Effect of remote limb ischemic postconditioning combined with electro-acupuncture postconditioning on focal cerebral ischemia-reperfusion injury in rats

Abstract

Objective To evaluate the effect of remote limb ischemic postconditioning(RLIP)combined with electro-acupuncture postconditioning(EAP)on focal cerebral ischemia-reperfusion(I/R)injury in rats. Methods Seventy male Sprague-Dawley rats, weighing 220-250 g, were randomly assigned into 5 groups(n=14 each)using a random number table: sham operation group(group S), group I/R, RLIP group, EAP group and RLIP combined with EAP group(group RLIP+ EAP). Focal cerebral I/R was induced by middle cerebral artery occlusion(MCAO). MCAO was maintained for 120 min.The animals were subjected to 3 cycles of 15 min ischemia of bilateral hind limbs followed by 30 s reperfusion starting from onset of reperfusion.Dazhui and Baihui acupoints were stimulated with electric stimulator(frequency 15 Hz/2 Hz, intensity 1 mA)for 30 min starting from onset of reperfusion.Neurological deficit scores(NDSs)were evaluated at 24 h of reperfusion.The animals were then sacrificed and brains were removed to measure the infarct size and for microscopic examination of pathological changes in hippocampal CA1 region.The number of survival neurons was counted.The apoptosis in neurons was determined by TUNEL.Apoptosis index was calculated. Results Compared with group S, the NDSs, percentage of cerebral infarct size and AI were significantly increased, and the number of survival neurons was decreased in the other four groups.Compared with group I/R, the NDSs, percentage of cerebral infarct size and AI were significantly decreased, and the number of survival neurons was increased in EAP, RLIP and RLIP+ EAP groups.Compared with RLIP and EAP groups, the NDSs, percentage of cerebral infarct size and AI were significantly decreased, and the number of survival neurons was increased in group RLIP+ EAP. Conclusion The combination of RLIP and EAP provides better efficacy than either alone in attenuating focal cerebral I/R injury in rats. Key words: Electric stimulation therapy; Brain; Reperfusion injury; Extremities; Ischemic postconditioning