不同剂量右美托咪定对大鼠海马神经元缺氧复氧损伤中线粒体分裂的影响

目的探讨不同剂量的右美托咪定(dexmedetomidine,Dex)在大鼠海马神经元缺氧复氧损伤中对线粒体分裂的影响。方法 24h内出生的雄性SD大鼠,断头分离海马区神经组织,收集获得神经元细胞进行培养,8d后培养的海马神经元随机分为六组:正常对照组(C组);赋形剂组(V组);缺氧复氧组(HR)组;缺氧复氧+右美托咪定组(D1、D2、D3)组。C组:正常培养;V组:不行缺氧复氧、加入赋形剂二甲基亚砜培养6h,浓度0.01%;HR组:氧糖剥夺法缺氧6h,复氧12h建立缺氧复氧损伤模型;D1、D2、D3组,于缺氧6h后分别加入右美托咪定0.1、1、10μmol/L。采用激光共聚焦显微镜观察各组神经元细胞质Ca2+荧光强度,采用ELISA法检测细胞钙调神经磷酸酶活性,采用透射电镜观察线粒体的超微结构,Western-blot法检测线粒体分裂蛋白Drp1、Fis1的含量。结果与C组比较,HR组、D1组、D2组和D3组线粒体超微结构破坏加重,Ca2+荧光强度、CaN活性明显增强,Fis1、Drp1蛋白含量明显升高(P0.05);与HR组比较,D1组、D2组和D3组线粒体超微结构破坏减轻,Ca2+荧光强度、CaN活性明显减弱,Fis1、Drp1蛋白含量明显降低(P0.05);与D1组和D3组比较,D2组线粒体结构更加完整,Ca2+荧光强度、CaN活性明显减弱,Fis1、Drp1蛋白含量明显降低(P0.05)。C组和V组各指标差异无统计学意义。结论右美托咪定0.1、1、10μmol/L可以减少大鼠海马神经元缺氧复氧损伤中线粒体的分裂,其中1μmol/L是最佳的保护浓度,其机制可能是与其抑制钙超载有关。     

丙泊酚诱导血红素氧化酶-1表达抑制氧糖剥夺大鼠海马神经元凋亡及机制研究

目的 研究丙泊酚诱导血红素氧化酶-1(HO-1)蛋白表达抑制氧糖剥夺海马神经元凋亡的机制.方法 将培养7d的新生(出生24～48 h)SD大鼠海马神经元随机均分为五组:C1组,海马神经元全量换液后再继续培养24 h;C2组,海马神经元接受50μmol/L丙泊酚处理1h后,再继续培养24 h;D组,海马神经元进行缺糖缺氧培养1h后复糖复氧,再继续培养24 h;P组,海马神经元缺糖缺氧的同时接受50 μmol/L丙泊酚处理;Z组,在海马神经元进行缺糖缺氧的同时加入锌原卟啉(ZnpplX)使其终浓度为10 μmol/L后处理同P组.每组分别取12孔海马神经元,用Hoechst33342染色法检测细胞凋亡,用免疫细胞化学染色法检测HO-1蛋白和Bcl-2蛋白的表达.结果 与C1组比较,C2、D及P组海马神经元HO-1和Bcl-2蛋白的表达均增加,D、P及Z组凋亡率显著升高(P＜0.05或P＜0.01).与D组比较,P组海马神经元HO-1和Bcl-2蛋白表达均增加,凋亡率下降(P＜0.01).与P组比较,Z组海马神经元HO-1和Bol-2蛋白的表达均降低,凋亡率则明显升高(P＜0.01).结论 丙泊酚通过诱导氧糖剥夺海马神经元表达HO-1,进而上调Bcl-2,从而抑制氧糖剥夺海马神经元的凋亡,可能是丙泊酚神经保护作用的机制之一.     

