Patrocínio-Silva Tatiane Lopes, de Souza André Moreira Fogaça, Goulart Raul Loppi, Pegorari Carolina Fuirini, Oliveira Jussan Rodrigues, Fernandes Kelly, Magri Angela, Pereira Rosa Maria Rodrigues, Araki Daniel Ribeiro, Nagaoka Márcia Regina, Parizotto Nivaldo Antônio, Rennó Ana Cláudia Muniz
Department of Biotechnology, Federal University of São Carlos, Rod Washington Luis, Km 235, Monjolinho, São Carlos, São Paulo, Brazil, 13565-902.
Lasers Med Sci. 2014 Jul;29(4):1357-64. doi: 10.1007/s10103-013-1418-y. Epub 2013 Aug 29.
Diabetes mellitus (DM) leads to a decrease in bone mass and increase the risk of osteoporosis and in this context, many treatments have shown to accelerate bone metabolism. It seems that low-level laser therapy (LLLT) is able of stimulating osteoblast activity and produced increased biomechanical properties. However, its effects on bone in diabetic rats are not fully elucidated. The aim of this study was to evaluate the effects of LLLT on bone formation, immunoexpression of osteogenic factors, biomechanical properties and densitometric parameters in diabetic rats. Thirty male Wistar rats were randomly distributed into three experimental groups: control group, diabetic group, and laser-treated diabetic group. DM was induced by streptozotocin (STZ) and after 1 week laser treatment started. An 830-nm laser was used, performed for 18 sessions, during 6 weeks. At the end of the experiment, animals were euthanized and tibias and femurs were defleshed for analysis. Extensive resorptive areas as a result of osteoclasts activity were noticed in DG when compared to control. Laser-treated animals showed an increased cortical area. The immunohistochemical analysis revealed that LLLT produced an increased RUNX-2 expression compared to other groups. Similar RANK-L immunoexpression was observed for all experimental groups. In addition, laser irradiation produced a statistically increase in fracture force, bone mineral content (BMC) and bone mineral density compared to DG. The results of this study indicate that the STZ model was efficient in inducing DM 1 and producing a decrease in cortical diameter, biomechanical properties and in densitometric variables. In addition, it seems that LLLT stimulated bone metabolism, decreased resorptive areas, increased RUNX-2 expression, cortical area, fracture force, BMD, and BMC. Further studies should be developed to provide additional information concerning the mechanisms of action of laser therapy in diabetic bone in experimental and clinical trials.
糖尿病（DM）会导致骨量减少并增加骨质疏松症的风险，在这种情况下，许多治疗方法已显示可加速骨代谢。低强度激光疗法（LLLT）似乎能够刺激成骨细胞活性并产生增强的生物力学性能。然而，其对糖尿病大鼠骨骼的影响尚未完全阐明。本研究的目的是评估LLLT对糖尿病大鼠骨形成、成骨因子免疫表达、生物力学性能和骨密度参数的影响。30只雄性Wistar大鼠被随机分为三个实验组：对照组、糖尿病组和激光治疗糖尿病组。通过链脲佐菌素（STZ）诱导糖尿病，1周后开始激光治疗。使用830nm激光，在6周内进行18次照射。实验结束时，对动物实施安乐死，并去除胫骨和股骨上的肌肉进行分析。与对照组相比，糖尿病组由于破骨细胞活性出现广泛的吸收区域。激光治疗的动物皮质面积增加。免疫组织化学分析显示，与其他组相比，LLLT使RUNX-2表达增加。所有实验组的RANK-L免疫表达相似。此外，与糖尿病组相比，激光照射使骨折力、骨矿物质含量（BMC）和骨矿物质密度在统计学上增加。本研究结果表明，STZ模型在诱导糖尿病1型以及导致皮质直径、生物力学性能和骨密度变量降低方面是有效的。此外，LLLT似乎刺激了骨代谢，减少了吸收区域，增加了RUNX-2表达、皮质面积、骨折力、骨密度和骨矿物质含量。应开展进一步研究，以提供有关激光疗法在实验和临床试验中对糖尿病性骨作用机制的更多信息。
