Exercise-induced prevention of chronicity of muscle pain: involvement of neuroimmune mechanisms

Abstract

Chronic musculoskeletal pain are a world health problem with high socio-economic impact. Currently, several mechanisms are known that modulate acute muscle pain. However, the mechanisms underlying transition of acute to chronic pain, as well as, the chronicity of pain, are poorly understood. The pharmacological approach is not necessarily efficient to control chronic muscle pain. This is because some patients do not respond to analgesics or anti-inflammatory drugs, also because there are many side effects. In contrast, physical exercise has been pointed as an efficient therapeutic to control chronic muscle pain without side effects. Our pilot-experiments showed that exercise reduces acute muscle pain and prevent it´s chronification. Considering that inflammatory signaling involves neuronal and immunological mechanisms, the aim of this study is to analyze neuroimmune mechanisms underlying exercise-induced prevention of chronicity of muscle pain. Specifically, our immune focus will be immunological cells related to inflammatory signaling, as macrophages, via activation of PPAR-gamma receptors. Our neuronal focus will be nociceptive primary afferent fibers, via activation of P2X3 receptors. To this end, a model of transition of acute to chronic muscle pain, exercise by swimming, pharmacological behavioral and molecular biology techniques will be used. (AU)