YAP/OPA1信号通路在丙泊酚减轻小鼠海马神经元氧糖剥夺-复氧复糖损伤中的作用

目的评价Yes相关蛋白(YAP)/视神经萎缩蛋白1(OPA1)信号通路在丙泊酚减轻小鼠海马神经元氧糖剥夺-复氧复糖损伤中的作用。方法取正常培养处于对数生长期的HT22小鼠海马神经元, 采用随机数字表法分为4组(n=54):对照组(C组)、氧糖剥夺-复氧复糖组(OGD/R组)、丙泊酚组(P组)和丙泊酚+YAP沉默组(P+ siRNA-YAP组)。采用无糖无氧孵育6 h、复氧复糖培养24 h的方法制备神经元氧糖剥夺-复氧复糖损伤模型。P组于复氧复糖即刻加入丙泊酚终浓度50 μmol/L。P+ siRNA-YAP组于模型制备前48 h转染siRNA-YAP。采用CCK-8法检测神经元活力, 采用流式细胞术检测ROS含量和凋亡率, 采用分光光度法检测MDA含量、SOD活性以及线粒体膜电位(MMP), 采用荧光素荧光酶发光法检测线粒体ATP含量, 采用免疫荧光法观察YAP核转位, Western blot法检测YAP、磷酸化YAP(p-YAP)以及OPA1的表达。结果与C组比较, OGD/R组神经元活力降低, ROS、MDA含量和凋亡率升高, SOD活性、MMP和线粒体ATP含量降低, p-YA...     

异丙酚对大鼠海马神经元缺氧复氧时线粒体膜通透性的影响

目的 探讨异丙酚对大鼠海马神经元缺氧复氧时线粒体膜通透性的影响.方法 原代培养胎鼠海马神经元,随机分为3组:对照组(C组)正常培养;模型组(M组)缺氧低糖培养2 h后复氧;异丙酚组(P组)缺氧低糖培养前加入异丙酚,终浓度20 μmol/L.各组于复氧后即刻、4、8、12和24 h(T1～5)时分别用噻唑蓝比色法测定神经元活力,流式细胞仪检测线粒体膜电位(MMP),于T5时采用激光共聚焦显微镜观察细胞膜与线粒体膜通透性.结果 与C组相比,M组T1-5时神经元活力和MMP降低(P＜0.05),T5时细胞膜与线粒体膜通透性增加;与M组相比,P组T1～4时神经元活力升高,T1～5时MMP增加(P＜0.05),T5时细胞膜与线粒体膜通透性降低,完整性改善.结论 异丙酚可通过提高MMP,改善细胞膜与线粒体膜通透性,增强神经元活力,从而减轻大鼠海马神经元缺氧复氧损伤.     

二氮嗪预先给药对原代培养大鼠海马神经元缺氧/复氧损伤的保护机制

目的研究ATP敏感性钾通道开放剂二氮嗪预先给药对新生Wistar大鼠原代培养海马神经元缺氧/复氧损伤的保护机制。方法原代培养的新生大鼠海马神经元随机分为2组,二氮嗪组(Dia组),缺氧前给予50μmol/L二氮嗪;对照组(Con组),给予二氮嗪的赋形剂,即含2‰二甲基亚砜的0.01 mol/L磷酸盐缓冲液;分别在缺氧3 h/复氧24 h和缺氧3 h/复氧48 h后,测定神经元存活能力及LDH漏出率;在缺氧3 h/复氧24 h后,测定丙二醛(MDA)和超氧化物歧化酶(SOD)水平;在缺氧3 h、缺氧3 h/复氧24 h和缺氧3 h/复氧48 h时,测定早期神经元凋亡率和死亡率。结果与Con组比较,Dia 组缺氧3 h复氧24 h时神经元存活能力升高,缺氧3 h/复氧48 h时LDH漏出率降低,缺氧3 h/复氧24 h培养液中MDA浓度降低,SOD活性升高(P<0.05或0.01);缺氧复氧各时点Dia组神经元坏死率降低,神经元凋亡率升高(P<0.05或0.01)。结论50 μmol/L二氮嗪预先给药减轻原代培养新生Wistar 大鼠海马神经元缺氧/复氧损伤的机制与增加SOD活性有关。     

