Modulação dos processos inflamatórios e da morfofisiologia periarticular promovida pelo treinamento resistido preventivo em modelo experimental de artrite reumatoide

Abstract

Introduction: Rheumatoid arthritis (RA) is a chronic, autoimmune, and systemic inflammatory disease, characterized by joint inflammation that causes progressive degradation of joint and periarticular tissues, resulting in pain, stiffness, and functional loss. Associative complementary strategies, such as resistance training, have been explored due to their potential benefits in reducing inflammation and improving patient functionality. However, protocols are applied after the onset of RA symptoms, when the inflammatory process and tissue degradation are already advanced, and little is known about their prophylactic effects. Objective: To analyze the effects of resisted stair climbing exercise (TRSE), as a prophylactic strategy to reduce the inflammatory process and morphofunctional damage in periarticular tissues, in an experimental model of RA. Methods: For this purpose, 34 Wistar rats, with an initial age of 12 weeks, were distributed into four experimental groups: control group (GC, n=9), arthritis group (GA, n=9), exercise group (GE, n=8), and exercise + arthritis group (GEA, n=8). The animals in the exercise groups underwent progressive intensity and volume TRSE for nine weeks, configuring a high-intensity protocol, and were subjected to it before the induction of RA, which was promoted through intra-articular administration of Complete Freund's Adjuvant (CFA). To measure the edema and functionality of the affected limb, five assessments were performed: joint diameter, joint disability, grip strength, nociceptive sensitivity, and motor function. The animals were euthanized in the 11th week of the experiment by a CO2 and guillotine associative method. The following was collected: synovial fluid, for leukocyte migration analysis; peritoneal lavage, for macrophage counting and function analysis; plasma and lymph node, for oxidative system enzyme analysis; the rectus femoris muscle, for histomorphometric and histopathological analyses, fiber typing, histochemistry of the Neuromuscular Junctions – NMJs, and oxidative stress biomarkers. For statistical analysis, the Generalized Linear Model (GLM) was used, through the JAMOVI Program, with a significance level of p<0.05, using post-hoc tests, Tukey, or Bonferroni adjustment. Results: The TRSE promoted the reduction of the inflammatory process, oxidative stress, histopathological index, and intramuscular connective tissue of the rectus femoris in the GEA group, when compared to the GA group. In some markers, such as TNF-α, muscular IL1-β, and plasma SOD activity, there was no difference between the GEA and GE groups. The similarity of superoxide levels, macrophage count, and lysosomal retention between the GEA and GC groups, associated with the reduction of H2O2, NO, and macrophage adhesion rate in the peritoneal lavage, suggests modulation of systemic inflammation by TRSE. However, these outcomes were not reflected in a significant improvement in the functional outcomes assessed. Conclusion: High-intensity preventive TRSE showed a limited protective effect, with a reduction in inflammatory and oxidative markers, partially preserving the morphology of the rectus femoris muscle, without significant functional repercussions.