Efeito do laser, λ904 nm, na cicatrização por 1ª intenção no modelo experimental em ratos

Abstract

The low level laser therapy is a therapeutic resource that acts on intracellular biomodulation, decreasing the inflammatory process, reduction of interstitial liquid, increased phagocytosis, proliferation, collagen synthesis and neovascularization. Purpose: To evaluate the effect of low-level laser therapy (LLLT), λ904 nm, on wound healing by first intention on the experimental model in rats. Methods: 40 male Wistar rats were used, divided into four groups, underwent incision along the lines Alba covering skin, subcutaneous and muscle abdominal, sutured continuously for nylon 5-0. Eight and fifteen days after the surgery process, the repairing area was removed and histological sections were stained with hematoxylin-eosin to assess cellularity inflammatory, Masson´s Trichrome and Picrossirus to quantify the collagen fibers and immunohistochemical technique for counting newly formed vessels. The data were compared statistically using analysis of variance ANOVA, with a "post-hoc Tukey test, p <0,05. Results: we found that LLLT reduced the intensity of the inflammatory reaction and influenced the dynamic of the immunoinflammatory response by inducing switching of the leukocyte infiltration pattern (neutrophilic to lymphoplasmacytic infiltration). Also stimulate the deposition and enhance the organization of collagen fibers, featuring a delicate collagen type III. Furthermore, it appeared to a significant increase in the average number of newly formed vessels (p = 0.001, in G1 and G2; and p = 0.02, in G3 e G4). Conclusions: LLLT resulted in modulate of the inflammatory response, enhanced deposition of collagen fibers and increase in the average number of newly formed vessels.