硫化氢对氧应激下大鼠肝星状细胞的收缩和黏附作用

目的 探讨硫化氢(H2S)含量的变化对氧应激下大鼠肝星状细胞(HSC)收缩和黏附作用影响.方法 将HSC分为空白组(B组,HSC-T6);对照组(C组,HSC-T6+ 500μ mol/L FeN-TA);NaHS组(N组,N1:HSC-T6+500μmol/L FeNTA+100μmol/L NaHS;N2:HSC-T6+500μmol/L FeNTA+200μmol/L NaHS;N3:HSC-T6 +500μmol/L FeNTA+ 300μ mol/LNaHS;N4:HSC-T6 500μmol/L FeNTA+ 400μmol/LNaHS);GLBN组(G组,G1:HSC-T6+ 500μmol/L FeNTA+ 200 μmol/LGLBN;G2:HSC-T6+ 500μmol/L FeNTA+ 400μmol/LGLBN).应用500 μmol/L次氮基三乙酸铁(FeNTA)制备氧应激模型.采用聚硅酮膜法直观检测氧应激模型大鼠肝星状细胞收缩情况、甲苯胺兰染色法测定细胞黏附率、Boyden Chamber小室法测定HSC跨膜迁移数量.给予不同浓度的外源性H2S供体NaHS和KATP通道阻断剂格列本脲(GLBN),在不同刺激条件下,观察上述指标.结果 HSC被NaHS处理后可见聚硅酮膜由于细胞收缩而引起明显皱纹,能够明显促进HSC收缩,而且随H2S浓度的升高和作用时间的延长,HSC收缩程度增强,这些作用能够被格列本脲阻止.加入200、400 μmol/L H2S的HSC黏附抑制率分别为62.4％、81.7％,与对照组相比有显著差异;100、200、300、400 μmol/L 4种不同浓度NaHS的HSC细胞迁移数量为6.43×103、8.85×103、11.34×103、14.86×103,与对照组(2.52×103)比较存在显著差异.结论 H2S在氧化应激下能促进HSC的收缩.H2S通过抑制细胞黏附、增加HSC跨膜迁移数量发挥细胞保护作用.     

抗心律失常肽对蛋白激酶C激动剂致心律失常作用的影响

目的 观察抗心律失常肽对蛋白激酶C激动剂致心律失常作用的影响并探讨其作用机制.方法 制备左室楔形心肌块灌注模型,随机分为①正常组;②佛波酯(PMA)组:PMA 0.5 μmol/L;③抗心律失常肽(AAP10)组:PMA 0.5 μmol/L +AAP10 0.5 μmol/L.同步记录心内膜、心外膜心肌细胞跨膜动作电位及跨室壁心电图,给予程序性期前刺激诱发室性心动过速(室速)的发生.通过免疫印迹法(Western blot)检测心肌细胞缝隙连接蛋白43(Cx43)总量及其 S368位点去磷酸化水平的变化.结果 与正常对照组相比,PMA组QT间期[(260±25) ms vs.(302±21) ms,P＜0.01]显著缩短,Tp-e(同一心搏T波顶点至终点的间期)[(61±13) ms vs.(51±7) ms,P＜0.01]及Tp-e/QT[(0.24±0.05) vs.(0.17±0.02),P＜0.01]显著增大,Cx43的总量(P＜0.05)及 S368位点去磷酸化水平(P＜0.01)显著减少,室速诱发率(70% vs.0%,P＜0.05)明显增加.与PMA组相比,AAP10组QT间期[(241±22) ms vs.(260±25) ms,P＞0.05]及S368位点去磷酸化水平(P＞0.05)无明显改变,但Cx43的总量(P＜0.05)明显增加,Tp-e[(41±6) ms vs.(61±13) ms,P＜0.01]及Tp-e/QT[(0.17±0.03) vs.(0.24±0.05),P＜0.01]显著减小,且室速诱发率(20% vs.70%,P＜0.05)明显降低. 结论 AAP10通过阻止PMA对缝隙连接的下调而减少PMA诱导的兔室性心律失常的发生.     

