Brunelli Roberta M, Rodrigues Natalia C, Ribeiro Daniel A, Fernandes Kelly, Magri Angela, Assis Lívia, Parizotto Nivaldo A, Cliquet Alberto, Renno Ana Claudia M, Abreu Daniela C C
Post Graduation Program of Surgery, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, Brazil.
Lasers Med Sci. 2014 Jan;29(1):91-6. doi: 10.1007/s10103-013-1277-6. Epub 2013 Feb 14.
The objective of this study was to assess the effects of 780-nm low-level laser therapy at different periods of 7, 14 and 21 days after cryolesion, including the dose (10 or 50 J/cm(2)), to promote a better muscle repair evidenced by histopathological and immunohistochemical analyses. Fifty-four male rats were divided into three groups: injured control group (CG)-injured animals without any treatment; injured 780-nm laser-treated group, at 10 J/cm(2) (G10); and injured 780-nm laser-treated group, at 50 J/cm(2) (G50). Each group was divided into three subgroups (n = 6): 7, 14 and 21 days post-injury. Histopathological findings revealed better organised muscle fibres in the G10 and G50 during the periods of 7 and 14 days compared to the CG. The G10 and G50 during the 7 days showed a significant reduction (p < 0.05) of lesion area compared to the CG, without differences between groups treated for 14 and 21 days. The G10 showed an increase of the amount of vessels after 14 days compared to the G50, but not in relation to controls. With regard to the immunohistochemical analyses of the MyoD factor, the G10 and G50 during the 7 days showed higher concentrations of immunomarkers than controls. Myogenin immunomarkers were similarly observed at days 7 and 14 in all the three groups analysed, whereas immunomarkers were found in none of the groups after 21 days of laser therapy. The results showed that laser, regardless the applied dose, has positive effects on muscle repair.
本研究的目的是评估在冷冻损伤后7天、14天和21天的不同时间段，780纳米低强度激光疗法（包括剂量为10或50 J/cm²）对促进肌肉更好修复的效果，这通过组织病理学和免疫组织化学分析得以证实。54只雄性大鼠被分为三组：损伤对照组（CG）——未接受任何治疗的损伤动物；10 J/cm²的780纳米激光治疗损伤组（G10）；以及50 J/cm²的780纳米激光治疗损伤组（G50）。每组又分为三个亚组（n = 6）：损伤后7天、14天和21天。组织病理学结果显示，与CG组相比，G10组和G50组在7天和14天期间的肌纤维组织更有序。与CG组相比，G10组和G50组在7天时损伤面积显著减小（p < 0.05），而在14天和21天治疗的组之间没有差异。与G50组相比，G10组在14天后血管数量增加，但与对照组相比无差异。关于MyoD因子的免疫组织化学分析，G10组和G50组在7天时免疫标志物浓度高于对照组。在所有分析的三组中，7天和14天时均观察到生肌调节因子免疫标志物，而在激光治疗21天后，所有组均未发现免疫标志物。结果表明，无论应用何种剂量，激光对肌肉修复都有积极作用。
