Avaliação da eficácia do laser de baixa intensidade sobre alterações induzidas pelo veneno da serpente Bothrops jararaca na microcirculação do músculo cremaster de camundongos

Abstract

The local reaction is a common characteristic of envenoming caused by Bothrops snakes, which depending on the extent can determine the loss of the affected limb. The antivenom therapy, which is the treatment used in the case of Bothrops snakes accidents, does not effective neutralize the local effects caused by these venoms. Thus, it is important to search for adjuvant therapies to antivenom treatment in the evolution of the local effect. Therefore, the aim of this study was to evaluate the effect of low level laser (LLL) on alterations induced by B. jararaca venom (Bjv) on mice microcirculation. For this, the animals were anesthetized and Bjv was applied topically (1 μg/20 μL) on cremaster muscle and evaluated for 10, 20 and 30 min or injected (1 μg/100 μL) subcutaneously into the cremaster muscle and evaluated at 2 or 24 h after the application of Bjv and treatment with LLL. Changes in vessel diameters were evaluated in addition to the parameters of leukocyte-endothelium interactions. The laser was applied at a wavelength of 685 nm, energy density of 7 J/cm2, 35 mW power with irradiation time of 60 sec and area of 0.3 cm2. The results showed that in the animals in which the venom was applied topically and irradiated with LBI there was a decrease in leukocyte rolling, similar to those in the non-envenomed control group. In the group that the injection of VBj was applied in the microcirculation and analyzed 2 hours later, the irradiation with the LBI caused a significant decrease of these leukocytes in rolling, adhesion and transmigration. To assess vascular reactivity, Bjv was applied topically and caused vasodilation in post-capillary venules, in the group in which the laser was irradiated immediately after the application of Bjv, we observed vasoconstriction of the venules. The results obtained in this work demonstrate that LLL, in the parameters used, presented anti-inflammatory effect by reducing the leukocyte-endothelium interaction, possibly interfering in the activation of adhesion molecules responsible for the recruitment of inflammatory cells.