丙泊酚对大鼠前脑缺血/再灌注诱导线粒体损伤及解耦联蛋白2表达的影响

目的 探讨丙泊酚对大鼠前脑缺血/再灌注(ischemia reprfnsion,I/R)诱导线粒体损伤及解耦联蛋白2(uncoupling protein 2,UCP 2)表达的影响.方法 45只健康雄性Wistar大鼠,体重250 g～300 g,按随机数字表法分为3组(n=15).采用"二血管阻断法"制备大鼠前脑I/R损伤模型.假手术组(C组):暴露双侧颈总动脉后,侧脑室注射生理盐水1 mg/kg;缺血/再灌注(I/R组):脑缺血后侧脑室注射生理盐水1 mg/kg;丙泊酚干预组(P组):脑缺血后侧脑室注射丙泊酚1 mg/kg.各组分别于再灌注后24 h断头取海马组织,提取海马组织线粒体,加入CaCl2于37℃下孵育5 min.透射电镜下观察线粒体形态学改变(n=3);紫外分光光度计法检测线粒体通透性转换孔(mitochondrial permeability transition pore,MPTP)活性(n=6);Western blotting法检测解耦联蛋白2的表达(n=6).结果 电镜下C组线粒体结构完整,I/R组可见线粒体显著肿胀、嵴断裂、膜破裂,P组损伤程度轻于I/R组.C组、I/R组和P组线粒体吸光度值均下降;与C组相比,I/R组和P组线粒体吸光度值明显下降(p<0.05);与I/R组(0.028±0.007)相比,P组(0.017±0.007)吸光度值下降幅度减小(P<0.05).与C组(0.62±0.05)相比,I/R组(0.88±0.14)和P组(1.32± 0.10)UCP2蛋白表达上调(P<0.05);P组UCP2蛋白表达高于I/R组(P<0.05).结论 丙泊酚能够改善大鼠前脑t/R后线粒体形态,促进神经细胞线粒体UCP2表达上调,抑制线粒体经ca2+诱导后MPTP开放,从而改善线粒体功能,这可能是丙泊酚减轻脑I/R损伤的机制之一.     

血红素加氧酶-1对氧糖剥夺海马神经元CDK5-ATM-P53信号转导通路的影响

目的 评价血红素加氧酶-1(HO-1)对氧糖剥夺神经元细胞周期蛋白依赖激酶5(CDK5)-共济失调-毛细血管扩张突变基因(ATM)-P53信号转导通路的影响.方法 培养7d的海马神经元,采用随机数字表法,将其随机分为4组(n=10):正常培养组(C组)、氧糖剥夺组(D组)、氧糖剥夺+血晶素(HO-1诱导剂)组(D+H组)和氧糖剥夺+血晶素+锌原卟啉(HO-1抑制剂)组(D+H+T组).C组采用正常培养方法培养.D组神经元进行缺糖、缺氧后复糖、复氧处理.D+H组神经元用10μmol/L血晶素处理24h后进行缺糖、缺氧后复糖、复氧处理.D+H+T组神经元同时用10μmol/L血晶素和10 μmol/L锌原卟啉处理24h后进行缺糖、缺氧后复糖、复氧处理.培养24h后,MTT法检测神经元存活情况,TUNEL法检测神经元凋亡情况,RT- PCR法检测HO-1 mRNA表达,Western blot 法检测HO-1、CDK5、ATM和P53蛋白表达.结果 与C组比较,D组神经元HO-1 mRNA、HO-1、CDK5、ATM和P53蛋白表达上调,神经元存活率降低,神经元凋亡率升高(P＜0.01);与D组比较,D+H组神经元HO-1 mRNA和HO-1蛋白表达上调,CDK5、ATM和P53蛋白表达下调,神经元存活率升高,神经元凋亡率降低(P＜0.01);与D+H组比较,D+H+T组神经元HO-1 mRNA和HO-1蛋白表达下调,CDK5、ATM和P53蛋白表达上调,神经元存活率降低,神经元凋亡率升高(P＜0.01).结论 HO-1可通过阻断氧糖剥夺海马神经元CDK5- ATM-P53信号转导通路抑制神经元凋亡.     

二氮嗪预处理对缺氧复氧后大鼠海马神经元凋亡的影响

目的研究线粒体内膜ATP敏感性钾通道（Mito-KAw）特异性开放剂二氮嗪预处理对缺氧复氧后大鼠海马神经元凋亡的影响。方法取离体培养的大鼠海马神经元，随机分为4组：对照组（A组）、二氮嗪30μmol／L组（B组）、二氮嗪1（30μmol／L组（C组）、二氮嗪100μmol／L＋Mito-KATP特异性阻断剂5．羟葵酸100μmol／L组（D组），各组神经元每天给予相应药物预处理1h，连续3d，继而缺氧4h复氧24h，观察神经元的活力、凋亡率、Bax和Bd．2蛋白的表达水平。结果与其它3组比较，C组海马神经元活力增强，凋亡率降低，Bcl．2蛋白表达水平升高，Bax蛋白表达水平下降（P〈0．01）。结论100μmol／L二氮嗪预处理通过改善Bcl-2与Bax蛋白表达的失衡，降低神经元的凋亡，对大鼠海马缺氧复氧神经元产生了保护效应。     