表达心脏SCN5A基因的人胚肾细胞钠电流特性及其对钠通道阻滞剂的反应性

目的 利用人胚肾293细胞表达心脏钠通道SCN5A基因并研究其钠电流特性和对钠通道阻滞剂的反应性.方法 野生型SCN5A基因和SCN1B基因共表达于人胚肾293细胞,应用全细胞膜片钳技术记录给药(氟卡尼与利多卡因)前后的钠电流.结果 SCN5A基因转染效率约为60%;测试电压为-40 mV时记录到钠电流峰值大小约为-8 nA;100 μmol/L的氟卡尼轻度抑制钠电流,使钠电流峰值减少(21.1±4.6)%[(-435.8±30.5) pA/pF vs.(-343.9±27.1) pA/pF,P＜0.01];氟卡尼使钠通道激活曲线和失活曲线均呈负向移动,改变的幅值分别是-6.08 mV[(-51.88±1.20) mV vs.(-57.96±0.79) mV,P＜0.05]和-9.08 mV[(-94.12±0.13) mV vs.(-103.20±0.11) mV,P＜0.05];1 Hz和10 Hz频率刺激时,氟卡尼使钠电流分别减少(64.5±10.7)%和(83.5±12.2)%(P＜0.01);30 μmol/L利多卡因使钠通道失活后快恢复时间常数和慢恢复时间常数分别延长2倍和3倍.结论 表达心脏钠通道SCN5A基因的人胚肾293细胞模型可用于基因特异性的钠通道阻滞剂安全性与药效学筛查.     

钩藤碱抑制麻醉大鼠颈动脉窦压力感受性反射的研究

目的 研究钩藤碱(Rhy)对颈动脉窦压力感受性反射(CSB)的作用并探讨其作用机制.方法 利用隔离灌流大鼠颈动脉窦技术,确定各项功能参数,如阈压(TP)、饱和压(SP)、平衡压(EP)、工作范围(OR)、最大斜率(PS)和平均动脉压反射性下降幅度(RD)等.Rhy(10、50、100 μmol/L)溶于K-H液后灌流窦区,以斜坡方式升降窦内压来观察Rhy对CSB的影响.分别预先灌流一氧化氮合酶抑制剂L-NAME,钾通道阻断剂四乙铵(TEA)和L-型钙通道开放剂Bay K8644后再给予Rhy,观察它们对Rhy作用的影响.结果 Rhy浓度依赖性地抑制了CSB, 使其各功能参数改变, TP和SP增大,PS和RD均减小.Rhy的抑制作用不能被L-NAME(300 μmol/L)和 TEA(1 mmol/L)预处理所取消,而可被Bay K8644 (500 nmol/L)明显减弱.结论 Rhy抑制了CSB,此作用可能是通过减弱压力感受器的牵张敏感性离子通道的钙内流来实现,而与NO和钾通道无关.     

硫化氢对豚鼠主动脉前庭自律细胞电生理的影响及其机制

目的:探讨硫化氢(H_2S)对豚鼠主动脉前庭慢反应自律细胞电生理特性的影响及其机制。方法:采用标准微电极细胞内采集技术,观察不同浓度的硫化氢对主动脉前庭自律细胞电生理的影响。结果:(1)胱硫醚-γ裂解酶(cystathionineγ-lyase, CSE)的不可逆抑制剂DL-propargylglycine (PPG, 200μmol/L)使主动脉前庭自律细胞的Vmax、RPF和VDD加快,APA增大(P<0.05,CBS合成酶抑制剂氨基氧乙酸(aminooxyacetate acid,AOAA), 100μmol/L)对主动脉前庭自律细胞无影响。(2)50、100和200μmol/L NaHS的浓度依赖性使主动脉前庭自律细胞的RPF和VDD减慢、Vmax、APA减小(P<0.05)。(3)ATP敏感性钾通道(KATP)阻断剂格列苯脲(glybenclamide, Gli, 20μmol/L)可部分阻断NaHS的电生理效应(P<0.05)。(4) L型钙通道激动剂Bay K 8644可部分阻断NaHS的电生理效应。结论:主动脉前庭自律细胞有CSE催化产生的内源性H_2S的生成。H_2S对主动脉前庭自律细胞有负性变时变传导作用,其机制与开放KATP通道抑制L-Ca~(2+)通道有关。     

