肌球蛋白重链II_xmRNA表达可能为大鼠比目鱼肌废用的分子标志  

Expression of Myosin Heavy Chain II_x mRNA as a Molecular Marker of Disuse of Soleus Muscle in Rats.

作　　者：王云英[1] 余志斌[1] 谢满江[1] 冯汉忠[1] 高放[1] 

机构地区：[1]第四军医大学航空航天生理学教研室,陕西西安710032

出　　处：《航天医学与医学工程》2002年第4期260-264,共5页Space Medicine & Medical Engineering

基　　金：高等学校骨干教师资助计划项目资助

摘　　要：目的建立大鼠跟腱切断模型 ,观测并比较跟腱切断与尾部悬吊大鼠比目鱼肌重量与肌球蛋白重链 (MHC)异构体mRNA表达的变化 ,为探讨骨骼肌废用性萎缩的机理提供实验线索。方法选取雄性SD大鼠 30只 ,随机分为 6组 ,每组 5只。直接切断跟腱 ,称量肌腱切断后第 1、3、7、1 4、2 1、2 8天比目鱼肌 (SOL)、腓肠肌内外侧头 (MG ,LG)与跖肌 (PL)的湿重。用RT PCR法观测SOLMHC异构体mR NA的表达。结果跟腱切断后第 3天 ,SOL出现明显萎缩 ,在第 7与 1 4天萎缩达最低点 ,从第 2 1天开始 ,萎缩的SOL重量有所恢复。MG、LG与PL重量的变化趋势与SOL基本一致。在正常SOL中 ,仅有MHCI与IIa mRNA表达。从跟腱切断的第 3天开始直至第 2 8天 ,SOL中出现MHCIIx mRNA的表达 ,但无MHCIIb 的表达。结论跟腱切断引起的SOL萎缩在出现时间与程度上 ,与尾部悬吊相似。两种模型均可引起SOL中MHCIIx mRNA表达 ,推测MHCIIxObjective To make an Achilles tenotomy rat model to observe the change in soleus weight and expression of myosin heavy chain (MHC) isoform mRNA, and to find some clues for elucidating the mechanisms of soleus disuse. Method Thirty male Sprangue Dawley rats were divided into 6 groups. On the 1st, 3rd, 7th, 14th, 21st and 28th days after Achilles tenotomy, wet weight of soleus(SOL), plantaris(PL), gastrocnemius mediales(MG), and gastrocnemius lateral(LG) muscles were measured. Expression of MHC II x mRNA was observed by means of reverse transcriptase polymerase chain reaction (RT PCR). Result Wet weight of SOL, MG, LG, and PL decreased significantly on the 3rd day after the tenotomy. The wet weight of these muscles reduced to the minimum on the 7th or 14th days after the tenotomy, and then recovered slightly on the 21st day after the tenotomy. There was only the expression of MHC I and MHC II a mRNA in normal soleus muscle, but no MHC II x or MHC II b mRNA. The expression of MHC II x mRNA occurred in SOL on the 3rd day after tenotomy and still expressed on the 28th day after tenotomy. There was no expression of MHC II b mRNA in SOL after Achilles tenotomy. Conclusion The appearance of atrophy of rat soleus induced by Achilles tenotomy is similar in time and extent with that induced by tail suspension. The expression of MHC II x mRNA is shown in rat soleus muscles in Achilles tenotomy and tail suspension models. The study suggests that expression of MHC II x mRNA may be used as a molecular marker of soleus muscle disuse in rats.

关 键 词：肌球蛋白 重链Ⅱx mRNA 大鼠 比目鱼肌 基因表达 跟腱切断 异构体 

分 类 号：R852.22[医药卫生—航空、航天与航海医学] R854[医药卫生—临床医学]