支链氨基酸对一次性大强度离心运动后大鼠骨骼肌蛋白分解通路的影响  

Effects of branched-chain amino acid supplementation on skeletal muscle proteolytic pathways after exercise-induced muscle injury in rats

作　　者：魏昊 石云龙[1] 程燕 董云峰 曹维[1] 邱俊强[1] Wei Hao;Shi Yunlong;Cheng Yan;Dong Yunfeng;Cao Wei;Qiu Junqiang(Beijing Sport University,Beijing 100084,China)

机构地区：[1]北京体育大学,北京100084

出　　处：《卫生研究》2023年第4期565-572,共8页Journal of Hygiene Research

基　　金：中央高校基本科研业务费专项基金(No.2021QN017,2022YB001);康宝莱冬季运动营养研究中心资助课题(No.KBL2019008)。

摘　　要：目的探讨支链氨基酸(branched-chain amino acid,BCAA)补充对一次性大强度离心运动引起的肌肉损伤的改善作用。方法选用SPF级8周龄雄性SD大鼠64只,随机分为安慰剂(PLA)组及BCAA补充(BCAA)组,每组32只。各组按运动时间点进一步分为安慰剂+运动前(PC)组、安慰剂+运动后即刻(PE)组、安慰剂+运动后6 h(PE6)组、安慰剂+运动后12 h(PE12)组、BCAA+运动前(BC)组、BCAA+运动即刻(BE)组、BCAA+运动后6 h(BE6)组、BCAA+运动后12 h(BE12)组,每组8只。BCAA补充方案:正式运动前3日,BCAA组以每天1 g/kg BW剂量灌胃BCAA,安慰剂组灌胃等体积蒸馏水。运动干预方式:在跑台上进行2 h离心运动(坡度-16°、速度16 m/min)。分别在对应时间点(运动前、运动后即刻、运动后6 h、运动后12 h)进行腹主动脉取血和腓肠肌取材,用苏木精-伊红染色法观察肌纤维超微结构,用酶联免疫吸附测定血液中3-甲基组氨酸(3-methylhistamine,3-MH)水平,用RT-qPCR法检测腓肠肌中Krüppel样因子15(Krüppel-like factor 15,KLF15)、叉头状转录因子O1(forkhead box trans-cription factor O1,FoXO1)、核因子活化B细胞κ轻链增强子(nuclear factor kappa B,NF-κB)、Atrogin-1和肌肉环状指基因1(muscle ring finger 1,MuRF1)的mRNA表达。结果(1)运动后各时间点组织形态学均出现损伤情况代表造模成功,BCAA组的形态学损伤相对恢复速度较快。(2)PE组腓肠肌中KLF15(P<0.05)、FoXO1(P<0.05)、Atrogin-1和MuRF1的mRNA表达显著高于PC组(P<0.05,P<0.01),PE12组腓肠肌中NF-κB和Atrogin-1的mRNA表达显著高于PC组(P<0.05)。PE组及BE组腓肠肌中FoXO1的mRNA含量显著高于安静时水平(P<0.05)。BE组KLF15、Atrogin-1和MuRF1的mRNA表达显著低于PE组(P<0.05,P<0.01)。且BE12组NF-κB和Atrogin-1的mRNA表达显著低于PE12组(P<0.05)。PE12组血清3-MH水平显著高于PC组(P<0.05)。结论KLF15/FoXO1及NF-κB/Atrogin-1两种不同的通路分别介导了大强度离心运动后骨骼肌蛋白分解,KLF1OBJECTIVE To explore the role of branched-chain amino acid(BCAA)supplementation on muscle damage and the regulation of Krüppel-like factor 15(KLF15)and nuclear factor kappa B(NF-κB)mediated proteolytic pathways after an acute eccentric exercise.METHODS Male SD rats were divided into placebo group(PLA)and BCAA group(BCAA)randomly,32 rats per group.Both group were then placed into subgroups:placebo and pre-exercise group(PC),placebo and immediately after exercise group(PE),placebo and 6 h after exercise group(PE6),placebo and 12 h after exercise group(PE12),BCAA and pre-exercise group(BC),BCAA and immediately after exercise group(BE),BCAA and 6 h after exercise group(BE6),BCAA and 12 h after exercise group(BE12),8 rats per group.Rats in BCAA groups were supplied with BCAA(1 g/(kg·d·BW),3 days)before the exercise day and placebo groups with equal volume of distilled water.The exercised groups performed a 2 h eccentric exercise on treadmill(16 m/min,-16°slope).Blood and gastrocnemius were collected according to the time points.RT-qPCR was used to measure the mRNA expression of KLF15,NF-κB,FoxO1,Atrogin-1 and MuRF1 in gastrocnemius.RESULTS(1)No damage was found in myocytes of BC and PC group.The process of morphological damage in BCAA group was relatively faster.(2)The mRNA expression levels of KLF15,FoXO1,Atrogin-1 and MuRF1 in PE were higher than those in PC(P<0.05,P<0.01),NF-κB and Atrogin-1 in PE12 were higher than those in PC(P<0.05).The mRNA expression levels of FoXO1 in BE were higher than those in BC(P<0.05).Compared with PE,the mRNA expression levels of KLF15,Atrogin-1 and MuRF1 in BE were lower(P<0.05,P<0.01),NF-κB and Atrogin-1 in BE12 were lower than those in PE12(P<0.05).The level of serum 3-MH in PE12 group was higher than that in PC group(P<0.05).CONCLUSION The proteolysis of skeletal muscle after high-intensity eccentric exercise is mediated by two different pathways:KLF15 and NF-κB,whose activation is time-dependent.BCAA may reduce skeletal muscle proteolysis by lowering the level of gene tra

关 键 词：运动性肌损伤 支链氨基酸 Krüppel样因子15 核因子活化B细胞κ轻链增强子 蛋白质分解 

分 类 号：R153.5[医药卫生—营养与食品卫生学]