Liu Hong-Yu, Yang Kun, Guo Yuan, Potenza Marc N, Zhao Yan
Institute of Sport and Exercise Medicine, School of Sports Science, North University of China, Taiyuan.
Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, Xi'an.
Yale J Biol Med. 2017 Mar 29;90(1):5-13. eCollection 2017 Mar.
Drug discovery for pain management is an important area of research given current limitations in medications for pain, including the addictive potential of opiates. While exercise may help worsen or lessen pain, the precise molecular mechanisms involved are incompletely understood. Thus, in the present study, we evaluated the effects of exercise intensity on pain via assessment of behavior and c-Fos expression. An animal model of moderate and high-intensity treadmill exercise was established. The specific nociceptive behaviors, such as flinches, favoring, lifting, and licking, were observed within 60 min following intraplantar injection of formalin. Lifting and licking times in the 1 h following formalin injection were shorter in the moderate/high-intensity exercise groups than the control group. The common pain scores in the exercise groups were significantly lower than those in the control group. There was no significant difference between the exercise groups. There was no significant difference in flinches among the three groups. Moderate/high-intensity exercise decreased c-Fos expression in the ipsilateral dorsal horn. These results suggest that different intensities of exercise may substantially influence pain-related responses. Exercise may reduce c-Fos expression and attenuate pain-related behaviors and provide insight into how exercise may reduce pain. Further research is needed to understand the precise mechanisms by which exercise may reduce c-Fos expression as the mediating entities may represent suitable targets for medication development for pain management, including medications that might be used in lieu of or in conjunction with exercise.
鉴于目前疼痛药物存在局限性，包括阿片类药物的成瘾潜力，疼痛管理的药物研发是一个重要的研究领域。虽然运动可能有助于减轻或加重疼痛，但其中确切的分子机制尚未完全了解。因此，在本研究中，我们通过评估行为和c-Fos表达来评估运动强度对疼痛的影响。建立了中高强度跑步机运动的动物模型。在足底注射福尔马林后60分钟内观察特定的伤害性反应行为，如退缩、偏向、抬腿和舔舐。福尔马林注射后1小时内，中/高强度运动组的抬腿和舔舐时间比对照组短。运动组的疼痛评分显著低于对照组。运动组之间无显著差异。三组之间的退缩反应无显著差异。中/高强度运动降低了同侧背角的c-Fos表达。这些结果表明，不同强度的运动可能会显著影响与疼痛相关的反应。运动可能会降低c-Fos表达并减轻与疼痛相关的行为，并为运动如何减轻疼痛提供见解。需要进一步研究以了解运动降低c-Fos表达的确切机制，因为介导实体可能代表疼痛管理药物研发的合适靶点，包括可替代运动或与运动联合使用的药物。
