单侧电刺激训练对双侧同源肌肉生长因子mRNA表达的影响

The growth factors expressing of the homologous muscle by unilateral electrical stimulating

目的:观察单侧电刺激训练对双侧同源肌肉生长因子表达的影响,探讨电刺激促进肌肉生长修复和对侧交叉迁移现象的机制。方法:SD大鼠30只,随机分为5组,每组6只,分别为对照组和1、2、3、4周电刺激组,刺激部位为右侧腓肠肌,实时荧光定量PCR法分别检测双下肢腓肠肌和前肢肱二头肌的胰岛素样生长因子-1(IGF-1)不同变构体肝型胰岛素样生长因子(IGF-1Ea)和机械力生长因子(MGF)以及成肌分化因子(Myogenin,MyoG)mRNA表达。结果:训练侧各电刺激组MGF mRNA表达较对照组分别增长了3.97、4.05、4.13、4.25倍;IGF-1Ea mRNA表达较对照组分别增长了1.55、3.99、5.11、5.27倍;MyoG mRNA表达较对照组分别增长了2.14、2.48、2.99、3.02倍,与对照组相比差异有显著性(P<0.01),而MGF和MyoG mRNA表达在各训练组之间无显著性差异(P>0.05);IGF-1Ea mRNA表达在1、2、3周训练组间有显著差异(P<0.01),第4周与第3周间无显著性差异(P>0.05);对侧同源肌肉和前肢肱二头肌IGF-1Ea、MGF、MyoG mRNA表达与对照组相比无显著性变化。结论:电刺激训练促进肌肉生长与修复机制中肌肉生长因子高表达可能起着重要作用;而对侧肌肉生长因子无显著性增长,表明对侧交叉迁移现象的机制可能不是由于肌肉生长因子表达所致,提示内分泌机制不占主导地位。

Objective： Through investigating the effects of electrical stimulation on expression of growth factors in homologous muscle, to discuss mechanism of electrical stimulating promoting the skeletal muscle growing and cross education. Method： Thirty SD rats were randomly divided into five groups：control,1 week,2 week,3 week and 4 week and stimulating the right triceps surae was stimulated by electrical stimulator. Using real-time quantitative PCR measurement to measure two alternative splices of IGF-1 （IGF-1Ea and MGF） and MyoG mRNA expressing of gastrocnemius and right biceps brachii. Result： IGF -1Ea mRNA expression of muscle was increased 1.55,3.99,5.11,5.27 fold respectively, and from first week to third week, IGF-1Ea mRNA expressing consecutively kept increased, but compared with the third week, there was no increasing at the fourth week. MGF mRNA of muscles increased 3.97,4.05,4.13,4.24 fold respectively and MyoG increased 2.14, 2.48, 2.99, 3.02 fold respectively, there was no significant increase from 1-4weeks. However in the eontralateral hind limb and forelimb skeletal muscles, the growth factors were no statistical significance. Conclusion： The processing of long-time electrical stimulation promote muscle function, the growth facts were playing a key role in the process of muscle regeneration and repairment;However no significant effects of electrical stimulation on the expression of these regulatory factors were observed in the non-stimulated contralateral hind limb and forelimb muscles, indicating that the expression of these regulatory factors was caused by direct electrical-mechanical stimulation, while the neuralendocrine might not play a main role in it.