模拟失重影响大鼠比目鱼肌梭内外肌纤维肌球蛋白重链的表达  

The Effect of Simulated Weightlessness on Expression of Myosin Heavy Chain in Intrafusal and Extrafusal Fibers of Rat Soleus Muscle

作　　者：周继斌[1] 邢东琦[2] 冯鉴强[1] 樊小力[2] 

机构地区：[1]中山医科大学生理学教研室,广东广州510089 [2]西安交通大学医学院,陕西西安710061

出　　处：《中山医科大学学报》2002年第1期33-36,I003,共5页Academic Journal of Sun Yat-sen University of Medical Sciences

基　　金：陕西省自然科学基金资助项目 ( 98sm5 5 );广东省自然科学基金资助项目 ( 0 0 132 2 )

摘　　要：【目的】探讨模拟失重条件下大鼠比目鱼肌梭外肌纤维和梭内肌纤维肌球蛋白重链表达的变化。【方法】采用免疫组织化学技术 ,检测模拟失重条件下大鼠比目鱼肌梭内肌纤维及梭外外肌纤维对单克隆抗体NOQ7.5 .4.D和MY32的免疫反应性。【结果】经历模拟失重的大鼠比目鱼肌Ⅰ型纤维 (对NOQ7.5 .4.D呈阳性反应 )的构成比减少 ,Ⅱ型纤维 (对抗体MY32呈阳性反应 )的构成比增加。模拟失重 3d ,7d ,14d ,30d组Ⅰ型肌纤维分别占 86 96 % ,84 91% (P <0 0 1) ,6 9 14%(P <0 0 1) ,6 6 0 7% (P <0 0 1) ;Ⅱ型纤维分别占 16 14% ,18 2 1% (P <0 0 1) ,31 0 8% (P <0 0 1) ,32 15 % (P <0 0 1)。核袋纤维对NOQ7.5 .4.D的免疫反应性增强 ,核链纤维无改变 ,呈阴性反应 ;核袋纤维对MY32的免疫反应性减弱 ,核链纤维对MY32的反应增强。【结论】模拟失重除影响肌梭外肌纤维MHC的表达、引起肌纤维类型转换外 ,还导致梭内肌纤维MHC表达表型发生改变。To explore the effects of simulated weightlessness on the expression of myosin heavy chain (MHC) in intrafusal and extrafusal fibers of rat soleus muscle. Using immunohistochemical technique, immunoreactivities to two monoclonal antibodies (NOQ7.5.4.D and MY32) in intrafusal and extrafusal fibers were detected in rat undergoing the simulated weightlessness. Constituent ratios of type Ⅰ fiber (fiber positively reacted with NOQ7.5.4.D) of rat soleus muscle after simulated weightlessness decreased, while constituent ratios of type Ⅱ fiber (fiber positively reacted with MY32) increased. The constituent ratios of type Ⅰ fiber in the soleus muscle were respectively 86 96%, 84 91%(P<0 01), 69 14%(P<0 01),66 07%(P<0 01) and the type Ⅱ fiber's were respectively 16 14%, 18 21%(P<0 01), 31 08%(P<0 01), 32 15%(P<0 01) after simulated weightlessness for 3 d, 7 d, 14 d and 30 d respectively. The nuclear bag intrafusal fibers exhibited higher immunoreactivities to NOQ7.5.4.D, while the nuclear chain intrafusal fibers showed negative reaction to NOQ7.5.4.D. Nuclear bag fibers stained with less intensity in sections reacting with MY32, whereas nuclear chain fibers showed more intensity. [Conclusion] The simulated weightlessness not only results in changes in expression of MHC in extrafusal fibers and transformation of myofiber type, but also changes in expression of MHC in intrafusal fibers.

关 键 词：模拟失重 比目鱼肌 梭内肌纤维 肌球蛋白重链 大鼠 

分 类 号：R852.22[医药卫生—航空、航天与航海医学]