Rodrigues Natalia C, Brunelli Roberta, Abreu Daniela C C, Fernandes Kelly, Parizotto Nivaldo A, Renno Ana C M
Departamento de Fisioterapia, Universidade Federal de São Carlos, São Carlos, SP, Brazil.
Departamento de Cirurgia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil.
Braz J Phys Ther. 2014 Sep-Oct;18(5):395-401. doi: 10.1590/bjpt-rbf.2014.0057. Epub 2014 Aug 29.
The effectiveness of low-level laser therapy in muscle regeneration is still not well known.
To investigate the effects of laser irradiation during muscle healing.
For this purpose, 63 rats were distributed to 3 groups: non-irradiated control group (CG); group irradiated at 10 J/cm(2) (G10); and group irradiated at 50 J/cm(2) (G50). Each group was divided into 3 different subgroups (n=7), and on days 7, 14 and 21 post-injury the rats were sacrificed.
Seven days post-surgery, the CG showed destroyed zones and extensive myofibrillar degeneration. For both treated groups, the necrosis area was smaller compared to the CG. On day 14 post-injury, treated groups demonstrated better tissue organization, with newly formed muscle fibers compared to the CG. On the 21(st) day, the irradiated groups showed similar patterns of tissue repair, with improved muscle structure at the site of the injury, resembling uninjured muscle tissue organization. Regarding collagen deposition, the G10 showed an increase in collagen synthesis. In the last period evaluated, both treated groups showed statistically higher values in comparison with the CG. Furthermore, laser irradiation at 10 J/cm(2) produced a down-regulation of cyclooxygenase 2 (Cox-2) immunoexpression on day 7 post-injury. Moreover, Cox-2 immunoexpression was decreased in both treated groups on day 14.
Laser therapy at both fluencies stimulated muscle repair through the formation of new muscle fiber, increase in collagen synthesis, and down-regulation of Cox-2 expression.
低强度激光疗法在肌肉再生中的有效性仍不为人所知。
研究激光照射在肌肉愈合过程中的作用。
为此，将63只大鼠分为3组：未照射对照组（CG）；以10 J/cm²照射的组（G10）；以及以50 J/cm²照射的组（G50）。每组再分为3个不同的亚组（n = 7），在损伤后第7、14和21天处死大鼠。
术后7天，CG组出现破坏区域和广泛的肌原纤维变性。与CG组相比，两个治疗组的坏死面积均较小。在损伤后第14天，治疗组的组织排列更有序，与CG组相比有新形成的肌纤维。在第21天，照射组显示出相似的组织修复模式，损伤部位的肌肉结构得到改善，类似于未损伤的肌肉组织结构。关于胶原蛋白沉积，G10组胶原蛋白合成增加。在评估的最后阶段，两个治疗组的值与CG组相比在统计学上均更高。此外，在损伤后第7天，10 J/cm²的激光照射使环氧合酶2（Cox - 2）免疫表达下调。此外，在第14天，两个治疗组的Cox - 2免疫表达均降低。
两种能量密度的激光疗法均通过新肌纤维的形成、胶原蛋白合成增加以及Cox - 2表达下调来刺激肌肉修复。