KATP通道激动剂吡那地尔对哇巴因诱发大鼠离体心脏心律失常的影响

目的 应用哇巴因在大鼠离体心脏建立稳定的心律失常模型,观察KATP通道激动剂吡那地尔(pinacidil)对哇巴因诱发心律失常的影响. 方法 采用健康成年SD大鼠建立离体心脏Langendorff主动脉逆行灌流系统.实验分5组:正常对照组,哇巴因模型组和吡那地尔1,3,10 μmol/L干预组.每组8只动物.应用5 μmol/L哇巴因和低K+台式液([K+]o=2.7 mmol/L)灌流心脏诱发室性心律失常,分别观察1,3,10 μmol/L吡那地尔对药物性心律失常的影响,全程记录心电图的变化. 结果在正常台式液中加入5 μmol/L哇巴因灌流大鼠离体心脏仅引起一过性心律失常,而降低台式液中KCl浓度(2.7 mmol/L),则相同浓度哇巴因可诱发出稳定的室性心律失常,包括室性早搏、室速和室颤.给药30 min内,期前收缩(PVB)达到(386±49)个,室速(VT)和室颤(VF)发生率分别为100%(8/8)和87.5%(7/8)(n=8,P<0.01).待哇巴因诱发出心律失常后立即应用吡那地尔可浓度依赖性抑制哇巴因诱发的期前收缩,降低室速和室颤的发生率(n=8,P<0.01). 结论作为KATP通道激动剂,1-10 μmol/L吡那地尔可拮抗哇巴因所致心律失常,其电生理机制可能为增大心肌外向离子流,缩短动作电位时程并使心肌细胞膜超极化.     

缺氧及谷氨酸对大鼠海马神经元NMDA通道的影响

目的 观察大鼠海马神经元模拟缺血缺氧时谷氨酸诱发电流的改变,研究缺氧和谷氨酸对大鼠海马神经元N-甲基-D-天门冬氨酸(N-methyl-D-aspartic acid,NMDA)通道开放动力学的影响,为中枢神经损伤的康复提供理论依据.方法 实验分为6组;①对照组通氧 20μmol/LL-Glu 1.0μmol/L Gly;②组1通氧 50μmol/LL-Glu 1.0 μmol/L Gly;③组2通氧 100 μmol/L L-Glu 1.0 μmol/L Gly;④组3通氧 200μmol/L L-Glu 1.0μmol/L Gly;⑤组4缺氧 20 μmol/L L-Glu 1.0μmol/L Gly;⑥组5缺氧 20 μmol/L L-Glu 1.0μmol/L Gly 30 μmol/L MK-801.以原代培养的大鼠海马神经元为标本,运用膜片钳技术的细胞吸附式方法记录NMDA通道的单通道电流.结果 在急性缺氧条件下,NMDA通道的开放时间常数τ1,τ2较对照组延长,分别由(0.47±0.12)ms,(5.42±0.33)ms变为(1.02±0.17)ms,(7.47±0.93)ms;关闭时间常数τ1,τ2较对照组明显缩短,分别由(21.13±4.21)ms,(167.83±23.23)ms变为(6.54±1.44)ms,(21.32±2.87)ms;平均开放概率增大,由0.17±0.11变为0.79±0.32,差异有显著意义(P＜0.05).谷氨酸浓度增加时,NMDA通道开放时间常数增大,关闭时间常数减小,开放概率增大.结论 缺氧及谷氨酸能提高海马神经元NMDA通道的兴奋性,促进NMDA通道开放增加.     

人神经母细胞瘤SK-N-SH细胞Ca2+通道的电生理特性

目的研究人神经母细胞瘤SK-N-SH细胞L型Ca2+通道的特性及其激动剂BayK 8644对通道的影响.方法培养SK-N-SH细胞,用膜片钳细胞贴附式技术记录和研究L型Ca2+通道的特性.结果SK-N-SH细胞L型Ca2+通道电导为(27.8±2.56)pS,平均开放时间为(0.65±0.08)ms,平均关闭时间的短关闭时间常数(0.53±0.05)ms,长关闭时间常数(6.02±3.46)ms.Bay K 8644使Ca2+通道平均开放时间延长(P＜0.05),但不影响其电导(P＞0.05).结论人神经母细胞瘤SK-N-SH细胞上存在L型Ca2+通道,与其他神经元上L型Ca2+通道特性相近.     

