Laser Therapy on Arthritis Induced by Urate Crystals

Objective: We aimed to evaluate low-power laser therapy efficacy on fibrinogen (PIT) in the plasma of rats with arthritis induced by urate crystals. In addition, anatomopathological (AP) studies were carried out. Background Data: Raised blood uric acid may form microscopic crystals in the joint. These crystals set up the inflammation called "acute gouty arthritis." Methods: Two mg of uric acid were injected in both joints of the lower limbs of rats over 2 days. A group was treated with He-Ne laser (6 mW) on the injected joints during 3 consecutive days. After 96 It of the first injection, animals were sacrificed to determine fibrinogen by spectrophotometry. Sections from the lower limbs were used for AP studies. Results: A statistically significant increase (p < 0.001) in plasma fibrinogen levels was observed in the group injected with urates, when compared to both control group and the laser-treated group. The AP observed in the untreated group showed an intense fibroblastic proliferation and chronic inflammation. In the group treated with laser no inflammatory reaction was observed. Conclusions: Laser therapy has an anti-inflammatory effect in arthropathy induced in rats injected with urates, determined by fibrinogen levels and by histological involution.