去神经支配后大鼠环杓后肌不同类型肌纤维的mRNA表达

The mRNA Expression of Different Muscle Fibre Types in Denervated Rat Musculus Cricoarytenoideus Posterior

目的研究去神经支配后大鼠环杓后肌不同类型肌纤维蛋白mRNA表达的变化。方法以切除单侧喉返神经后40天的8只大鼠的环杓后肌作为研究对象,使用实时定量PCR方法测定环杓后肌胶原III、肌纤维蛋白各亚型的mRNA表达,并与正常对照组相比较。结果去神经支配40天的大鼠环杓后肌,各亚型纤维蛋白的重链mRNA表达与正常对照组比较差异无统计学意义,但是I/IIB亚型纤维蛋白的mRNA表达的比值与对照组比较差异有统计学意义(P=0.018)。结论大鼠去神经支配40天时大鼠环杓后肌重链肌动蛋白I/IIB亚型纤维mRNA表达的比值增加,提示该肌肉的收缩力有减弱的趋势。

Objective To investigate the expression of the mRNA of muscle fibre types in the denervated post crieoarytenoid（PCA） muscle of rat. Methods Unilateral recurrent laryngeal nerve of eight rats were removed. Eight rats were used as controls. The mRNA expression of heavy chain myosin of PCA muscle fibre subtypes was measured with real-time quantitative RT-PCR in control rats and denervated rats 40 days after denervation. Results Compared to the control group, there were no significantly differences in mRNA expression of each muscle subtype between two groups. The ratio of MyHC type Ⅰ to lib was increased significantly（P=0. 018）. Conclusion The increased ratio of MyHC subtype Ⅰ to ⅡB suggests the decreased contraction power of denervated PCA muscle.