硫化氢对急性肺损伤大鼠肺组织核转录因子κB及细胞间黏附分子1表达的影响

目的 探讨硫化氢(H2S)对油酸诱导的急性肺损伤(ALI)大鼠肺组织核转录因子κB(NF-κB)与细胞间黏附分子1(ICAM-1)表达的影响.方法 雄性SD大鼠42只,采用随机数方法分为对照组(6只)、油酸组及油酸+硫氢化钠(NaHS)组,后2组大鼠分别在2、4、6h3个时间点进行观察,每个时间点大鼠为6只.复制大鼠ALI模型,对照组大鼠经过尾静脉注射0.1 ml/kg生理盐水;油酸组大鼠通过尾静脉注射油酸0.1 ml/kg;油酸+NaHS组大鼠先腹腔注射NaHS 56 μmol/kg(溶于0.5 ml生理盐水),30 min后经大鼠尾静脉注射油酸0.1 ml/kg.对支气管肺泡灌洗液沉渣行瑞士染色进行白细胞分类计数;对大鼠肺组织病变进行半定量肺损伤评分;测定肺组织中H2S的含量;应用免疫组织化学法对肺泡上皮细胞中ICAM-1表达进行定位及半定量分析,并对NF-κB核转位进行半定量分析.结果 油酸组大鼠2、4、6h支气管肺泡灌洗液多形核白细胞(PMN)比例[(74.5±3.0)％、(80.2±2.0)％和(87.2±2.7)％]及肺损伤评分(5.2±0.8、6.4±0.6和6.8±0.8)均明显高于对照组[(3.1±1.6)％和0.4±0.6,均P＜0.01];肺组织中H2S含量均明显低于对照组[ (21.20 ±0.38) μmol/g、( 20.80±0.53)μmol/g、(18.92±0.75)μmol/g比(26.81±0.65)μmol/g,均P＜0.01];肺泡上皮细胞中NF-κB核表达和ICAM-1胞膜表达则均明显高于对照组(均P＜0.05).油酸+NaHS组支气管肺泡灌洗液PMN比例及肺损伤评分在2、4和6h3个时间点均明显低于油酸组(均P＜0.05);肺组织中H2S含量在4和6h明显高于油酸组(均P＜0.05);肺泡上皮细胞中NF-κB核表达和ICAM-1胞膜表达在4和6h则明显低于油酸组相应时间点(均P＜0.05).结论 H2S可能通过抑制ALI大鼠肺部炎症反应发挥保护效应,其抗炎效应与其抑制大鼠肺泡上皮细胞NF-κB的表达有关.     

姜黄素对乳腺癌细胞顺铂敏感性的影响

目的 探讨姜黄素(curcumin)对乳腺癌细胞中顺铂(Cisplatin,CDDP)治疗敏感性的影响及其可能机制.方法 CCK-8检测、Hoechst染色观察CDDP、姜黄素单独及联合用药48 h对MCF7细胞增殖抑制和细胞凋亡的影响;Western blot分析MCF7细胞在CDDP(0、1.25、2.5、5、10、20 μg/mL)、姜黄素(0、1、5、20、30、50、100 μmol/L)单独及联合处理后FEN1(flap endonuclease 1)表达水平的变化;CCK-8检测沉默FEN1对MCF7细胞中CDDP敏感性的影响.结果 CDDP、姜黄素均可以剂量依赖方式抑制MCF7细胞增殖,其IC50分别为5、30 μmol/L;与单独2μg/mLCDDP处理组比较,2μg/mL CDDP联合20-μmol/L姜黄素、30 μmol/L姜黄素处理组对细胞增殖的抑制效应明显增强[分别为(84.1±0.8)％、(51.1±0.5)％、(29.4±0.3)％,P＜0.05];与单独20μmol/L姜黄素处理组比较,20 μmol/L姜黄素联合2μg/mL CDDP、5μg/mL CDDP处理组对细胞增殖的抑制效应也明显增强[分别为(76.9±0.7)％、(42.4±0.3)％、(31.6±0.4)％,P＜0.05];2μg/mL CDDP联合20 μmol/L姜黄素组的细胞凋亡明显增强(P＜0.05);与Control siRNA组比较,FEN1 siRNA+CDDP组可显著增强CDDP抑制MCF7细胞增殖的敏感性[(25.4±0.3)％vs(18.7±0.2)％,P＜0.05];CDDP增殖抑制无效浓度或低浓度时,FEN1蛋白的表达随CDDP的处理剂量依赖性上调,而姜黄素可剂量依赖性下调FEN1蛋白表达;与单独CDDP和姜黄素处理组比较,2μg/mL CDDP联合20 μmol/L姜黄素组可显著降低FEN1蛋白表达(P＜0.05).结论 姜黄素可增强CDDP对乳腺癌细胞的敏感性,其机制与降低细胞FEN1的表达有关.     

