【作者】 向峥；

【导师】 余斌；

【作者基本信息】 第一军医大学 ， 骨外科， 2004， 硕士

【摘要】 研究背景：在日常的体育锻炼及军事训练中，适应与损伤是两个并存的重要方面，训练结果如何取决于两者的平衡状态。目前国内骨骼肌运动损伤的研究比较少，主要集中在运动对骨骼肌超微结构、生化及酶学等方面的影响，国外在细胞因子在运动性肌损伤中的表达也处于起步阶段。骨骼肌损伤后的再生，伴随着复杂的生物学调节机制，与大量的细胞因子相关。其中IGF参与骨骼肌损伤修复过程中的细胞增殖和分化，IGF-Ⅰ主要促进骨骼肌的增值，IGF-Ⅱ主要对增殖后的细胞分化产生作用；bFGF是调控骨骼肌胚胎发生与生长发育的主要生长因子。细胞凋亡是骨骼肌损伤后细胞发生坏死过程中的重要作用因素，如凋亡相关基因：Bcl-2、Bax等在骨骼肌细胞凋亡过程中起着非常重要的作用。 目的：通过研究胰岛素样生长因子-Ⅰ(IGF-Ⅰ)对骨骼肌运动损伤后卫星细胞再生的影响，探讨IGF-Ⅰ在骨骼肌运动损伤修复中的应用前景。 方法：使用SD大鼠1周力竭模型，首次力竭后第1、3、5天给予右侧腓肠肌中部的肌膜下分别注射外源性IGF-Ⅰ 300mg／ml(实验组)、生理盐水1ml(对照组)，分别在首次力竭后第7、9、11、17、24、30天取材，进行骨骼肌HE染色光镜观察，电镜超微结构观察和增殖细胞核抗原(PCNA)表达比较。 结果：HE染色光镜观察：首次力竭后第7天，腓肠肌局部充血、水肿、部分纤维断裂，炎性细胞浸润，聚集于肌损伤处(图4、5)。第11天，对照组(一周力竭训练+生理盐水组 C组)损伤处有大量的成纤维细胞出现，细胞核排列充紊乱;实验组(一周力竭训练+I GF一I组D组)有大量新生的肌管和肌纤维细胞，细胞核数目非常多，肌管的细胞核位于细胞中央，肌纤维的细胞核位于细胞边缘(图6，7)。第17天，对照组(一周力竭训练+生理盐水组C组)有较多胶原纤维，排列紊乱;实验组(一周力竭训练+I GF一工组D组)新生肌细胞排列成串珠样，较整齐(图8，9)。第30天，对照组(一周力竭训练+生理盐水组C组)有胶原纤维瘫痕形成;实验组(一周力竭训练+I GF一I组D组)再生较完全，基本未见纤维瘫痕(图10，11)。超微结构电镜观察:首次力竭后第7天，对照组(一周力竭训练+生理盐水组C组)可见肌浆网扩张，糖原数量增多，线粒体肿胀空腔化;实验组(一周力竭训练+I GF一I组D组)线粒体数量增多，空腔化少，肌浆网扩张少(图14，15)。首次力竭后第n天，对照组(一周力竭训练+生理盐水组C组)可见结缔组织增生，胶原纤维多;实验组(一周力竭训练+IGF一I组D组)可见新生肌纤维，卫星细胞(图16，17)。PCNA指数实验组明显高于对照组(一周力竭训练十生理盐水组C组) (P(0.05)。结论:工GF一I与骨骼肌的损伤及修复相关，IGF一I对运动性骨骼肌损伤后的卫星细胞再生有促进作用。更多还原

【Abstract】 Background The training effect lies on the equilibrium of the two facets. Presently, the domestic study of skeletal muscle exercise damage is rarely done which is mainly localized in the study of exercise effect to the ultrastructure, bio-chemistry and enzymology in the skeletal muscle. Overseas study of cell factors expression in exercise-induced skeletal muscle damage is in the initial phase.The regeneration of skeletal muscle which is followed by complicated biological regulative mechanism is relative to many cell factors. Thereinto the cell factor insulin-like growth factor(IGF) is concerned with cell proliferation and differentiation in the rehabilitation for skeletal muscle damage. IGF-I chiefly promotes the cell proliferation of skeletal muscle, while IGF-II is vital in the differentication of the proliferated skeletal muscle cells. Otherwise, basic fibroblast growth factor (bFGF) is the primary growth factor in the regulation of skeletal muscle embryogenesis, growth and development which is potent regulator in skeletal muscle proliferation and differentiation. Cell apoptosis is an important factor in the cell necrose following the skeletal muscle damage. The apoptosis relative genes such as Bcl-2, Bax are crucial in skeletal muscle cell spoptosis.Adaptation and damage are two dichotomal facets in daily physical exercise and military training.Objective To study the effect of IGF-I on the regeneration of satellite cells after sports injury, and explore the applications of IGF-Iin the field of repairof skeletal muscle after sports injury.Methods Using SD rat 1 week exhausting model, on 1,3,5th day after the first exhausting,300mg/lml IGF-I was injected into the middle of right gastrocnemius muscle of the treatment group. The control groups were injected 1ml saline. The samples were taken on the 7,9,11,17,24,30th days after the first exhausting, the skeletal muscle was dyed with HE and observed with optical microscope and electric microscope. The expression of proliferating cell nuclear antigen (PCNA) in it were compared. Results On the 7,11,17th days after the first exhausting, the satellite cells decreased significantly in the treatment group, the collagen fibres increased in the control groups. On the 30th day, the muscle fibre’s shape was in good condition for the treatment groups, but healed with scar tissue in the control groups. Observed by electric microscope, the biolast’s shape is normal, new born muscle fibre can be found in the treatment groups, expanded sarcoplasmic reticulum, increased glycogen granule, engorged biolast and apoptotic cells can be found in the control groups. The PCNA exponent of the treatment group was obviously higher than the control group.Conclusions IGF-I can accelerate the regeneration of skeletal muscle satellite cells after sports injury.更多还原