Efeitos da laserterapia de baixa intensidade na modulação de mediadores inflamatórios e receptores de bradicinina em um modelo experimental de osteoartrite

Abstract

Osteoarthritis (OA) is a degenerative joint disease characterized by inflammation, pain and stiffness in the joints are the most common symptoms. This work aims to analyze the effects of LLLT on the proinflammatory cytokines and receptors of bradykinin B1 and B2, as well as evaluating the mechanical hyperalgesia in a model of osteoarthritis induced by papain in rat knees. 54 rats were used Wistar, males, aged approximately 90 days and body weight 200 ± 50 g. The animals were divided randomly into three groups: control group, OA group without treatment and laser OA Group. The OA groups untreated and laser OA group were divided into three subgroups (6 h, 24 h and 48 h). Induction of 4% papain was held on the first, fourth and seventh day in OA groups untreated and laser OA, trial periods were counted from the last induction; the laser OA group received treatment after the last induction, and 48 h subgroup also received a second irradiation respectively to their trial period. The evaluation of mechanical hyperalgesia was conducted in the experimental periods through analgesymeter Von Frey, and at the end of each period, the animals were euthanized for obtaining washed articular and articular cartilage. They were made of gene expression by RT / PCR B1 and B2 by ELISA and protein expression of pro-inflammatory cytokines and receptors B1, B2 bradykinin. The data were tabulated and analyzed statistically using the Shapiro-Wilk test. The distribution was normal, therefore use two-way ANOVA with post hoc Bonferroni test for comparisons between experimental periods 6 h, 24 h and 48 h within each grupo.Os results of our study on the assessment of hyperalgesia, showed that the treated groups with LLLT had a reduction of hyperalgesia, with significant difference (p <0.001) compared to OA group without treatment. In the evaluation of protein expression, there was a reduction of TNF-a and CINC-1 that showed a significant difference (p <0.001, p <0.05, p <0.01) compared to the experimental periods OA group without treatment. In the evaluation of gene expression and protein B1 and B2, a reduction which showed a significant difference (p <0.001, p <0.01) compared to the experimental periods OA group without treatment. We conclude that in our study LBI was effective at modulating cytokines and decrease protein expression and gene B1 and B2 bradykinin and reduction of hyperalgesia in the treated groups.