不同运动方式对大鼠骨骼肌急性拉伤修复过程中MHC-Ⅱ,COL-Ⅰ、COL-Ⅲ的影响

Effects of Different Exercise Modes on the MHC-Ⅱ,COL-Ⅰand COL-Ⅲ in Healing Process of Acute Skeletal Muscle Injury of Rats

目的:了解不同运动方式(离心运动、向心运动)对骨骼肌拉伤愈合过程中肌肉再生和纤维化过程的影响。方法:将120只成年雌性SD大鼠随机分为空白组(BC组,n=8)、即刻组(IM组,n=8)、第1周组(1W组,n=8)、自然愈合组(NC组,n=32)、向心运动组(CE组,n=32)、离心运动组(EE组,n=32)。造成腓肠肌急性拉伤模型1周后,对CE组、EE组分别进行为期4周的向心和离心训练。IM组造模即刻、1W组造模后7天、BC组造模后18天取材;其余各组分别在造模后第14天、第21天、第28天、第35天4个时间段,每个时间段随机选择8只大鼠取材,用免疫组化的方法检测大鼠腓肠肌Ⅱ型肌球蛋白重链(MHC-Ⅱ)及Ⅰ、Ⅲ型胶原(COL-Ⅰ和COL-Ⅲ)水平。结果:损伤恢复的各个阶段,CE组MHC-Ⅱ水平较NH组和EE组高,并且恢复速度较快,而COL-Ⅰ和COL-Ⅲ水平较NH组和EE组低;EE组MHC-Ⅱ水平较NH组和CE组低,COL-Ⅰ水平较NH组低但高于CE组;COL-Ⅲ水平高于CE组和NH组。结论:不同运动方式对骨骼肌急性损伤后的修复过程影响不同,向心运动能有效促进损伤骨骼肌MHC-Ⅱ合成,从而加快骨骼肌再生,离心运动对MHC-Ⅱ合成的影响不明显。运动通过减少COL-Ⅰ表达和合成来抑制骨骼肌的纤维化,向心运动作用比离心运动更加明显。在损伤修复早期,COL-Ⅲ水平提高,使骨骼肌具备一定的强度和力学稳定性,有利于损伤后功能的快速代偿,而后期COL-Ⅲ水平持续增高可能促进和延长骨骼肌的纤维化过程。

Purpose To investigate the effect of eccentric and concentric exercises on the fibrosis and the regeneration in acute skeletal muscle sprain healing process.Methods One hundred and twenty adult female SD rats were divided randomly into 6 groups：blank control group（BC,n = 8）,immediate after acute sprain group（IM,n = 8）,first week after acute sprain group（1W,n = 8）,natural-healing group（NH,n = 32）,concentric-exercise group（CE,n = 32）and eccentric-exercise group（EE,n = 32）.One week after the acute muscle sprain,the CE group and EE group were respectively carried on concentric exercise and eccentric exercise for a total of 4 weeks.Gastrocnemius in IM group,1W group,and BC group was drawn immediate,7 days and 18 days after the acute muscle sprain,and in the others was drawn 14 days,21 days,28 days and 35 days after the acute muscle sprain,respectively.The MHC-II（myosin heavy chain-II）,and collagen type I（COL-Ⅰ）and type III（COL-Ⅲ）were detected through immunohistochemistry.Results The concentric exercise accelerated the synthesis of MHC-Ⅱ and the eccentric exercise accelerated the synthesis of COL-Ⅲ in the whole process of healing,especially in early stage;both of the eccentric and concentric exercise decreased COL-Ⅰ.Conclusion The concentric exercise promotes and accelerates the regeneration process by increasing the MHC-Ⅱ;and both of them inhibit the fibrosis process,especially the concentric exercise.Eccentric exercises endows the injured muscle with better strength and mechanical stability in early stage and promotes the fibrosis process in the later stage of the healing process by increasing COL-Ⅲ.