Feng Rui, Ma Xinlong, Ma Jianxiong, Jia Haobo, Ma Baoyi, Xu Liyan, Liu Aifeng
Biomechanics Labs of Orthopaedics Research Institute, Tianjin Hospital Heping Branch, 122 Munan Street, Heping District, Tianjin, 300050, China.
Tianjin Medical University, No. 22 Qixiangtai Street, Heping District, Tianjin, 300052, China.
J Orthop Res. 2015 Oct;33(10):1424-32. doi: 10.1002/jor.22796. Epub 2015 Jul 31.
Distraction osteogenesis (DO) is used to form new bone between bone segments to lengthen the callus. Skeletal muscles frequently fail to adapt to distraction, which causes complications. Insulin-like growth factor-1 (IGF-1) has been implicated as a central regulator of muscle repair. We hypothesized that IGF-1 injection could reduce muscle complications in DO. A total of 102 Sprague-Dawley rats received DO or did not were randomly assigned into saline, IGF-1 and normal groups. On the day before the distraction, the rats in the IGF-1 group were injected with IGF-1. The gastrocnemius muscles of the rats were harvested at the 0, 1st, 4th, 7th, and 10th days of distraction. The weight of the muscles, cross-sectional area (CSA) of the muscle fibers, collagen volume fraction (CVF), maximum limit load (MLL), maximum contraction forces, and gene expression of Akt, MyoD, myogenin, myostatin, and collagen I were analyzed. The results indicated that IGF-1 injection had increased the weights, CSA of the muscle fibers, MLL and force generation of the gastrocnemius. Also, Akt, MyoD, and myogenin were upregulated, and myostatin was downregulated in the IGF-1 group. Injection of IGF-1 could attenuate the gastrocnemius atrophy, prevent fibrosis, increase MLL, and regulate the related mRNA.
牵张成骨术（DO）用于在骨段之间形成新骨以延长骨痂。骨骼肌常常无法适应牵张，从而引发并发症。胰岛素样生长因子-1（IGF-1）被认为是肌肉修复的核心调节因子。我们假设注射IGF-1可以减少DO中的肌肉并发症。总共102只Sprague-Dawley大鼠被随机分为生理盐水组、IGF-1组和正常组，其中部分大鼠接受DO，部分不接受。在牵张前一天，给IGF-1组的大鼠注射IGF-1。在牵张的第0、1、4、7和10天收获大鼠的腓肠肌。分析肌肉重量、肌纤维横截面积（CSA）、胶原体积分数（CVF）、最大极限负荷（MLL）、最大收缩力以及Akt、MyoD、肌细胞生成素、肌肉生长抑制素和I型胶原的基因表达。结果表明，注射IGF-1增加了腓肠肌的重量、肌纤维CSA、MLL和力量产生。此外，IGF-1组中Akt、MyoD和肌细胞生成素上调，肌肉生长抑制素下调。注射IGF-1可减轻腓肠肌萎缩，预防纤维化，增加MLL，并调节相关mRNA。
