SD大鼠骨骼肌钝挫伤早期的组织病理变化

背景：骨骼肌钝挫伤后继续运动对骨骼肌组织愈合的影响目前还没有确切的定论。目的：观察急性骨骼肌钝挫伤SD大鼠跑台运动后的组织病理变化。方法：将64只SD大鼠随机分为正常对照组、模型组、自然愈合组、运动干预组,后3组建立左后肢腓肠肌中段骨骼肌钝挫伤模型,模型组造模后6 h处死取材,运动干预组进行跑台运动干预,自然愈合组继续饲养,但不进行运动干预。结果与结论：自然愈合组、运动干预组大鼠急性腓肠肌钝挫伤后24 h~3 d内损伤肌肉组织中均出现大量炎细胞浸润,5 d时显著下降,同期内各时间点运动干预组炎细胞数显著多于自然愈合组(P < 0.05);7 d时两组炎细胞基本消失,伤后5 d两组均开始出现少量瘢痕组织,随时间延长而逐渐增加,7~14 d时运动干预组瘢痕组织面积显著高于自然愈合组(P < 0.01);伤后14 d两组瘢痕组织均仍有增多趋势。表明急性骨骼肌钝挫伤后早期运动训练可加重损伤局部炎性反应,并导致瘢痕组织过度形成,对损伤骨骼肌的修复存在负面影响。

Histopathological changes of SD rat skeletal muscle in the early stage of contusion

BACKGROUND:Effects of keeping exercise after skeletal muscle contusion on regeneration of muscular tissue remain unclear.OBJECTIVE:To investigate the effects of treadmill running on the histopathology of skeletal muscle in SD rats with acute contusion.METHODS:A total of 64 male SD rats were randomly divided into four groups: normal control group, model group, natural healing group and exercise intervention group. Skeletal muscle contusion model in the middle part of the hindlimb gastrocnemius was constructed in the latter three groups. Rats in the exercise intervention group underwent treadmill exercise; rats in the natural healing group received normal feeding without exercise intervention. Rats in the model group were sacrificed at the 6th hour after model construction.RESULTS AND CONCLUSION:Massive inflammation cells were found in rat damaged muscle tissues of the natural healing group and exercise intervention group in the 24th hour to the 3rd day after acute gastrocnemius contusion injury; the inflammation decreased on the 5th day. The number of inflammation cells in the exercise intervention group was significantly larger than that in the natural healing group at different time points of the same period (P < 0.05). The inflammation cells disappeared on the 7th day after injury in both groups. A small amount of scar tissue was found on the 5th day after injury in both groups, which increased gradually with time. The area of fibrous scar in the exercise intervention group was significantly larger than that in the natural healing group on the 7th to 14th days after injury (P < 0.01); there was still a growing trend in the scar tissues of both groups on the 14th day after injury. It indicate that exercise can aggravate the local inflammation and lead to excessive formation of scar tissue in the early regeneration following acute contusion of skeletal muscle; it has a negative impact on the repair of skeletal muscle.