Immunohistochemical staining in each group.

<p>Increase in the frequency with same amount of treadmill exercise decreased the MIA-induced degradation of COL2A1 in articular cartilage and reduced the expression of MMP-13 and NF-κB p65. The micrographs showed the intensity of immunohistochemical staining of COL2A1, NF-κB p65, MMP-13, and TIMP-1 in the articular cartilage of each experimental group, and the figures showed the percentages of positively stained cells. Differences between CG and OAG were significant (*<i>P</i> <0.001, *^a<i>P</i> = 0.001), and differences between OAG and the treadmill exercise groups were significant (⁺<i>P</i><0.001, ^+a<i>P</i> = 0.012). One-way ANOVA, n = 5 rats for each group, mean score with 95% confidence interval.