Effect of electro-acupuncture pretreatment on endoplasmic reticulum stress during global cerebral ischemia-reperfusion in rats

Objective To evaluate the effect of electro-acupuncture pretreatment on endoplasmic reticulum stress during global cerebral ischemia-reperfusion （I/R ） in rats .Methods One hundred and forty-four adult male Sprague-Dawley rats ,weighing 400-500 g ,were randomly divided into 3 groups （ n=48 each） using a random number table：sham operation group （group S ） , I/R group and electro-acupuncture pretreatment group （group EA） .Global cerebral I/R was induced by 4-vessel occlusion method .Bilateral vertebral arteries were permanently occluded by cauterization and bilateral carotid arteries were occluded for 5 min , followed by reperfusion .Electro-acupuncture of Dazhui and Baihui acupoints lasting for 30 min was performed once a day for 5 consecutive days starting from 5 days before ischemia in group EA .At 6 ,12 ,24 and 48 h of reperfusion ,12 rats were sacrificed in each group and hippocampi were removed for microscopic examination and for determination of apoptosis rate （by TUNEL ） and expression of growth arrest-and DNA damage-inducible gene 153 （GADD153 ） protein （by Western blot ） .Results Compared with group S ,the apoptosis rate was significantly increased and the expression of GADD153 protein was up-regulated at 6 ,12 ,24 and 48 h of reperfusion in I/R and EA groups （ P〈0.05） .Compared with group I/R ,the apoptosis rate was significantly decreased and the expression of GADD 153 protein was down-regulated at 6 ,12 ,24 and 48 h of reperfusion in group EA （ P〈 0.05） .The pathological changes were significantly attenuated in group EA as compared with group I/R .Conclusion Electro-acupuncture pretreatment can down-regulate the expression of GADD 153 protein , reduce endoplasmic reticulum stress , and decrease cell apoptosis ,thus attenuating global cerebral I/R injury in rats . Key words: Electric stimulation therapy; Reperfusion injury; Brain; Endoplasmic reticulum