Efeito do laser de baixa potência em doses crescentes no processo de cicatrização cutânea em ratos

• Ano de defesa: 2019
• Autor(a) principal: Oliveira, Leiny Paula de
• Orientador(a): Vulcani, Valcinir Aloísio Scalla
• Banca de defesa: Vulcani, Valcinir Aloísio Scalla, Pereira, Jonathas Xavier, Souza, Taís Andrade Dias de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Ciência Animal (EVZ)
• Departamento: Escola de Veterinária e Zootecnia - EVZ (RG)
• País: Brasil
• Palavras-chave em Português: Deposição de colágeno; Densidade de energia; Inflamação; Reparação tecidual
• Palavras-chave em Inglês: Collagen deposition; Energy density; Inflammation; Tissue repair
• Área do conhecimento CNPq: MEDICINA VETERINARIA::PATOLOGIA ANIMAL
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/9366

The wound healing is a constant challenge in the animal surgical clinic, requiring new therapeutic methods for the process to be optimized and performed properly. In this aspect, the low-level laser therapy has been studied and applied in different species, as an auxiliary tool in wound healing. However, because it is a therapy with several variables to be controlled, it is very difficult to establish ideal protocols. Objectives: To evaluate the effects of using low-level laser therapy in increasing doses or fixed in the healing of cutaneous wounds in rats. Material and Methods: 75 male rats were used, divided into three groups, the control group that received no treatment, known as GC, group treated with laser at a fixed dose of 3 J/cm2 (GLF) and treated with increasing doses 1 J/cm2 , 3 J/cm2 , 5 J/cm2 (GLV). The lesion was performed with metallic punch 9 mm diameter on the back of each animal and laser irradiated on alternate days. Macroscopic and histological analyzes were performed using HE and picrosirius red staining techniques. Results: macroscopically, all groups had complete closure of the wounds on the 19th day after the lesions. Microscopically it was observed that on days 3 and 7 after the lesion, the presence of polymorphonuclear was lower in the irradiated groups and that GLV presented the lowest mean in relation to the other groups (p <0.05). The mononuclear infiltrate was observed at all times of microscopic evaluation, being present in greater quantity in the irradiated groups. On the third day of the lesion, GLV presented a greater amount of this type of cell (p <0.05), on seventh day the infiltrate was higher in GLV (p <0.05) and, on days 10 and 14, the infiltrate decreased in all groups, with the highest mean GLF (p <0.05). From the seventh day of injury, vascular connective tissue was observed. On the 14th day, fibrovascular tissue was observed in the GC and more frequently for GLV (p <0.05). With the evaluation of angiogenesis, a greater number of GLF vessels (p ˂ 0.05) were observed on day seven post-injury. On the 21th day of injury, GC had fewer vessels than the irradiated groups (p ˂ 0.05). Conclusion: The low-level laser therapy optimized wound healing, attenuated the acute inflammation, increased local vascularization, provided the formation of more organized and larger granulation tissue collagen deposition. The energy density of 1 J/cm2 was more efficient in the first three days of the lesion, with better results in the anti-inflammatory action, whereas 3 J / cm2 showed better results on the seventh day of injury. Energy densities of 3J/cm2 and 5J/cm2 from the 14th day of injury were shown to be beneficial for tissue remodeling. In this way, this work contributes to the understanding of the application of different energy densities in relation to the different periods of the cicatrization process.