不同浓度七氟醚预处理对大鼠海马神经元缺氧复氧时细胞凋亡的影响及线粒体ATP敏感型钾通道在其中的作用

目的 探讨不同浓度七氟醚预处理对大鼠海马神经元缺氧复氧时细胞凋亡的影响及线粒体ATP敏感型钾通道(mito-KATP通道)在其中的作用.方法 新生(出生＜24 h)SD大鼠,雌雄不拘,体重5～6 g,原代培养海马神经元,接种于培养孔或培养皿中,采用随机数字表法,将其随机分为7组,每组48孔和12皿,正常对照组(C组):不予任何处理;缺氧复氧组(HR组):缺氧4 h复氧24 h;6%七氟醚预处理组(S1 组)、4%七氟醚预处理组(S2 组)、2%七氟醚预处理组(S3 组):分别经6%、4%、2%七氟醚预处理后行缺氧复氧;5-羟葵酸100 μmol/L预处理组(5-HD组):经mito-KATP通道阻断剂5-羟葵酸(终浓度100 μmol/L)预处理后进行缺氧复氧;5-羟葵酸100 μmol/L+6%七氟醚预处理组(5-HD+S组):同时行5-羟葵酸和6%七氟醚预处理后进行缺氧复氧.各组以上处理结束后,测定神经元活力、凋亡率、Bcl-2和Bax蛋白的表达水平.结果 与C组比较,其余6组海马神经元活力降低,细胞凋亡率升高,Bcl-2和Bax蛋白表达上调(P＜0.01);与HR组比较,S1组～S3组海马神经元活力增强,细胞凋亡率降低,Bcl-2蛋白表达上调,Bax蛋白表达下调(P＜0.01),5-HD组和5-HD+S组上述指标比较差异无统计学意义(P＞0.05);与S1组比较,S2组、S3组和5-HD+S组海马神经元活力降低,细胞凋亡率升高,Bcl-2蛋白表达下调,Bax蛋白表达上调(P＜0.01);与S2组比较,S3组海马神经元活力降低,细胞凋亡率升高,Bcl-2蛋白表达下调,Bax蛋白表达上调(P＜0.01).结论 七氟醚预处理可抑制大鼠海马神经元缺氧复氧时细胞凋亡,从而减轻神经元损伤,且呈浓度依赖性,机制可能与开放神经元mito-KATP通道,上调Bcl-2蛋白表达,下调Bax蛋白表达有关.

Abstract：

Objective To investigate the effect of preconditioning with different concentrations of sevoflurane on hypoxia-reoxygenation(H/R)-induced apoptosis in rat hippocampal neurons and the role of mitochondrial KATP(mito-KATP)channels.Methods Primary cultured hippocampal neurons isolated from newborn SD rats(＜24h)of both sexes,weighing 5-6 g,were randomly divided into 7 groups with 48 wells and 12 dishes in each one:control group(C group),H/R group,preconditioning with 6%,4%and 2% sevoflurane groups(S1-3 groups),5-hydroxydecanoate(5-HD,mito-KATP channel blocker)100 μmol/L preconditioning group(5-HD group)and preconditioning with 5-HD 100 μmol/L+6% sevoflurane group(5-HD+S group).The neurons were exposed to 4 h hypoxia followed by 24 h reoxygenation. In S1-3 groups, preconditioning was performed with 6% , 4% and 2% sevoflurane respectively before H/R. In 5-HD group, preconditioning was performed with 5-HD (final concentration 100 μmol/L) before H/R. In 5-HD + S group, preconditioning was performed with 5-HD 100 μmol/L and 6% sevoflurane before H/R. The neuronal viability, apoptosis rate and expression of Bcl-2 and Bax were determined after 24 h reoxygenation.Results The neuronal viability was significantly lower,while the apoptosis rate and expression of Bcl-2 and Bax were significantly higher in the other 6 groups than in group C(P＜0.01).The neuronal viability and expression of Bcl-2 were significantly higher,while the apoptosis rate and Bax expression were lower in S1-3 groups than in group H/R. There was no significant difference in the parameters mentioned above between 5-HD and 5-HD + S groups(P＞0.05).The neuronal viability and expression of Bcl-2 were significantly lower, while the apoptosis rate and Bax expression were higher in S2, S3 and 5-HD + S groups than in group S1, and in group S3 than in group S2(P＜0.0l) .Conclusion Sevoflurane preconditioning can inhibit H/R-induced apoptosis in rat hippocampal neurons and reduce the injury to neurons in a concentration-dependent manner, and the underlying mechanism may be related to activation of mito-KATP channels, up-regulation of Bcl-2 expression and down-regulation of Bax expression.     

