Liu Jun, Liao Zhikang, Wang Jingkun, Xiang Hongyi, Zhu Xiyan, Che Xingping, Tang Yuqian, Xie Jingru, Mao Chengyi, Zhao Hui, Xiong Yan
Department of Orthopedics, Daping Hospital, Army Medical University, Chongqing, China.
Institute for Traffic Medicine, Daping Hospital, Army Medical University, Chongqing, China.
Front Bioeng Biotechnol. 2022 Nov 14;10:1055668. doi: 10.3389/fbioe.2022.1055668. eCollection 2022.
: Skeletal muscle impact injury occurs frequently during sports, falls, and road traffic accidents. From the reported studies on skeletal muscle injury, it is difficult to determine the injury parameters. Therefore, we developed a new model of gastrocnemius impact injury in rats with a bioimpact machine, with which the experimental operation could be conducted in feasibility from the recorded parameters. Through this novel model, we study the skeletal muscle impact injury mechanisms by combining temporal and spatial variation. The gastrocnemius of anesthetized rats was injured by a small pneumatic-driven bioimpact machine; the moving speed and impact force were determined, and the whole impact process was captured by a high-speed camera. We observed the general condition of rats and measured the changes in injured calf circumference, evaluating calf injuries using MRI, gait analysis system, and pathology at different times after the injury. The gastrocnemius was injured at an impact speed of 6.63 m/s ± 0.25 m/s and a peak force of 1,556.80 N ± 110.79 N. The gait analysis system showed that the footprint area of the RH limb decreased significantly on the first day and then increased. The calf circumference of the injured limb increased rapidly on the first day post-injury and then decreased in the next few days. MRI showed edema of subcutaneous and gastrocnemius on the first day, and the area of edema decreased over the following days. HE staining showed edema of cells, extensive hyperemia of blood vessels, and infiltration of inflammatory cells on the first day. Cell edema was alleviated day by day, but inflammatory cell infiltration was the most on the third day. TEM showed that the sarcoplasmic reticulum was dilated on the first day, the mitochondrial vacuolation was obvious on the second day, and the glycogen deposition was prominent on the fifth day. In our experiment, we developed a new and effective experimental animal model that was feasible to operate; the injured area of the gastrocnemius began to show "map-like" changes in the light microscope on the third day. Meanwhile, the gastrocnemius showed a trend of "edema-mitochondrial vacuolation-inflammatory cell aggregation" after impact injury.
骨骼肌冲击伤在运动、跌倒和道路交通事故中频繁发生。从已报道的关于骨骼肌损伤的研究来看，很难确定损伤参数。因此，我们用生物冲击机开发了一种新的大鼠腓肠肌冲击伤模型，通过记录的参数，该模型在实验操作上具有可行性。通过这个新模型，我们结合时间和空间变化来研究骨骼肌冲击伤机制。用小型气动驱动的生物冲击机损伤麻醉大鼠的腓肠肌；测定移动速度和冲击力，并用高速摄像机捕捉整个冲击过程。我们观察大鼠的一般情况，测量受伤小腿周长的变化，在损伤后的不同时间使用磁共振成像（MRI）、步态分析系统和病理学评估小腿损伤情况。腓肠肌在冲击速度为6.63 m/s±0.25 m/s和峰值力为1556.80 N±110.79 N时受到损伤。步态分析系统显示，右侧后肢的足迹面积在第一天显著减小，然后增大。受伤肢体的小腿周长在损伤后第一天迅速增加，随后几天减小。MRI显示第一天皮下和腓肠肌有水肿，随后几天水肿面积减小。苏木精-伊红（HE）染色显示第一天细胞水肿、血管广泛充血和炎性细胞浸润。细胞水肿逐日减轻，但炎性细胞浸润在第三天最为明显。透射电子显微镜（TEM）显示第一天肌浆网扩张，第二天线粒体空泡化明显，第五天糖原沉积突出。在我们的实验中，我们开发了一种新的、有效的且操作可行的实验动物模型；腓肠肌损伤区域在第三天在光学显微镜下开始呈现“地图样”变化。同时，腓肠肌在冲击伤后呈现出“水肿-线粒体空泡化-炎性细胞聚集”的趋势。
