首页|期刊导航|中华医学杂志（英文版）|Involvement of δ-and μ-opioid receptors in the delayed cerebral ischemic tolerance induced by repeated electroacupuncture preconditioning in rats
中华医学杂志（英文版）2007，Vol.120Issue(5)：394-399,6.
Involvement of δ-and μ-opioid receptors in the delayed cerebral ischemic tolerance induced by repeated electroacupuncture preconditioning in rats
Involvement of δ-and μ-opioid receptors in the delayed cerebral ischemic tolerance induced by repeated electroacupuncture preconditioning in rats
摘要
Abstract
Background Preconditioning with repeated electroacupuncture (EA) could mimic ischemic preconditioning to induce cerebral ischemic tolerance in rats. The present study was designed to investigate whether mu(μ)-, delta(δ)- or kappa(κ)-opioid receptors are involved in the neuroprotection induced by repeated EA preconditioning.Methods The rats were pretreated with naltrindole (NTI), nor-binaltorphimine (nor-BNI) or D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), which is a highly selective δ-, κ- or μ-opioid receptor antagonist respectively, before each EA preconditioning (30 minutes per day, 5 days). Twenty-four hours after the last EA treatment, the middle cerebral artery occlusion (MCAO) was induced for 120 minutes. The brain infarct volume was determined with 2,3,5-triphenyltetrazolium chloride staining at 24 hours after MCAO and compared with that in rats which only received EA preconditioning. In another experiment, the met-enkephalin-like immunoreactivity in rat brain was investigated by immunohistochemistry in both EA preconditioning and control rats.Results The EA preconditioning reduced brain infarct volume compared with the control rats (P=0.000). Administration of both NTI and CTOP attenuated the brain infarct volume reduction induced by EA preconditioning, presenting with larger infarct volume than that in the EA preconditioning rats (P＜0.001). But nor-BNI administration did not block the infarct volume reduction induced by EA preconditioning, presenting with smaller infarct volume than the control group rats(P=0.000). The number of met-enkephalin-like immunoreactivity positive neurons in the EA preconditioning rats was more than that of the control rats (P=0.000).Conclusion Repeated EA preconditioning stimulates the release of enkephalins, which may bind δ- and μ-opioid receptors to induce the tolerance against focal cerebral ischemia.关键词
electroacupuncture/ preconditioning/ ischemic tolerance/ opioid receptor/ enkephalinKey words
electroacupuncture/ preconditioning/ ischemic tolerance/ opioid receptor/ enkephalin分类
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XIONG Li-ze,YANG Jing,WANG Qiang,LU Zhi-hong..Involvement of δ-and μ-opioid receptors in the delayed cerebral ischemic tolerance induced by repeated electroacupuncture preconditioning in rats[J].中华医学杂志（英文版）,2007,120(5):394-399,6.基金项目
This work was supported by a grant from the National Natural Science Foundation of China (No. 30471664). （No. 30471664）