异丙酚不同时机给药对大鼠海马缺氧复氧损伤神经元胞浆细胞色素c的影响

目的 评价异丙酚不同时机给药对大鼠海马缺氧复氧损伤神经元胞浆细胞色素c浓度(Cty c)的影响.方法 原代培养大鼠海马神经元,采用随机数字表法,将其随机分为5组(n=5):对照组(C组)、缺氧复氧损伤模型组(M组)和异丙酚不同时机给药组(Ⅰ组、Ⅱ组和Ⅲ组).采用缺氧6h再复氧的方法制备海马神经元缺氧复氧损伤模型.Ⅰ组、Ⅱ组和Ⅲ组分别于缺氧前、复氧即刻和复氧2 h(T0～2)时加入异丙酚至终浓度20 μmol/L.各组分别于T1,2和复氧24 h(T3)时观察细胞凋亡情况,检测胞浆Cytc的浓度.结果 与C组相比,M组T1-3时、Ⅰ组、Ⅱ组和Ⅲ组T1,2时细胞胞浆Cty c浓度升高(P＜0.05);与M组相比,Ⅰ组T1-3时、Ⅱ组和Ⅲ组T1.2时细胞胞浆Cty c浓度降低(P＜0.05);与Ⅰ组相比,Ⅱ组和Ⅲ组T1,2时细胞胞浆Cty c浓度升高(P＜0.05);与Ⅱ组相比,Ⅲ组T2时细胞胞浆Cty c浓度升高(P＜0.05).不同时机异丙酚给药组细胞凋亡数目较M组明显减少.结论 异丙酚不同时机给药可减少线粒体Cty c释放到胞浆,抑制海马神经元凋亡,减轻缺氧复氧损伤,缺氧前给药效果较好.     

Neuroprotective effects of propofol in models of cerebral ischemia: inhibition of mitochondrial swelling as a possible mechanism

BACKGROUND: Propofol (2,6-diisopropylphenol) has been shown to attenuate neuronal injury in a number of experimental conditions, but studies in models of cerebral ischemia have yielded conflicting results. Moreover, the mechanisms involved in its neuroprotective effects are yet unclear. METHODS: The authors evaluated the neuroprotective effects of propofol in rat organotypic hippocampal slices exposed to oxygen-glucose deprivation, an in vitro model of cerebral ischemia. To investigate its possible mechanism of action, the authors then examined whether propofol could reduce Ca2+-induced rat brain mitochondrial swelling, an index of mitochondrial membrane permeability, as well as the mitochondrial swelling evoked by oxygen-glucose deprivation in CA1 pyramidal cells by transmission electron microscopy. Finally, they evaluated whether propofol could attenuate the infarct size and improve the neurobehavioral outcome in rats subjected to permanent middle cerebral artery occlusion in vivo. RESULTS: When present in the incubation medium during oxygen-glucose deprivation and the subsequent 24 h recovery period, propofol (10-100 microM) attenuated CA1 injury in hippocampal slices in vitro. Ca2+-induced brain mitochondrial swelling was prevented by 30-100 microM propofol, and so were the ultrastructural mitochondrial changes in CA1 pyramidal cells exposed to oxygen-glucose deprivation. Twenty-four hours after permanent middle cerebral artery occlusion, propofol (100 mg/kg, intraperitoneal) reduced the infarct size by approximately 30% when administered immediately after and up to 30 min after the occlusion. Finally, propofol administered within 30 min after middle cerebral artery occlusion was unable to affect the global neurobehavioral score but significantly preserved spontaneous activity in ischemic rats. CONCLUSIONS: These results show that propofol, at clinically relevant concentrations, is neuroprotective in models of cerebral ischemia in vitro and in vivo and that it may act by preventing the increase in neuronal mitochondrial swelling.     

