Low-level laser therapy in periarticular morphological aspects of the knee of Wistar rats in rheumatoid arthritis model

Abstract

BACKGROUND AND OBJECTIVES: The deleterious effects of rheumatoid arthritis on periarticular tissues have not yet been fully elucidated. Therefore, the search for treatments that can modulate the inflammatory profile and tissue remodeling is pertinent. The present study evaluated the effects of low-level laser therapy (LLLT) on the morphology of periarticular tissues and synovial membrane of rats in a rheumatoid arthritis model. METHODS: Sixty-four male rats were divided into acute (7 days) and chronic (28 days) inflammatory periods, with four groups (n=8) each, being: CG (control group), LG (lesion group), CLaG (laser control group) and LLaG (laser lesion group). The animals of the lesion groups received two inoculations of Freund's Complete Adjuvant at a concentration of 50µL, the first at the base of the tail, and the second at the right knee. The animals in the control groups were injected with isotonic sodium chloride solution. The ClaG and LLaG were treated with 660nm LBI, 5J/cm 2 in the right knee. After the experimental period, the animals were euthanized, and the knees were processed for light microscopy. RESULTS: The CG and CLaG morphological analysis had normal aspects. The LG showed synovitis, femur, and tibia with changes in the periosteum, with inflammatory cells and bone modifications. In the LLaG, the synovial membrane showed signs of improvement. Bone tissue in the chronic period showed morphological aspects, denoting tissue remodeling. Low-level laser therapy in periarticular morphological aspects of the knee of Wistar rats in rheumatoid arthritis model Laser de baixa intensidade nos aspectos morfológicos periarticulares do joelho de ratos Wistar em modelo de artrite reumatoide

Photobiomodulation (λ=808nm) and Platelet-Rich Plasma (PRP) for the Treatment of Acute Rheumatoid Arthritis in Wistar Rats

“…47 Evaluating the effects of the laser in the acute phase, we observed a reduction in inflammatory areas and better tissue organization, and the literature describes better synovial organization and reorganization of adipocytes after 7 days of arthritis induction. 48 The effects of the association of PBM with a laser (λ = 810 nm and 100 mW) and PRP were observed in the reduction of pain in patients with knee inflammation in our study; the pain measurement (nociception) of the animals was not performed, but the reduction of the inflammatory process was observed. We can suggest that with less inflammatory process, lower levels of leukotrienes and prostaglandins responsible for pain during inflammation are released.…”

Therapeutic Effect of Aquatic Resistance Exercise on Rectus Femoris and Knee in a Model of Rheumatoid Arthritis

“…As for the repercussions on the knee joint, morphologic signs of degeneration of the articular cartilage and synovial membrane found on RA and EXRA were observed. The migration of synoviocytes, similar to fibroblasts, is the main pannus-forming event, which implies a severe inflammation of the synovial tissue, followed by the formation of numerous chemokines, cytokines, matrix metalloproteases that favor joint destruction (41,42). These synoviocytes present in synovial inflammation produce enzymes involved in cartilage destruction and also the receptor activator ligand nuclear factor kappa B (RANKL) that regulates the differentiation of osteoclasts that carry out bone destruction and blood vessel neoformation (34).…”