Nrf2激活对低氧环境下的乳酸代谢和运动耐力的影响。本研究通过预先给与小鼠补充Nrf2激活剂萝卜硫素(sulforaphane,SFN),而后给小鼠在低氧环境下(11.2%O2)进行一次性递增负荷至力竭的运动,观察小鼠在低氧环境下的运动耐力和红白肌乳酸代谢的变化。结果表明,在低氧下一次性力竭运动显著增加小鼠血乳酸水平(P<0.05)。但补充SFN组小鼠运动后血乳酸水平仅是未补充组的76%(P<0.05),并且补充SFN小鼠在低氧下进行力竭运动的跑动距离从577.0±52.9m增加到636.3±101.4m(P<0.05),力竭运动时间也提高了1.1倍(P<0.05)。采用免疫印迹法测定骨骼肌中蛋白质的相对表达。结果显示,在红肌中,SFN-Control/SFN-Exercise组与相应PBS-Control/PBS-exercise组相比,Nrf2和磷酸化-Nrf2(p-Nrf2)蛋白质表达水平均显著增加(P<0.05)。在白肌中,补充SFN诱导小鼠骨骼肌中的p-Nrf2表达在安静和运动后分别增加38%和52%(P<0.05)。另外,补充SFN与补充PBS相比,促进了小鼠在安静及一次性力竭运动后红肌中MCT1的表达(P<0.05)以及降低了SFN-Exercise组MCT4蛋白表达水平(P<0.05)。同时,与补充PBS相比,补充SFN小鼠红肌中乳酸脱氢酶B(LDH-B)蛋白表达增加了62%(P<0.05);小鼠白肌中,在安静及一次性力竭运动后,分别增加了1.35及1.31倍(P<0.05)。以上研究结果表明,补充SFN激活Nrf2可提高小鼠骨骼肌乳酸转运及代谢能力,这可能是在该低氧环境下的运动耐力增加的原因之一。该研究将对运动员、登山者和高原工作者等在高原运动、高原习服中SFN补充的应用,提供一定的理论参考依据。
Exercise endurance is closely related to the production and elimination of lactate in skeletal muscles.It has been confirmed in literature that nuclear factor erythroid-2-related factor 2(Nrf2)plays an important role in exercise-induced skeletal muscle antioxidant,mitochondrial biosynthesis and energy metabolism.However,it is still unclear whether Nrf2 activation has any effect on lactate metabolism and exercise endurance under hypoxic environment.In this study,sulforaphane(SFN),the Nrf2 activator,was pretreated to mice and then the mice were subjected to an exhaustive exercise under hypoxia(11.2%O2).The results showed that the exhaustive exercise significantly increased the blood lactate level in PBS-exercise group(P<0.05).However,this indicator in the SFN-exercise group was only 76% of that in the PBS-exercise group(P<0.05).Also,the running distance increased from 577.0±52.9 m to 636.3±101.4 m and the duration increased by 1.1 times as well(P<0.05).Western blotting was used to determine the relative expression of proteins in skeletal muscles.Protein expression levels of Nrf2 and p-Nrf2 in the SFN-control and SFN-exercise group were significantly increased in soleus(P<0.05).In extensor digitorum longus,SFN pretreatment induced the expression of p-Nrf2 increased by 38%and 52%,respectively(P<0.05).In addition,SFN pretreatment promoted MCT1 protein expression in SFN-Control/SFN-Exercise group and decreased MCT4 protein expression level in SFN-Exercise group(P<0.05).Meanwhile,the expression of LDH-B proteins in soleus was increased by 62%(P<0.05).In extensor digitorum longus,expression of LDH-B in the SFN-control and SFN-exercise group was increased by 1.35 times and 1.31 times,respectively(P<0.05).These results suggested that activation of Nrf2 by SFN could improve the lactate transport and metabolism capacity of skeletal muscle,which probably was one of the potential reasons for the increased exercise endurance of mice in the hypoxic environment.This study provided some theoretical reference for the practical ap
作者
王林佳
王瑞琪
李祥宁
张缨
WANG Lin-Jia;WANG Rui-Qi;LI Xiang-Ning;ZHANG Ying(Department of Sports Biochemistry,School of Sports Science,Beijing Sport University,Beijing 100084,China)
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2020年第12期1473-1480,共8页
Chinese Journal of Biochemistry and Molecular Biology
基金
北京体育大学“运动与体质健康”教育部重点实验室和国家体育总局应激适应重点实验室资金资助。
关键词
萝卜硫素
核因子E2相关因子2
氧化应激
乳酸
运动耐力
sulforaphane(SFN)
nuclear factor erythroid-2-related factor 2(Nrf2)
oxidative stress
lactate
exercise endurance
