EVIDENCE THAT A PHYSICAL ACTIVITY PROTOCOL CAN REDUCE SYNOVIAL LEUKOCYTE COUNT IN ARTHRITIC RATS

Introduction: Physical activity is thought to be beneficial to arthritis, delaying disability and/or improving joint function. In vivo studies using experimental models of arthritis may provide useful information about such benefits. Objective: The aim of the present study was to evaluate the effects of the low-intensity exercise on a model of CFA-induced arthritis in rats. Methods: Articular incapacitation was measured by the paw elevation time in 1-min periods of stimulated walk. Edema was evaluated by the knee-joint diameter. Synovial exudate was sampled after 10 days for leukocyte count. The exercise protocol consisted of a 2-min period of stimulated walk in the 1st day, 10 min in the 2nd day, and 20 min from the 3rd to the 10th day; The control animals were submitted to 1-min period of stimulated walk once a day over 10 days. Corticosteroid involvement was assessed by treating the animals with aminoglutethimide. Results: The exercise protocol produced a slight but sustained reduction of disability and joint swelling associated with a large reduction in the synovial leukocyte count. Aminoglutethimide only prevented the effect on synovial leukocyte count. Conclusion: These results suggest that a low-intensity physical activity does not aggravate the symptoms of arthritic animals, in fact showing a slight improvement, and still can markedly reduce the migration of leukocytes into the synovial space.