摘要
目的:探讨长期低频电刺激对6周龄雄性SD大鼠废用性肌萎缩的影响并初步探讨其调控机制。方法:取32只雄性6周龄SD大鼠,随机分为正常组、废用性肌萎缩组、隔日电刺激组和每日电刺激组。对照组不予任何处理。其余3组采用改良式尾部悬吊法建立大鼠废用性肌萎缩模型,即单笼饲养,尾部悬吊,前肢着地,后肢悬空,身体长轴与水平面成30°角。两电刺激组每日1次或隔日1次电刺激大鼠腓肠肌和比目鱼肌,刺激频率30 Hz,波宽200μs,每次刺激30分钟,持续30天。采用mATPase组织化学染色法观察肌纤维的转化,采用荧光实时定量PCR方法观察肌球蛋白重链I、IIa、IIx、IIb基因表达,采用Western blot方法检测MAPK相关激酶蛋白表达。采用灰度扫描仪对腓肠肌和比目鱼肌肌纤维蛋白表达进行灰度扫描。结果:电刺激30日后,隔日电刺激组和每日电刺激组大鼠腓肠肌和比目鱼肌I型肌纤维比例较废用性肌萎缩组明显升高,II型肌纤维比例较废用性肌萎缩组明显降低,且每日电刺激组效果较隔日刺激组好。每日电刺激组大鼠腓肠肌和比目鱼肌I型MHC mRNA表达较废用性萎缩组明显升高,接近正常组,且每日刺激组恢复较隔日刺激组明显,每日刺激组腓肠肌IIb型MHC mRNA表达较废用性萎缩组有显著性差异。电刺激组腓肠肌和比目鱼肌肌纤维MAPK相关激酶蛋白表达与废用性肌萎缩组相比均有明显变化。结论:长期低频电刺激可以有效改善废用性肌萎缩,这可能与JNK/MAPK通路激活相关。
Purpose This study aims at exploring the effect of long-term low frequency electrical stimulation on muscular disuse atrophy of rats. Methods 32 male SD rats, aged 6 weeks, were randomly divided into normal group （N）, atrophy group （A）, atrophy plus everyday electrical stimulation group （AS1）, and atrophy plus every other day electrical stimulation group （AS2）. Disuse atrophy rat model was established through tail suspension allowing only forelimb touchdown. Electrical stimulation was set at 30 Hz and 200 us.,and applied to gastrocnemius and soleus of groups AS1 and AS2 30 minutes per day. Myofibrillar conversion was observed by histochemical staining,genetic expression of types I, IIa, IIx, and IIb myosin heavy chain （MHC）by fluorescence real-time quantification PCR, and MAPK kinase protein expression by Western blot. Results After 30 days of electrical stimulation, the proportion of type I fiber in gastrocnemius and soleus was significantly greater and type II significantly smaller in groups AS1 and AS2,especially in groups AS1 ,than that in group A. Expression of type I fiber MHC mRNA in group AS1 was similar to that in group N and significantly higher than that in group A. Expression oftype IIb fiber MHC mRNA in group AS1 was significantly different from that in group A. The expression of MAPK related kinase protein in muscle fiber in groups AS1 and AS2 changed significantly as compared with that in group A. Conclusion Long term low frequency electrical stimulation effectively improves disuse atrophy probably due to the activation of JNK/MAPK passageway.
出处
《中国运动医学杂志》
CAS
CSCD
北大核心
2014年第1期42-46,85,共6页
Chinese Journal of Sports Medicine
关键词
废用性肌萎缩
腓肠肌
比目鱼肌
电刺激
disuse atrophy, gastrocnemius, soleus, electrical stimulation
