Effect of extracorporeal shock wave on the expression of cytokines and imaging of rabbits with knee osteoarthritis

Abstract

Objective To discuss the influence of extracorporeal shock wave (ESW) on the expression of cytokines and imaging in different therapeutic windows when the ESW therapy was used on rabbit osteoarthritis (OA) model. Methods Forty-eight rabbits were randomly divided into blank group (n=12) and OA group (n=36) by drawing after they were numbered according to their weights. The regular preoperative preparations were used on rabbits in the OA group. After the preparations, the rabbit OA model was established by improved Hulth. After the surgery, the rabbits were divided into three groups by drawing: model group (n=12), therapy group 1 (n=12), and therapy group 2 (n=12). The rabbits in blank group and model group were fed normally and not given ESW. The rabbits in therapy group 1 were subjected to ESW therapy for only once on the day after the surgery. The rabbits in the therapy group 2 received ESW therapy on the day after the surgery, thereafter, once a week. On the 6th, 9th, and 12th week, digital radiography (DR) and the detection of expression of nitric oxide (NO), nitric oxide synthase (NOS) and interleukin (IL)-1 were performed on rabbits chosen randomly from each group. Results The enzyme linked immunosorbent assay (ELISA) showed that the concentrations of NO in the 6th, 12th week [(22.467±2.270) and (25.101±1.409) pg/ml] in the rabbits of therapy group 2 are lower than those of model group [(27.364±0.434), (33.225±1.154) pg/ml, P=0.017, 0.007], NOS in the 12th week [(22.014±1.523) pg/ml] in the rabbits of therapy group 2 are lower than those of model group [(31.939±2.519) pg/ml, P=0.008]. IL-1 in the 9th and 12th week [(183.106±28.548), (213.960±15.256) pg/ml] in the rabbits of therapy group 2 are lower than those of model group obviously [(242.630±27.169), (275.120±21.782) pg/ml, P=0.001, 0.007]. The difference between the two groups is significant. The imaging changes revealed that the severity of knee joint disease in the rabbits of therapy group was reduced. Conclusion ESW can release the oxidative stress injury and inflammatory injury, and slow the progression of the knee osteoarthritis by reducing the expression of NO, NOS and IL-1. Key words: Extracorporeal shock wave; Knee osteoarthritis; Oxidative stress injury; Tissue injury