外源性胰岛素样生长因子-2促进骨骼肌损伤修复的实验研究

Experimental Study on the Effect of Extrinsic Insulin-like Growth Factor-2 on the Healing of Skeletal Muscle Contusion

目的 :研究局部使用外源性胰岛素样生长因子 2 (Insulin-likeGrowthFactor-2 ,IGF -2 )对骨骼肌钝性打击伤后愈合速度、质量和对内源性IGF -1、IGF -2的mRNA表达的影响。方法 :对大鼠右下肢腓肠肌内侧面中段实施钝性打击伤 ,分别于损伤局部注射外源性IGF -2 (实验组 )及生理盐水(对照组) ,观察骨骼肌损伤修复情况。结果 :伤后实验组比对照组更早形成基底板层保护膜 ,更早更多地激活成肌细胞、生成肌丝、形成肌管、融合成肌纤维 ,愈合质量也较好。实验组的IGF -1mRNA含量在伤后 1、2、3、4天升高 ,IGF -2的mRNA含量在伤后 1、2、3、4、6、9、1 4天均升高 ;对照组的IGF -1mRNA含量在伤后 2、3、4、6、9、1 4天升高 ,IGF -2的mRNA含量在伤后 3、4、6、9天升高。结论 :局部注射外源性胰岛素样生长因子 -2可以使内源性的IGFmRNA表达提早 ;可以刺激成肌细胞增生 ,促进肌管形成 ,加速肌管融合成肌纤维 ,加速骨骼肌创伤后修复过程 。

Objective To investigate the effect of insulin-like growth factor-2(IGF-2)on the healing course and healing quality following skeletal muscles contusion and the expression of IGF-1 and 2 mRNA in local muscles. Results The experimental group formed basement membrane 'borders' earlier than the control group. The myoblasts,myofibrils and myotubes grew more and faster in the experimental group than the control, the myotubes fused to myofibres earlier in the experimental. The expression of intrinsic IGF-1 mRNA increased in day 1,2,3,4 after tauma, and that of IGF-2 mRNA increased in day 1,2,3,4,6,9,14 after tauma. However, in control group the expression of intrinsic IGF-1 mRNA increased in day 2,3,4,6,9,14 after tauma and IGF-2 mRNA increased in day 3,4,6,9 after tauma. Conclusions Local injection of IGF-2 could promote earlier secretion of endogenic IGF mRNA, and could stimulate the proliferation of myoblasts to hasten the formation and fusion of myotubes and accelerate the healing of skeletal muscular injury.