废用条件下大鼠和达乌尔黄鼠骨骼肌氧化应激和抗氧化防御能力与肌萎缩的比较研究  

Comparative Study on Oxidative Stress and Antioxidant Defense in Skeletal Muscles of Rats and Daurian Ground Squirrels Under the Disuse Conditions

作　　者：魏艳红 张洁 高云芳 WEI Yan-Hong;ZHANG Jie;GAO Yun-Fang(The School of Basic Medical Sciences,Ningxia Medical University,Yinchuan 750004;The School of Forensic Medicine,Shanxi Medical University,Taiyuan 030001;The College of Life Sciences,Northwest University,Shaanxi Key Laboratory for Animal Conservation,Xi'an 710069,China)

机构地区：[1]宁夏医科大学基础医学院,银川750004 [2]山西医科大学法医学院,太原030001 [3]西北大学生命科学学院陕西省秦岭珍稀濒危动物保育重点实验室,西安710069

出　　处：《动物学杂志》2023年第3期420-441,共22页Chinese Journal of Zoology

基　　金：宁夏自然科学基金项目(No.2022AAC03157);宁夏医科大学特殊人才项目(No.XT2019006)。

摘　　要：本研究采用免疫荧光组织化学染色法和蛋白免疫印迹法比较研究了后肢去负荷大鼠(Rattus norvegicus)和冬眠不活动达乌尔黄鼠(Spermophilus dauricus)不同类型骨骼肌氧化应激水平和抗氧化防御能力及与肌萎缩之间的关系。结果显示,后肢去负荷14d后,大鼠比目鱼肌和趾长伸肌肌萎缩程度显著升高,过氧化氢和丙二醛水平增加,Nrf2介导的抗氧化信号通路及下游抗氧化酶蛋白表达及活性显著下降;而冬眠不活动达乌尔黄鼠骨骼肌中肌萎缩指标并未出现变化,氧化应激水平维持夏季组水平,抗氧化酶和调控因子出现不同程度升高。研究表明,后肢去负荷导致非冬眠大鼠骨骼肌氧化应激水平升高,抗氧化防御能力减弱,可能是导致大鼠废用性肌萎缩的重要机制之一;而冬眠动物达乌尔黄鼠骨骼肌在自然废用状态下,抗氧化防御能力增强可能是防止自然冬眠不活动引起的废用性肌萎缩的重要机制。[Objectives]Research on oxidative stress in skeletal muscle under disuse conditions is a topic of increasing concern among physiologists.In view of the important role of elevated oxidative stress in the development of disuse muscle atrophy,we hypothesized that hibernators and non-hibernators may exhibit differences in oxidative stress levels and antioxidant defense regulation,thus constituting intrinsic differences in the mechanism of muscle atrophy.Moreover,because of the variations in their energy metabolism and function,differences should also exist in the degree of atrophy and level of oxidative stress in different skeletal muscles.For this reason,we investigated the degree of atrophy in the SOL(slow-twitch)and EDL(fast-twitch)muscles in parallel with the level of oxidative stress,antioxidant defense and underlying mechanism in non-hibernators(Rats,Rattus norvegicus)and hibernators(Daurian Ground Squirrels,Spermophilus dauricus)between artificial and natural disuse.[Methods]We examined changes in muscle wet weight and muscle-to-body weight ratio by electronic balance.Immunofluorescence staining was performed to measure the muscle fiber cross-sectional area(CSA)and fiber type composition.Using a hydrogen peroxide(H2O2)assay kit and malondialdehyde(MDA)assay kit,we measured the concentrations of H2O2and MDA(level of oxidative stress)in muscle samples.The antioxidant activity was ascertained using specific superoxide dismutase(SOD),catalase(CAT),and glutathione peroxidase(GPx)assay kits.We detected protein expression of the Nrf2/Keap1 signaling pathway and downstream antioxidant enzymes(SOD1,SOD2,CAT,and GPx)in hindlimb loading(HU)Rats and hibernating Daurian Ground Squirrels.Differences in body weight between HU and control Rats and between hibernating inactive(HIB)and summer active(SA)Ground Squirrels were evaluated with an independent samples t-test.Muscle wet weight,ratio of muscle wet weight/body weight,fiber-type distribution,fiber CSA,and all the protein expression levels were analyzed using two-way ANOVA

关 键 词：后肢去负荷 冬眠 氧化应激 抗氧化防御 骨骼肌 

分 类 号：Q955[生物学—动物学]