Neuroprotective Effects of Propofol in Models of Cerebral Ischemia: Inhibition of Mitochondrial Swelling as a Possible Mechanism

Background: Propofol (2,6-diisopropylphenol) has been shown to attenuate neuronal injury in a number of experimental conditions, but studies in models of cerebral ischemia have yielded conflicting results. Moreover, the mechanisms involved in its neuroprotective effects are yet unclear.

Methods: The authors evaluated the neuroprotective effects of propofol in rat organotypic hippocampal slices exposed to oxygen-glucose deprivation, an in vitro model of cerebral ischemia. To investigate its possible mechanism of action, the authors then examined whether propofol could reduce Ca2+-induced rat brain mitochondrial swelling, an index of mitochondrial membrane permeability, as well as the mitochondrial swelling evoked by oxygen-glucose deprivation in CA1 pyramidal cells by transmission electron microscopy. Finally, they evaluated whether propofol could attenuate the infarct size and improve the neurobehavioral outcome in rats subjected to permanent middle cerebral artery occlusion in vivo.

Results: When present in the incubation medium during oxygen-glucose deprivation and the subsequent 24 h recovery period, propofol (10-100 [mu]m) attenuated CA1 injury in hippocampal slices in vitro. Ca2+-induced brain mitochondrial swelling was prevented by 30-100 [mu]m propofol, and so were the ultrastructural mitochondrial changes in CA1 pyramidal cells exposed to oxygen-glucose deprivation. Twenty-four hours after permanent middle cerebral artery occlusion, propofol (100 mg/kg, intraperitoneal) reduced the infarct size by approximately 30% when administered immediately after and up to 30 min after the occlusion. Finally, propofol administered within 30 min after middle cerebral artery occlusion was unable to affect the global neurobehavioral score but significantly preserved spontaneous activity in ischemic rats.     

Roles of AKAP1 in high-glucose induced mitochondrial fission in podocytes

Objective To investigate the roles of A kinase anchoring protein1(AKAP1)in high-glucose induced mitochondrial fission in podocytes. Methods Conditionally immortalized human podocytes were cultured in serum-free medium for 24 hours, and then exposed to different glucose concentration conditions in different time periods. The protein expressions of AKAP1 were observed by immunofluorescence, and AKAP1, dynamin related protein1 (Drp1) and phospho Ser 637-Drp1 (p-Drp1) were analyzed by Western blotting. AKAP1 siRNA was transfected to block AKAP1 expression.Podocytes were then divided into normal control group (5 mmol/L glucose), hypertonic group (30 mmol/L mannitol+5 mmol/L glucose), high glucose group (35 mmol/L glucose), and high glucose+AKAP1 siRNA group. Mitochondrial morphological changes were assessed by mitotracker red staining. Podocyte apoptosis was assessed by flow cytometry. Results Compared with normal group, high-glucose induced more podocytes apoptosis (P＜0.05), more mitochondrial fission with decreased aspect ratio and form factor (all P＜0.05). Upregulated AKAP1 protein level, and increased ratio of p-Drp1/Drp1 (all P＜0.05) in time and concentration dependent manners were also observed. Compared with high glucose group, transfection of AKAP1 siRNA showed less apoptosis (P＜0.05), less mitochondrial fission with increased aspect ratio and form factor (all P＜0.05), and down-regulated AKAP1 protein level as well as p-Drp1/Drp1 ratio (all P＜0.05). Conclusion High glucose induced mitochondrial fission might be induced through AKAP1-Drp1 pathway.     

