The Study Of Brain Ischemic Torlerance Induced By Electroacupuncture Stimulation

The cerebrovescular disorders with a mortality of 30% has become one of three mostly reasons for death in our modern society and morbidity rate seems to keep rising at present. So, it is focal point that disclosing pathophysiological change wholly during attack and looking for the methods in order to minimize brain ischemic/reperfusion injury that can be forseen as far as possible.Acupuncture treatment for cerebrovescular disorders has been thousants of years in our country. It has been applied widely in clinic because of its effectiveness. Medical workers improved this technic by combination with acupuncture and electric current in recent years and achieved more satisfied results than before. It is called electroacupuncture in medical realm. In our department, we pretreated rats at "Bai hui" a day for Sdays and 30 minites per day by electroacuouncture with 2/15Hz of frequency and 1mA of electric current intensity. We found that this pretreatment obviously attenuated brain ischemic/reperfusion injury caused by left-side occlusion of middle cerebral artery after 24 hours. This study tried to use MACO models of rats for the purpose of disclosing the characteristics and machenism of protective effect induced by electroacupuncture pretreatment.Objective1. To investigate the acupuncture point specificity of brain ischemic tolerance induced by preconditioning with repeated electroacupuncture at "Baihui" acupoint in rats with transient focal cerebral ischemia.2. To investigate the effects of electroacupuncture with various frequencies on the degree of induced brain ischemic tolerance in rats with focal cerebral ischemia.3. To investigate the effect of naloxone on brain ischemic tolerance induced by repeated electroacupuncture stimulation in SD rats.Methods1. The role of 'Baihui' acupoint in the induction of brain ischemic tolerance by preconditioning with electroacupuncture40 SD male rats were randomly divided into 4 groups(n=10 each): Animals in control group received no pretreatment; Animals in PB group were intraperitoneally injected with pentobarbital sodium 40mg/kg a day for 5 days; Animals in EA1 group received electroacupuncture at the "Baihui" acupiont 30 min a day for 5 days under pentobarbital sodium anesthesia; Animals in EA2 group received electroacupuncture at the point 1.0 cm away from "Baihui" 30 min a day for 5 days under the same condition. At 24 hour after the last treatment ,the right middle cerebral artery occlusion model (MCAO) was induced for 120min in all animals. The neurological deficit scores (NDS) were evaluated at 24h after reperfusion and then rats were sacrificed under deep anesthesia. The brain was sliced in 6mm coronal sections and infarct volume was determined by TTC staining.2. Effects of electroacupuncture with various frequencies on the degree of induced brain ischemic tolerance48 male SD rats were randomly divided into 4 groups(n=12 each): group PB, intraperitoneally injected with pentobarbital sodium 40mg/kg once a day for 5 days; The other three groups received electroacupuncture with 2/5Hz,2/15Hz or 2/100Hz respectively at the "Baihui" acupoint 30 min a day for 5 days under pentobarbital sodium anesthesia. At 24 hours after the last pretreatment, all animals were subjected to the right middle cerebral artery occlusion (MCAO) for 120min.The neurological deficit scores (NDS) were evaluated at 24h after reperfusion and then rats were sacrificed under deep anesthesia. The brain was sliced into 6mm coronal sections and infarct volume was determined by TTC staining.3. Effect of naloxone on brain ischemic tolerance induced by repeated electroacupuncture stimulation in SD rats40 male SD rats were randomly divided into 4 groups (n=10 each): Animals in PB group were intraperitoneally injected with pentobarbital sodium 40mg/kg once a day for 5 days; Animals in NX group were intraperitoneally injected with naloxone Img/kg in addition to pentobarbital sodium 40mg/kg once a day for 5 days; Animals received electroacupunctur...