硫化氢对家兔肠系膜动脉血管环张力调节研究

目的:观察硫化氢(H2S)对家兔肠系膜血管环张力的调节作用,及其可能的作用机制。方法:应用离体血管环张力测定技术,用金属钩将3mm左右的动脉环悬置于含K-H液的离体器官浴槽中,观察硫化氢在血管环张力的作用,由计算机生物信号采集处理系统进行记录分析,检测血管环张力的变化,制作浓度反应曲线。结果:(1)外源性的NaHS(H2S的供体)可以剂量依赖性地舒张由氯化钾(KCL)预收缩的肠系膜动脉血管环。(2)用ATP敏感性钾通道(KA T P)通道阻断剂格列苯脲(Gli)、钙通道的开放剂1,4-二氢-2,6-二甲基-5-硝基-4-(2-[三氟甲基]苯基)吡啶-3-羧酸甲酯(Bay K8644)、NO合酶的抑制剂左旋硝基精氨酸甲酯(L-NAME)和环氧合酶阻断剂吲哚美辛预处理以及去除血管内皮后,H2S的舒张效应均被显著抑制,浓度反应曲线均明显右移。(3)给予鸟苷酸环化酶的抑制剂1H-(1,2,4)恶二唑(4,3-α)喹喔啉-1-酮(ODQ)预处理后,对H2S的舒张作用没有显著改变。结论:H2S在50～800μmol/L之间浓度依赖性的舒张家兔肠系膜动脉,部分是通过开放KA T P通道和关闭L型钙通道实现的,但与3ˊ,5ˊ-环一磷酸鸟苷(cGMP)途径无关。此作用是内皮依赖性的,且与一氧化氮(NO)和前列环素(PGI2)具有协同作用。     

Electrophysiological effects of hydrogen sulfide on human atrial fibers

Background  It has been reported that endogenous or exogenous hydrogen sulfide (H₂S) exerts physiological effects in the vertebrate cardiovascular system. We have also demonstrated that H₂S acts as an important regulator of electrophysiological properties in guinea pig papillary muscles and on pacemaker cells in sinoatrial nodes of rabbits. This study was to observe the electrophysiological effects of H₂S on human atrial fibers.

Methods  Human atrial samples were collected during cardiac surgery. Parameters of action potential in human atrial specialized fibers were recorded using a standard intracellular microelectrode technique.

Results  NaHS (H₂S donor) (50, 100 and 200 μmol/L) decreased the amplitude of action potential (APA), maximal rate of depolarization (V_max), velocity of diastolic (phase 4) depolarization (VDD) and rate of pacemaker firing (RPF), and shortened the duration of 90% repolarization (APD₉₀) in a concentration-dependent manner. ATP-sensitive K⁺ (K_ATP) channel blocker glibenclamide (Gli, 20 μmol/L) partially blocked the effects of NaHS (100 μmol/L) on human atrial fiber cells. The L-type Ca²⁺ channel agonist Bay K8644 (0.5 μmol/L) also partially blocked the effects of NaHS (100 μmol/L). An inhibitor of cystathionine γ-lyase (CSE), DL-propargylglycine (PPG, 200 μmol/L), increased APA, V_max, VDD and RPF, and prolonged APD₉₀.

Conclusions  H₂S exerts a negative chronotropic action and accelerates the repolarization of human atrial specialized fibers, possibly as a result of increases in potassium efflux through the opening of K_ATP channels and a concomitant decrease in calcium influx. Endogenous H₂S may be generated by CSE and act as an important regulator of electrophysiological properties in human atrial fibers.

     

线粒体KATP在吡那地尔预处理后失血性休克大鼠组织血流灌注和线粒体功能保护效应中的作用

目的 观察吡那地尔(pinacidil)预处理对失血性休克大鼠血流灌注和线粒体功能的保护效应,及其与线粒体ATP激活钾通道[adenosine triphosphate(ATP)-activated potassium channels,KATP]的关系.方法 Wiser大鼠60只,随机数字表法分为:正常对照组、休克组...     