丙泊酚在正颌外科控制性降压中的脑保护作用机理

目的:通过大鼠实验,研究丙泊酚在大鼠脑缺血再灌注损伤时对线粒体通透性转换孔活性的影响程度,及其抑制神经细胞凋亡坏死的作用机制。以探讨其在正颌外科控制性降压中的脑保护作用机理。方法:选取健康雄性大鼠30只,体重250～300g,采用"双侧颈总动脉阻断法"建立前脑缺血再灌注模型,左侧侧脑室于假手术组(C组)、缺血再灌注组(I/R)组注射生理盐水1ml/kg,丙泊酚干预组(P组)射注丙泊酚1mg/kg,24h后断头提取海马组织线粒体,加入CaCl2于37℃下形成钙超载后孵育5min。电镜观察其微观组织形态学改变,采用紫外分光光度计法来观察线粒体通透性转换孔开放程度。结果:电镜下C组线粒体结构完整,排列密集;I/R组可见线粒体明显肿胀、嵴断裂、膜破裂;P组可见线粒体部分肿胀,嵴部分断裂,但损伤程度轻于I/R组。与C组相比较,I/R组和P组线粒体吸光度值明显下降(P<0.05);与I/R相比,P吸光度值下降幅度减小(P<0.05)。丙泊酚组细胞肿胀坏死明显减轻,凋亡细胞及坏死细胞明显减少。结论:丙泊酚能够改善大鼠前脑缺血再灌注后线粒体形态,其机制可能与其抑制线粒体通透性转换孔(MPTP)开放有关,从而改善线粒体功能,抑制神经细胞凋亡坏死,减轻脑缺血再灌注损伤。这说明丙泊酚在正颌外科控制性降压中使用时对大脑有良好的保护作用,可以大幅度提高手术安全效果,具有重要的临床指导意义。     

丙泊酚麻醉三低状态对瓣膜置换术患者30天死亡风险的影响

目的 拟确立影响瓣膜置换患者术后30 d病死率的丙泊酚麻醉三低[低BIS、低MAP和低效应室靶控浓度(target effect-site concentration,Ce)]阈值. 方法 161例择期拟行单纯瓣膜置换术的成年风湿性心脏病患者,BIS监测下行丙泊酚效应室靶控麻醉,术后随访30 d,根据预后不同将患者分为存活组(155例)和死亡组(6例),建立单因素和多因素回归模型分析风险因素. 结果 BIS＜45、MAP＜65 mmHg(1mrmHg=0.133 kPa)、Ce＜1.5 mg/L的积累时间和三低同时出现的累积时间:死亡组[(278±95)、(153±41)、(125±40)、(58±16) min],较存活组[(163±53)、(65±21)、(63±20)、(21±6) min]均明显延长(P＜0.05).单因素回归模型中:有无吸烟史,术前有无合并症,BIS＜45、MAP＜65 mmHg、Ce＜1.5 mg/L的积累时间和三低同时出现的累积时间,平均手术、麻醉和转机时间及术后ICU驻留时间,均是增加30 d病死率的风险因素(P＜0.05).多因素回归分析显示,三低累积时间和ICU驻留时间仍然是增加术后30 d病死率的危险因素(P＜0.05). 结论 丙泊酚麻醉三低状态(BIS＜45、MAP＜65 mmHg和Ce＜1.5mg/L)和ICU驻留时间是增加瓣膜置换患者术后30 d死亡风险的独立因素.     

海马神经细胞线粒体通透性转换孔在富氢液减轻大鼠全脑缺血再灌注损伤中的作用

目的 评价海马神经细胞线粒体通透性转换孔(mPTP)在富氢液减轻大鼠全脑缺血再灌注损伤中的作用.方法 雄性SD大鼠72只,体重250 ～ 300 g,采用随机数字表法,将其随机分为6组(n=12):假手术组(S组)、缺血再灌注组(IR组)、生理盐水组(NS组)、富氢液组(H组)、苍术苷组(A组)和富氢液+苍术苷组(HA组).采用四血管阻塞法建立大鼠全脑缺血再灌注模型,缺血15 min后恢复灌注.H组和HA组于再灌注即刻腹腔注射富氢液5 ml/kg,其余组腹腔注射等容量生理盐水;A组和HA组于再灌注前10 min行侧脑室注射苍术苷15 μl,NS组和H组侧脑室注射等容量生理盐水.再灌注24h时行神经行为学损伤评分后各组随机处死8只大鼠,迅速断头,分离海马神经细胞线粒体,采用分光光度计法测定mPTP的开放程度,Rhodamine123法测定线粒体膜电位.再灌注72 h时各组处死4只大鼠,取海马组织,光镜下观察CA1区病理学结果,计数该区神经细胞存活数.结果 与S组比较,其余组再灌注24h时行为学损伤加重,mPTP活性升高,线粒体膜电位降低(P＜0.05);与IR组比较,H组和HA组再灌注24h时行为学损伤减轻,mPTP活性降低,线粒体膜电位升高(P＜0.05);与H组比较,HA组行为学损伤加重,mPTP活性升高,线粒体膜电位降低(P＜0.05).再灌注72 h时HA组较IR组神经细胞存活数增加(P＜0.05),H组海马CA1区神经元损伤较IR组、NS组、A组和HA组减轻.结论 富氢液可减轻大鼠全脑缺血再灌注损伤,其机制与抑制海马神经细胞mPTP开放,减少线粒体膜电位降低,从而维持线粒体功能有关.     

