Electroacupuncture, Calpain I Expression, and Survival of Hippocampal Neurons in Cerebral Ischemia Reperfusion Rats

Abstract

Background: Acupuncture is being recognized as an effective treatment for stroke. However, the mechanisms of this therapy remain unclear. We hypothesized that part of acupuncture's efficacy is regulation of the expression of calpain I. Objectives: To investigate the effects of electroacupuncture on calpain I expression in a focal cerebral ischemia reperfusion rat model and to investigate its molecular mechanisms. Design and Setting: Fifty male Sprague-Dawley rats were studied in this experiment. Intervention: Left middle cerebral artery occlusion models (MCAO) were established. Electroacupuncture treatment was performed in these cerebral ischemia reperfusion rats at Shuigou (GV 26) and Neiguan (PC 6 bilateral) acupoints. For the placebo group, points were needled at bilateral armpit 3 mm. Points in both groups were stimulated at 3 mA and 2 Hz for 10 minutes, every 12 hours until reperfusion for 48 hours. Main Outcome Measure: Calpain I, spectrin αII, and calpastatin expression in hippocampus CA1 region in response to electroacupuncture. Results: We found that cerebral ischemia reperfusion induced calpain I mRNA and protein expression in hippocampus CA1 region, and electroacupuncture significantly attenuated the increasing calpain I expression (P < .05). We also found that electroacupuncture increased spectrin αII, calpastatin protein levels, and the survival rate of neurons in the hippocampus CA1 region in cerebral ischemia reperfusion rats (all P < .05). Conclusions: Our findings suggest that electroacupuncture may provide protection against cerebral ischemia reperfusion injury in rats. This study also provided insight into potential mechanisms of electroacupuncture therapy for stroke.