[Effect of electroacupuncture at "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) on collagen-induced arthritis and secretory function of knee-joint synoviocytes in rats].

Objective: To observe the effect of electroacupuncture (EA) of "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) on collagen-induced arthritis (CIA) and its underlying mechanism in regulating the secretory function of knee-joint synovial cells in CIA rats.

Methods: Thirty-six Wistar rats were equally randomized into control, model and EA groups. CIA model (rheumatoid arthritis) was duplicated by intradermal injection of Bovine type II collagen into the back of the anesthetized rats. EA (2 Hz, 2 mA) was applied to "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) for 30 min, once a day for 30 days. The paw volume was measured by using a Plethysmometer and hot water tail-flick tests (50 degrees C) were conducted for detecting the rats' pain threshold (PT) before and after the treatment. The contents of PGE2, IL-1beta and TNF-alpha in supernatant of the cultured joint synoviocytes were detected by enzyme linked immunosorbent assay (ELISA).

Results: In comparison with control group, the swelled paw volume, the declined PT, PGE2, TNF-alpha and IL-1beta contents in knee-joint synoviocyte supernatant were significantly higher in model group (P < 0.05). Compared with model group, PT increased obviously (P < 0.05); paw volume, supernatant PGE2, TNF-alpha and IL-1beta contents decreased obviously (P < 0.05) in EA group.

Conclusion: EA of ST 36 and SP 6 has a pronounced therapeutic effect in relieving knee joint pain and inflammation in CIA rats, which may be related to its effect in regulating the secretory function of the knee-joint synoviocytes.