Low-intensity laser phototherapy on acute inflammatory process

Abstract

The phototherapy with low intensity laser can bring a lot of therapeutic benefits whatever a few is known about the optimum parameters of this therapy. So, the purpose of the present study is to investigate the effects of the phototherapy on acute inflammatory process testing different protocols of irradiation. The rat paw oedema will be induced by sub-plantar injection of carrageenan and the paw volume will be measured before, and 1, 2, 3 and 4 hours after the injection using a plethysmometer. To investigate the protocols, six-hundred male mice (brown and white) will be divided into 6 groups (n=6). After 1 and 2 h of carrageenan injection, animals will be irradiated using a low-power infrared laser (l= 810nm) accordingly to energy and power applied: 1/30 (1 Joule e 30mW); 1/60 (1J e 60mW); 1/100 (1J e 100mW); 3/30 (3J e 30mW); 3/60 (3J e 60mw); 3/100 (3J e 100mW). Two more groups will be done by animals not irradiated: negative control (just rat paw oedema) and positive control (oedema plus administration of an anti-inflammatory drug- sodium diclofenac 1ml/Kg). The analyses will be made by RT-PCR technique to COX-2 e COX-1 and also will be measured oedema, PGE2, Nitrotirosin and Mieloperoxidase (MPO). The data obtained will be analyzed and the best statistic test will be done. Light attenuation in inflammed and healthy paw will also be evaluated. (AU)