The Protective Effects Of Repeated Electroacupuncture Preconditioning On Spinal Cord Ischemia Injury Rabbits

BackgroundParaplegia is the most severe complication after thoracoabdominal aneurysm repair. Spinal cord ischemia caused by hypoperfusion during aortic across-clamping is believed to be the cause of acute spinal cord dysfunction. Excitatory amino acid, accumalation of intracellular calcium and oxygen free redicals have been suggested to play important roles in neuronal ischemic injury. However, measures aimed at these factors such as NMDA receptor inhibitors, calcium channel blockers and free radical scavengers showed unsatisfied outcome in their clinical use Therefore, novel preconditioning procedures to protect spinal cord against ischemic injury are remained to be found. Electroacupuncture, a new development of the traditional acupuncture, is widely used in the treatment of spinal cord injury and has been proved to be effective. This study was designed to study the preconditioning effect of electroacupuncture in protecting spinal cord ischemia-reperfusion injury. The finding may provide a new way to clinically practicable preconditioningmeasure. Objective1. To investigate the protective effects of preconditioning with electroacupuncture against spinal cord ischemia-reperfusion injury.2. To investigate the protective effects of preconditioning with electroacupuncture against spinal cord ischemia-reperfusion injury possible mechanism.Methods1. Pretreament with repeated electroacupuncture induced neuroprotection against spinal cord ischemia-reperfusion injury of rabbitsTwenty-four male New Zealand white rabbits were randomly divided to 3 groups(n=8 each), animals in the control group received no treatment; animals in the SP group received sodium pentobarbitone 30 mg/kg i.v. each day for 5 days; animals in EA group were anesthetized with sodium pentobarbitone 30mg/kg i.v. and received electroacupuncture at the Zusanli acupoint 30 min a day for 5 days.Twenty-four hours after the last treatment, spinal cord ischemia was induced by an infrarenal aortic occlusion for 20min. Hind-limb motor function was determined with the Tarlov criteria (in which 4 is normal and 0 is paraplegia) at 4h, 8h, 12h, 24h, and 48h after reperfusion. All animals were sacrificed at 48h after reperfusion and the spinal cords (Ls) were removed immediately for histopathologic study.2. Effects of pretreament with repeated electroacupuncture on biochemistry variables after spinal cord ischemia-reperfusion injury of rabbits.Twenty male New Zealand white rabbits were randomly assigned to 2groups(n=10 each), animals in the control group received no treatment; animals in EA group were anesthetized with sodium pentobarbitone 30mg/kg i.v. and received electroacupuncture at the Zusanli acupoint 30 min a day for 5 days.Twenty-four hours after the last treatment, spinal cord ischemia was induced by an infrarenal aortic occlusion for 20min. The amount of MDA and the activity of SOD in plasma were observed at different time point(before ischemia,after 20min ischemia and after Ih reperfusion). 3. Pretreatment with repeated electroacupuncture increase HSP90 expression after spinal cord ischemia-reperfusion injury of rabbitsSixty male New Zealand white rabbits were randomly assigned to 2 groups(n=8 each), animals in the control group received no treatment; animals in EA group were anesthetized with sodium pentobarbitone 30mg/kg i.v. and received electroacupuncture at the Zusanli acupoint 30 min a day for 5 days.Twenty-four hours after the last treatment, spinal cord ischemia was induced by an infrarenal aortic occlusion for 20min.The HSP90 expression was evaluated at 48h after reperfusion.Results1. Pretreament with repeated electroacupuncture induced neuroprotection against spinal cord ischemia-reperfusion injury of rabbitsThe neurologic outcome and histopathology(48h) in the EA Group were significantly better than the Control group (p<0.01) .There were no difference among Control group and SP group.2. Effects of pretreament with repeated electroacupuncture of biochemistry variables after spinal cord i...