脑电双频指数指导无痛胃镜检查中瑞芬太尼最适剂量的选择

目的 探讨在无痛胃镜检查中瑞芬太尼复合丙泊酚静脉麻醉时瑞芬太尼的最适剂量.方法 接受无痛胃镜检查患者300例,按照随机数字表法随机双盲分成3组(每组100例):瑞芬太尼1组(R1组,瑞芬太尼0.25 μg/kg)、瑞芬太尼2组(R2组,瑞芬太尼0.5 μg/kg)、瑞芬太尼3组(R3组,瑞芬太尼1.μg/kg).记录各组麻醉前(T0)、置入胃镜时(T1)、退出胃镜时(T2)的BIS值、MAP、HR、SpO2,并记录各组患者丙泊酚用量、术中辅助呼吸和术中体动例数、胃镜检查时间、苏醒时间、术中知晓及术后恶心呕吐的情况、离院时间、离院时眩晕等.结果 3组患者To、T1、T2时BIS值、MAP、HR组间分别比较,差异均无统计学意义(P＞0.05).与R3组比较,R1组、R2组在T1时点SPO2[(96.9±2.1)％、(96.2±2.9)％比(92.1±5.5)％]明显较高,差异有统计学意义(P＜0.05);在T1时点R1组与R2组比较以及T2时点3组分别比较,差异均无统计学意义(P＞0.05).丙泊酚用量R1组[(110±12) mg]、R2组[(65±8)mg]明显多于R3组[(48±6)mg],R1组丙泊酚用量也明显多于R2组,同时术中辅助呼吸R1组(6％)、R2组(9％)较R3组(21％)明显减少,差异均有统计学意义(P＜0.05).与R2组、R3组比较,R1组患者苏醒时间、离院时间明显延长,术中体动及离院时眩晕发生较多(P＜0.05),但R2组、R3组比较差异无统计学意义(P＞0.05).3组患者胃镜检查时间、术中知晓及术后恶心呕吐发生情况比较,差异均无统计学意义(P＞0.05).结论 以0.5 μg/kg瑞芬太尼辅助适量丙泊白酚是胃镜检查中较适合的搭配方案.     

两种浓度丙泊酚用于腹腔镜胆囊切除术患者药物效应比较

目的 比较相同剂量1％丙泊酚与2％丙泊酚用于腹腔镜胆囊切除术患者的药物效应及达到相同药物效应时的药物用量.方法 选择拟行腹腔镜胆囊切除术患者100例,采用随机数字表法分为两组(每组50例):输注1％丙泊酚组(Ⅰ组)、输注2％丙泊酚组(Ⅱ组).诱导剂量均为2 mg/kg,整个麻醉过程中用Narcotrend麻醉深度监护仪监测麻醉深度,诱导完成后根据Narcotrend指数调整两组丙泊酚的泵速.观察患者Narcotrend指数下降到36的时间、意识消失时间、监测诱导开始15 min内MAP和HR下降百分比、丙泊酚第1小时用量及停药至Narcotrend指数恢复到65的时间.结果 两组患者意识消失时间及Narcotrend指数下降到36的时间Ⅰ组分别为(115±45)s和(136±54)s,Ⅱ组分别为(156±60)s和(183±61)s,Ⅰ组短于Ⅱ组(P＜0.05).丙？白酚使用总量和丙泊酚第1小时用量Ⅰ组分别为(41±15)ml和(36±10) ml,Ⅱ组的2倍用药量分别为(53±18) ml和(46±15)ml,Ⅱ组的2倍用药量大于Ⅰ组用药量(P＜0.05).结论 2％丙泊酚麻醉药用量的2倍大于1％丙泊酚,而不是等量的,这说明1％丙泊酚的药效可能强于2％丙泊酚,2％丙泊酚经济效益相对较低.