Effects of benzyltetrahydropalmatine on delayed afterdepolarization and Triggered activity and on his-bundle Electrogram and ECG in animal experiment

Summary Standard microelectrode techniques were used to study the effects of benzyltetrahydropalmatine (BTHP) on ouabain-induced delayed afterdepolarization (DAD) and triggered activity in isolated guinea papillary muscles. The results indicate that ouabain-induced DAD and triggered activity were abolished by BTHP 100 μmol/L. In anesthetized rabbit ECG heart rate was reduced in a dose-dependent manner from control value of 288±14 to 261±14 (BTHP 5 mg/kg) and 226±36 bpm (BTHP 10 mg/kg). P-R interval was prolonged. In His-bundle electrogram, H-V interval and V duration were not affected, but A-H interval was prolonged from 41±3 to 45±5 ms.     

Interplay of hydrogen sulfide and nitric oxide on the pacemaker activity of interstitial cells of cajal from mouse small intestine

We studied whether nitric oxide (NO) and hydrogen sulfide (H(2)S) have an interaction on the pacemaker activities of interstitial cells of Cajal (ICC) from the mouse small intestine. The actions of NO and H(2)S on pacemaker activities were investigated by using the whole-cell patch-clamp technique and intracellular Ca(2+) analysis at 30℃ in cultured mouse ICC. Exogenously applied (±)-S-nitroso-N-acetylpenicillamine (SNAP), an NO donor, or sodium hydrogen sulfide (NaHS), a donor of H(2)S, showed no influence on pacemaker activity (potentials and currents) in ICC at low concentrations (10 μM SNAP and 100 μM NaHS), but SNAP or NaHS completely inhibited pacemaker amplitude and pacemaker frequency with increases in the resting currents in the outward direction at high concentrations (SNAP 100 μM and NaHS 1 mM). Co-treatment with 10 μM SNAP plus 100 μM NaHS also inhibited pacemaker amplitude and pacemaker frequency with increases in the resting currents in the outward direction. ODQ, a guanylate cyclase inhibitor, or glibenclamide, an ATP-sensitive K(+) channel inhibitor, blocked the SNAP+NaHS-induced inhibition of pacemaker currents in ICC. Also, we found that SNAP+NaHS inhibited the spontaneous intracellular Ca(2+) ([Ca(2+)](i)) oscillations in cultured ICC. In conclusion, this study describes the enhanced inhibitory effects of NO plus H(2)S on ICC in the mouse small intestine. NO+H(2)S inhibited the pacemaker activity of ICC by modulating intracellular Ca(2+). These results may be evidence of a physiological interaction of NO and H(2)S in ICC for modulating gastrointestinal motility.     

Hydrogen sulfide facilitates carotid sinus baroreceptor activity in anesthetized male rats

Background It has been reported that hydrogen sulfide (H(2)S) could relax vascular smooth muscle by direct activation of K(ATP) channels and hyperpolarization of the membrane potential. Recently, our study has shown that H(2)S facilitated carotid baroreflex. This study was conducted to investigate the effect of H(2)S on carotid baroreceptor activity (CBA). Methods The functional curve of carotid baroreceptor (FCCB) was constructed and the functional parameters of carotid baroreceptor were measured by recording sinus nerve afferent discharge in anesthetized male rats with perfused isolated carotid sinus. Results H(2)S (derived from NaHS) 25, 50 and 100 μmol/L facilitated CBA, which shifted FCCB to the left and upward. There was a marked increase in peak slope (PS) and peak integral value of carotid sinus nerve charge (PIV) in a concentration-dependent manner. Pretreatment with glibenclamide (20 μmol/L), a K(ATP) channel blocker, the above effects of H(2)S on CBA were abolished. Pretreatment with Bay K8644 (an agonist of calcium channels, 500 nmol/L) eliminated the role of H(2)S on CBA. An inhibitor of cystathionine γ-lyase (CSE), DL-propargylglycine (PPG, 200 μmol/L) inhibited CBA in male rats and shifted FCCB to the right and downward.Conclusions Our results suggest that exogenous H(2)S exerts a facilitatory role on isolated CBA through opening K(ATP) channels and further closing the calcium channels in vascular smooth muscle. Endogenous H(2)S may activate CBA in vivo.     

