OBJCETIVE Epidemiologic studies have demonstrated that consumption of moderate amounts of red wine is associated with significant reductions in incidences of cardiovascular and cerebrovascular diseases,which may be re...OBJCETIVE Epidemiologic studies have demonstrated that consumption of moderate amounts of red wine is associated with significant reductions in incidences of cardiovascular and cerebrovascular diseases,which may be related to alcohol in red wine.Our previous study demonstrated that ethanol ingestion 24 h prior to induction of cerebral ischemic/reperfusion(I/R)reduced delayed neuronal death(DND).Our most recent results supported a role for big Ca2+-sensitive K+channel(BKCa channel)activation in the neuroprotective effects of ethanol preconditioning(Et OH-PC)in global cerebral I/R.Therefore,we hypothesis that moderate Et OH-PC activates BKCa channel to protect brain damage induced by focal cerebral I/R.This project will utilize focal cerebral I/R animal model to explore the function of BKCa channel in Et OH-PC protection in vivo levels by means of pharmacological intervention such as BKCa channel opene(rNS11021,NS)and blocke(rpaxilline,PX).The results will provide theoretical evidence for neuroprotective effect of moderate alcohol preconditioning against ischemic stroke,and the conclusion will also bring to a concept that extrinsic moderate ethanol preconditioning may activate intrinsic protective mechanism in the brain.METHODS The SD rat were randomly divided into the following six groups(n=10):sham,I/R,Et OH-PC+I/R,NS11021-PC+I/R,paxilline+Et OH-PC+I/R,Paxilline+NS11021-PC+I/R.Both Et OH-PC and NS11021-PC(0.1mg·kg-1;ip)were induced 24 h before I/R.The volume of 95%ethanol to be instilled(inμL)was calculated as follows:〔body weight(g)×0.6〕+0.3.This volume of ethanol was mixed in 0.3 m L of sterile distilled water just before administration to the animals by gavage.The Paxilline(2.5 mg·kg-1;ip)was administered 10min beforeEt OH-PC and NS11021-PC.The right middle cerebral artery occlusion(MCAO)was produced by inversion of a 4-0-nylon filament.The filament was withdrawn 2 h after onset of MCAO and then reperfused.Neurological deficits and infarct volume were measured 24 h after I/R.Another 36 rats were randomly divided into 6 groups as above,6 in each group.DWI were performed 2h after ischemic and T2WI MRI were performed 24 h after I/R to observe the infarct volume of brain and the penumbra volume of brain in each group.Then rats were killed and detected the apoptotic cell death and degeneration of neurons.RESULTS Compared to I/R group,the neurological score(P<0.01),the infarct volume of brain(P<0.01),the infarct volume of ischemic penumbra(P<0.01),the percentage of apoptotic cell death(P<0.01)and the percentage of degenerative neurons(P<0.01)were significantly decreased after ethanol preconditioning,while these changes were reversed by paxilline(P<0.05);compared to I/R group,the neurological score(P<0.01),the infarct volume of brain(P<0.01),the infarct volume of ischemic penumbra(P<0.01),the percentage of apoptotic cell death(P<0.01)and the percentage of degenerative neurons(P<0.01)were significantly decreased after NS11021 preconditioning,while these changes were reversed by paxilline(P<0.05).CONCLUSION Our results show that moderate alcohol preconditioning activates BKCa channels to protect brain damage induced by focal cerebral I/R.展开更多
目的:观察有氧运动对大鼠脑动脉平滑肌细胞(SMC)的大电导钙激活钾通道(BKCa)生物物理特性的影响,为运动有效预防脑血管疾病的细胞学机制提供实验依据。方法:8周龄雄性Wistar大鼠20只,随机分为两组,安静对照组(SED)和运动组(EX)。运动组...目的:观察有氧运动对大鼠脑动脉平滑肌细胞(SMC)的大电导钙激活钾通道(BKCa)生物物理特性的影响,为运动有效预防脑血管疾病的细胞学机制提供实验依据。方法:8周龄雄性Wistar大鼠20只,随机分为两组,安静对照组(SED)和运动组(EX)。运动组进行12周跑台运动(20 m/min,60 min/d,5 d/w)。12周后,取脑动脉,经酶消化法获得单个脑动脉SMC。采用膜片钳单通道内面向外记录模式,观察各组BKCa通道的生物物理特性。结果:1)本实验中BKCa的单通道电导为221.8±6.1p S(n=8),记录电流反转电位接近0 m V,无整流现象,均符合BKCa单通道特征;2)12周有氧运动使BKCa通道活性提高:钳制电位+40 m V,[Ca2+]i为1μM时,SED和EX组BKCa通道平均开放概率分别为0.28±0.02和0.78±0.07 p S 3)有氧运动使BKCa通道电压依赖性增强:[Ca2+]i为1μM时,SED和EX组开放概率-电压曲线左移,V1/2分别为48.09±3.27 m V和26.57±3.17 m V;4)有氧运动使BKCa通道钙敏感性增强:膜电位+40 m V下,SED和EX组Po-[Ca2+]i曲线左移,Kd值分别为2.80±0.09μM和0.35±0.09μM;5)运动组大鼠BKCa通道平均开放时间(To)增大,平均关闭时间(Tc)缩短,开放时间常数(τO)增大,关闭时间常数(τC)减小,提示有氧运动使通道更易开放且更难关闭。结论:长期规律性有氧运动能改变大鼠SMC的BKCa通道门控特性,使其活性增强,这可能是运动改善脑血管舒缩功能,增强脑动脉供血的重要机制之一。展开更多
