负离心定量运动训练对大鼠肱三头肌损伤的程度及作用机制

Experimental study on triceps damage of rats after negative exercise

目的 研究负离心定量运动训练对大鼠肱三头肌损伤的程度，了解其发生的作用原理。方法 采用实验动物以 15 m/min的速度在－ 20°倾斜角的运动跑台上持续运动 90 min，观察各组动物运动训练后肱三头肌组织学的变化。结果 运动组肌纤维数目密度明显下降（ P< 0.01），并有肌纤维肿胀、变性坏死、炎性浸润。结论运动训练后肌纤维形态学损伤明显加重，以氧化磷酸化能力差的 FG型（Ⅱ b型）纤维为主。

Objective To know the damage degrees and mechanisms of the triceps of the rats after a fixed amount of eccentric exercise. Method A treadmill protocol was given to each of 15m/min and at－ 20° degree. Histological changes were observed after training. Result Myofibrosis, degeneration, necrosis with inflammatory cell infiltration to the tissue occurred and a decreased density of muscle fibers were observed(P< 0.01).Conclusion The negative eccentric exercise could bring about signficantly morphologic damage of the muscle.The FG fiber (Ⅱ b) with poor oxidative phosphorylation is even worse damaged.