硫化氢在大鼠肝星状细胞氧应激中的作用

目的利用铁超载的方法在体外复制肝纤维化的氧应激模型，给予H2S供体硫氢化钠（NaHS）和内源性H2S作用的KATP通道阻滞剂格列苯脲（GLBN），论证氧应激下硫化氢对HSC细胞具有保护作用的假说。方法将HSC—T6分为8组：空白组、对照组、NaHS组（分为3个浓度组）、格列苯脲组（分为3个浓度组）。用CCK-8试剂盒测定HSC细胞增殖情况；用MDA试剂盒测定上清液MDA（丙二醛）含量；用SOD（超氧化物歧化酶）试剂盒测定上清液和裂解液中SOD活力；用RT—PCR试剂盒检测p38基因表达水平。结果1．Fe—NTA能够促进HSC的增殖，使p38基因表达水平降低、SOD活性降低、MDA浓度提高。对照组和空白组有明显差异（P〈0．05）；2．给予NaHS处理后，细胞增殖减慢，上清液中MDA含量下降，上清液、裂解液中SOD活性提高，p38基因表达水平增高（P〈0．05）；3．给予GLBN处理后，各项指标结果与给予NaHS处理后结果相对应，各组与对照组比较均有明显差异（P〈0．05）。结论氧应激下硫化氢对HSC细胞具有保护作用，可抑制肝纤维化的发生发展。     

Hydrogen sulfide defends against the cardiovascular risk of Nw-nitro-L-argininemethyl ester-induced hypertension in rats via the nitric oxide/endothelial nitric oxide synthase pathway

Background Dyslipidemia caused by liver injury is a significant risk factor for cardiovascular complications.Previous studies have shown that hydrogen sulfide （H2S） protects against multiple cardiovascular disease states in a similar manner as nitric oxide （NO）,and NO/endothelial nitric oxide synthase （eNOS） pathway is the key route of NO production.The purpose of this study was to investigate whether H2S can ameliorate the high blood pressure and plasma lipid profile in Nw-nitro-L-argininemethyl ester （L-NAME）-induced hypertensive rats by NO/eNOS pathway.Methods Thirty-six 4-week old Sprague-Dawley （SD） male rats were randomly assigned to 6 groups （n=6）：control group,L-NAME group,control ＋ glibenclamide group,control ＋ NaHS group,L-NAME ＋ NaHS group,and L-NAME ＋ NaHS ＋ glibenclamide group.Measurements were made of plasma triglycerides （TG）,low-density lipoprotein （LDL）,high-density lipoprotein （HDL）,total cholesterol （CHO）,glutamic-pyruvic transaminase （ALT） levels after 5 weeks.Then measurements of NO level and proteins expression of eNOS,P-eNOS,AKT,P-AKT were made in liver tissue.Results After 5 weeks of L-NAME treatment,the blood pressure,plasma TG （（1.22±0.12） mmol/L in L-NAME group vs.（0.68±0.09） mmol/L in control group; P ＜0.05） and LDL （（0.54±0.04） mmol/L in L-NAME group vs.（0.28±0.02） mmol/L in control group; P ＜0.05） concentration were significantly increased,and the plasma HDL （（0.26±0.02） mmol/L in L-NAME group vs.（0.69±0.07） mmol/L in control group; P ＜0.05） concentration significantly decreased.Meanwhile the rats treated with L-NAME exhibit dysfunctional eNOS,diminished NO levels （（1.36±0.09） mmol/g protein in L-NAME group vs.（2.34±0.06） mmol/g protein in control group; P ＜0.05） and pathological changes of the liver.H2S therapy can markedly decrease the blood pressure （（37.25±4.46） mmHg at the fifth week; P ＜0.05）,and ameliorate the plasma TG （（0.59±0.06） mmHg）,     

氧化应激下大鼠肝星状细胞增殖情况及硫化氢含量的变化

目的了解氧化应激（Oxidative stress）下肝星状细胞（Hepaticstellate cell,HSC）的增殖情况以及细胞中硫化氢（Hydrogen sulphide,H2S）含量的变化,初步探讨H2S在肝纤维化（Hepatic fibrosis）中的作用。方法利用铁超载体外培养细胞的氧化应激模型,给予不同浓度的外源性H2S供体NaHS和KATP通道阻断剂格列本脲（glibenclamide,GLBN）,用MTT检测各组细胞的生长曲线;用敏感硫电极检测各组细胞上清液中H2S含量的变化。结果给予FeNTA后HSC增殖,其OD值随着NaHS浓度的增加和时间的延长而下调;给予GLBN后细胞增殖情况与前者相反;细胞增殖下调时细胞上清液和裂解液中的H2S含量升高,细胞增殖上调时H2S含量降低。结论H2S在氧化应激下能抑制HSC增殖,具有细胞保护作用。