[Influence of electroacupuncture on the expression of cyclooxygenase mRNA and protein in rats with air-pouch plus recombinant human IL-1beta induced inflammation at the back].

OBJECTIVE

To observe the effect of electroacupuncture (EA) on changes of cyclooxygenase (COX)-2 mRNA and protein expression after inflammation occurrence at the back by application of human recombinant IL-1beta (hr IL-Ibeta) plus air-pouch in rats, so as to analyze the relativity between EA-induced changes of COX-2 expression and proinflammatory cytokines regulative pathway.

METHODS

Ninety female Wistar rats were randomized into control, model, and EA groups with 30 cases in each. Inflammatory model was established by subcutaneous implantation of a sterilized hollow teflon cylinder (sac, 1.5 mi in volume) at the back and intrasaccal injection of hr IL-1beta (10 ng/ml). EA (2 Hz, 1 mA) was immediately applied to "Quchi" (LI 11) for 30 min. Exudate in the sac was withdrawn at various intervals after hr IL-1beta-injection for assaying COX-2 mRNA expression with RT-PCR and protein expression with Western Blotting.

RESULTS

In comparison with control group, one hour (h) after hr IL-1beta-injection, COX-2 mRNA and protein expression levels were up-regulated significantly in model group (P < 0.01); while compared to model group, COX-2 mRNA and protein expression levels in EA group were down-regulated considerably (P < 0.05). 5 h and 24 h after hr IL-1beta-injection, COX-2 mRNA expression in model and EA groups was significantly higher than that in control group (P < 0.01), and no significant differences were found between model and EA groups in COX-2 mRNA expression levels (P > 0.05). On the contrary, 5 h after administration of hr IL-1beta, COX-2 protein expression in model group was significantly higher than that in control group (P < 0.05). On the 24 h after hr Ibeta-1beta-injection, no significant differences were found in COX-2 protein expression levels among control, model and EA groups (P > 0.05).

CONCLUSION

EA can effectively suppress hr IL-1beta-injection induced up-regulation of COX-2 mRNA and protein expression in the rats, suggesting a close relativity between the regulation of proinflammatory cytokines and EA-induced inhibition of COX-2 mRNA and protein expression.