Interleukin1β (IL 1β) is a proinflammatory cytokine and plays an important role in the pathogenesis of cerebral ischemia. The expression of IL 1β and its receptor antagonist (IL 1Ra) after cerebral ischemia is not well defined so far. The aim of present study was to explore the effect of electroacupuncture (EA) on the expression of IL 1β and IL 1Ra in rats after middle cerebral artery occlusion (MCAo) and reperfusion. Using in situ hybridization and RT PCR techniques, it was found that in the MCAo group the expression of IL 1β mRNA was markedly increased at 2 hr, 6 hr and 12 hr after reperfusion in the ischemic cerebral cortex compared with normal group. The IL 1Ra mRNA expression was rapidly induced by MCAo, and also increased significantly at 12 hr, reaching a peak level at 24 hr of reperfusion in ischemic cortex. In ischemic striatum the IL 1Ra mRNA was increased only at 12 hr after ischemia/reperfusion and decreased significantly at 24 hr after ischemia/reperfusion. In EA + MCAo group the expression of IL 1β mRNA in ischemic cortex was significantly decreased at 2 hr, 6 hr and 12 hr; but the expression of IL 1Ra mRNA was increased significantly compared with MCAo group 24 hr after reperfusion in the cerebral cortex and stratium. Our results indicated that EA stimulation of "Shuigou" (GV 26) and "Baihui" (GV 20) acupoints could downregulate the IL 1β mRNA expression and upregulate the IL 1Ra mRNA expression in cerebral ischemic rats, which might be the neuroprotective effect of EA on cerebral ischemia, and one of the mechanisms of EA anti-ischemia.
