[Effects of electroacupuncture on synovia free radicals in rabbits with knee osteoarthritis]

To observe the effect of electroacupuncture( EA) on synovia superoxide dismutase (SOD) activity, malondialdehyde (MDA) and nitric oxide (NO) contents in rabbits with knee osteoarthritis (KOA).

A total of 40 New Zealand rabbits were randomly divided into control, model, massage and EA groups, with 10 cases in each. KOA model was established by gypusum fixing method. EA (1.6-2 Hz, 1-2 mA) was applied to left "Yanglingquan" (GB 34), "Xuehai" (SP 10), "Zusanli" (ST 36) and "Liangqiu" (ST 34) for 25 min, once daily for 21 days. For massage group, the affected knee joint was pressed, kneaded, stretched and rotated repeatedly for 15 min every time, followed by forced running about 100 m. The intra-joint synovia was collected (0.4-0.6 ml) for detecting contents of SOD with xanthine oxidase method, MDA with thiobarbituric acid method and NO with nitrate reductase method.

Compared with control group, synovia SOD activity in model group decreased considerably (P<0.05), while MDA and NO contents increased significantly (P<0.05). After 3 weeks' treatment, compared with pre-treatment and model group, synovia SOD activity increased markedly (P<0.05), and MDA and NO contents lowered remarkably in both EA and massage groups (P<0.05). No significant differences were found between EA and massage groups in these 3 indexes (P>0.05).

Both EA and massage can raise synovia SOD activity and lower MDA and NO content, which may contribute to their effect in relieving knee osteoarthritis in the rabbit.