The basic analysis of connective tissue fibrosis after muscle strain injury

本研究的目的是研究肌肉收缩损伤对肌肉质量、功能、结构和蛋白表达的重复性影响。我们使用我们最初开发的用于大鼠腓肠肌的拉长收缩(LCS)模式的装置。结果显示，内侧和外侧的腓肠肌均明显小于对照组。LCS患者肌肉中肌生长抑素的含量显著高于对照组。此外，FOXO1和FOX03在LCS中的表达显著高于对照组。这些结果表明，在我们的模型中，反复发作的LCS导致肌肉质量和力量的下降。我们还观察了蛋白质降解信号通路的激活和肌肉生长抑素的激活，而蛋白质合成的失活。我们的结论是，LCS诱导的萎缩和扭矩不足与蛋白质降解过程的激活有关，而不是与细胞凋亡过程有关。

The purpose of this study was to investigate the repetitive effects of contraction-induced injury on muscular mass, function, structure, and protein expressions. We employed our originally developed device with lengthening contractions (LCs) mode used in rat gastrocnemius muscle. The results showed that both medial and lateral gastrocnemius muscle were significantly smaller than those in control. The muscle content of myostatin was significantly higher in LCs than in control. In addition, FOXO1 and FOXO3 showed significantly enhanced expression in LCs than in control. These results suggest that repeated bouts of LCs in our model induced decreases in muscular mass and strength. We also observed the activation of protein degradation signaling pathways and myostatin while inactivation of protein synthesis. We conclude that the LCs-induced atrophy and torque deficit are associated with activation of the protein degradation process not apotosis process.