Institute of Biomedical Sciences (Health Sciences), Nagasaki University, Nagasaki, Japan.
Department of Physical Therapy Science, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
PLoS One. 2023 Aug 10;18(8):e0289765. doi: 10.1371/journal.pone.0289765. eCollection 2023.
We investigated the effect of regular walking exercise prior to knee osteoarthritis (OA) on pain and synovitis in a rat monoiodoacetic acid (MIA)-induced knee OA model. Seventy-one male Wistar rats were divided into three groups: (i) Sedentary + OA, (ii) Exercise + OA, and (iii) Sedentary + Sham groups. The Exercise + OA group underwent a regular treadmill walking exercise at 10 m/min (60 min/day, 5 days/week) for 6 weeks, followed by a 2-mg MIA injection in the right knee. The right knee joint was removed from rats in this group at the end of the 6-week exercise period and at 1 and 6 weeks after the MIA injection. After the 6 weeks of treadmill exercise but before MIA injection, there were no significant differences among the three groups in the pressure pain threshold, whereas at 1 week post-injection, the Exercise + OA group's pressure pain threshold was significantly higher than that in the Sedentary + OA group, and this difference persisted until the end of the experimental period. The histological changes in articular cartilage and subchondral bone revealed by toluidine blue staining showed no difference between the Sedentary + OA and EX + OA groups. The expression levels of interleukin (IL)-4 and IL-10 mRNA in the infrapatellar fat pad and synovium were significantly increased by the treadmill exercise. Significant reductions in the number of CD68-, CD11c-positive cells and IL-1β mRNA expression and an increase in the number of CD206-positive cells were observed at 1 week after the MIA injection in the Exercise + OA group compared to the Sedentary + OA group. These results suggest that regular walking exercise prior to the development of OA could alleviate joint pain through increases in the expressions of anti-inflammatory cytokines in the rat infrapatellar fat pad and synovium.
我们研究了膝骨关节炎（OA）前常规步行运动对大鼠单碘乙酸（MIA）诱导的膝 OA 模型中疼痛和滑膜炎的影响。71 只雄性 Wistar 大鼠分为三组：（i）静息+OA，（ii）运动+OA，和（iii）静息+假手术组。运动+OA 组进行了为期 6 周的常规跑步机步行运动，速度为 10m/min（每天 60 分钟，每周 5 天），然后在右膝关节注射 2mg MIA。在 6 周运动结束时以及在 MIA 注射后 1 和 6 周时从该组大鼠中取出右膝关节。在 MIA 注射前的 6 周跑步机运动后，三组之间的压力疼痛阈值没有显著差异，而在注射后 1 周，运动+OA 组的压力疼痛阈值明显高于静息+OA 组，这种差异一直持续到实验结束。甲苯胺蓝染色显示关节软骨和软骨下骨的组织学变化在静息+OA 和 EX+OA 组之间没有差异。在髌下脂肪垫和滑膜中，白细胞介素（IL）-4 和 IL-10 mRNA 的表达水平通过跑步机运动显著增加。在 MIA 注射后 1 周，运动+OA 组的 CD68-、CD11c-阳性细胞数量和 IL-1β mRNA 表达减少，CD206-阳性细胞数量增加。与静息+OA 组相比。这些结果表明，OA 发生前的常规步行运动可通过增加大鼠髌下脂肪垫和滑膜中抗炎细胞因子的表达来缓解关节疼痛。
