Effect of 99Tc-MDP on the receptor activator of nuclear factor-κB ligand/osteoprotegerin system of type Ⅱ collagen-induced arthritis in rats / 中华风湿病学杂志

ABSTRACT

Objective To study the effect of 99Tc-MDP on receptor activator of nuclear factor-κB ligand/osteoprotegerin (RANKL/OPG) system of collagen-induced arthritis (CIA) rat. Methods The CIA was established by subcutaneous injection with type Ⅱ collagen and complete Freud's adjuvant to rats, except the group (n=8, treated with 99Tc-MDP). The histopathological changes of joints were scored based on the extent of infiltration of inflammatory cells, cartilage destruction and bone erosion. The serum levels of RANKL/OPG were tested with ELISA, and the synovial membrane levels of RANKL/OPG were tested with Western blot.Repeated ANOVA and one way ANOVA were used for statistical analysis. Results The MTX group relative value of RANKL/OPG in serum [35 d (1.076±0.016), 42 d (1.140±0.005), 49 d (1.155±0.023)], and in synovial membrane (1.156±0.014), and the histopathological scores [synovial membrane (1.8±0.5), cartilage (1.9±0.6), bone (1.8±0.5) ] were lower than model group ( 1.269±0.025, 1.296±0.015, 1.340±0.011 ), (2.9±0.4, 2.6±0.5, 2.6±0.5), ( 1.340±0.013 )(P＜0.01 ). And all above index of 99Tc-MDP group ( 1.035±0.034,0.986±0.019, 0.991±0.020), (1.5±0.5, 1.4±0.5, 1.2±0.5), (0.098±0.026) were notably lower than the MTX treat ment group (P＜0.01). Conclusion 99Tc-MDP may retard the progression of the disease by decreasing the relative RANKL/OPG expression and it can initiate its effect earlier than MTX.