基金The project supported by NSFC(81171079,81271312)
文摘OBJCETIVE Epidemiologic studies have demonstrated that consumption of moderate amounts of red wine is associated with significant reductions in incidences of cardiovascular and cerebrovascular diseases,which may be related to alcohol in red wine.Our previous study demonstrated that ethanol ingestion 24 h prior to induction of cerebral ischemic/reperfusion(I/R)reduced delayed neuronal death(DND).Our most recent results supported a role for big Ca2+-sensitive K+channel(BKCa channel)activation in the neuroprotective effects of ethanol preconditioning(Et OH-PC)in global cerebral I/R.Therefore,we hypothesis that moderate Et OH-PC activates BKCa channel to protect brain damage induced by focal cerebral I/R.This project will utilize focal cerebral I/R animal model to explore the function of BKCa channel in Et OH-PC protection in vivo levels by means of pharmacological intervention such as BKCa channel opene(rNS11021,NS)and blocke(rpaxilline,PX).The results will provide theoretical evidence for neuroprotective effect of moderate alcohol preconditioning against ischemic stroke,and the conclusion will also bring to a concept that extrinsic moderate ethanol preconditioning may activate intrinsic protective mechanism in the brain.METHODS The SD rat were randomly divided into the following six groups(n=10):sham,I/R,Et OH-PC+I/R,NS11021-PC+I/R,paxilline+Et OH-PC+I/R,Paxilline+NS11021-PC+I/R.Both Et OH-PC and NS11021-PC(0.1mg·kg-1;ip)were induced 24 h before I/R.The volume of 95%ethanol to be instilled(inμL)was calculated as follows:〔body weight(g)×0.6〕+0.3.This volume of ethanol was mixed in 0.3 m L of sterile distilled water just before administration to the animals by gavage.The Paxilline(2.5 mg·kg-1;ip)was administered 10min beforeEt OH-PC and NS11021-PC.The right middle cerebral artery occlusion(MCAO)was produced by inversion of a 4-0-nylon filament.The filament was withdrawn 2 h after onset of MCAO and then reperfused.Neurological deficits and infarct volume were measured 24 h after I/R.Another 36 rats were randomly divided into 6 groups as above,6 in each group.DWI were performed 2h after ischemic and T2WI MRI were performed 24 h after I/R to observe the infarct volume of brain and the penumbra volume of brain in each group.Then rats were killed and detected the apoptotic cell death and degeneration of neurons.RESULTS Compared to I/R group,the neurological score(P<0.01),the infarct volume of brain(P<0.01),the infarct volume of ischemic penumbra(P<0.01),the percentage of apoptotic cell death(P<0.01)and the percentage of degenerative neurons(P<0.01)were significantly decreased after ethanol preconditioning,while these changes were reversed by paxilline(P<0.05);compared to I/R group,the neurological score(P<0.01),the infarct volume of brain(P<0.01),the infarct volume of ischemic penumbra(P<0.01),the percentage of apoptotic cell death(P<0.01)and the percentage of degenerative neurons(P<0.01)were significantly decreased after NS11021 preconditioning,while these changes were reversed by paxilline(P<0.05).CONCLUSION Our results show that moderate alcohol preconditioning activates BKCa channels to protect brain damage induced by focal cerebral I/R.
文摘目的:观察有氧运动对大鼠脑动脉平滑肌细胞(SMC)的大电导钙激活钾通道(BKCa)生物物理特性的影响,为运动有效预防脑血管疾病的细胞学机制提供实验依据。方法:8周龄雄性Wistar大鼠20只,随机分为两组,安静对照组(SED)和运动组(EX)。运动组进行12周跑台运动(20 m/min,60 min/d,5 d/w)。12周后,取脑动脉,经酶消化法获得单个脑动脉SMC。采用膜片钳单通道内面向外记录模式,观察各组BKCa通道的生物物理特性。结果:1)本实验中BKCa的单通道电导为221.8±6.1p S(n=8),记录电流反转电位接近0 m V,无整流现象,均符合BKCa单通道特征;2)12周有氧运动使BKCa通道活性提高:钳制电位+40 m V,[Ca2+]i为1μM时,SED和EX组BKCa通道平均开放概率分别为0.28±0.02和0.78±0.07 p S 3)有氧运动使BKCa通道电压依赖性增强:[Ca2+]i为1μM时,SED和EX组开放概率-电压曲线左移,V1/2分别为48.09±3.27 m V和26.57±3.17 m V;4)有氧运动使BKCa通道钙敏感性增强:膜电位+40 m V下,SED和EX组Po-[Ca2+]i曲线左移,Kd值分别为2.80±0.09μM和0.35±0.09μM;5)运动组大鼠BKCa通道平均开放时间(To)增大,平均关闭时间(Tc)缩短,开放时间常数(τO)增大,关闭时间常数(τC)减小,提示有氧运动使通道更易开放且更难关闭。结论:长期规律性有氧运动能改变大鼠SMC的BKCa通道门控特性,使其活性增强,这可能是运动改善脑血管舒缩功能,增强脑动脉供血的重要机制之一。
