Action Mechanism Research of Lanthanons to Slow Vacuolar Ion Channels in Raphanus Satirus L.(Xinlimei) Radish by Patch-Clamp

We used whole-vacuolar patch-clamp recording mode to study the action mechanism of La3+ to Slow Vacuolar (SV) channels for the first time. We recorded SV channel currents of Xinlimei (Raphanus satirus L.) vacuolars. The minimum activation potentials of voltage-dependent SV channels tied in 25+/-5 mV. The increase in cytoplasmic Ca2+ led to enhancement of SV-type currents. It was found that the threshold potential of activation shifted towards more depolarized values whenever cytoplasmic Ca2+ was increased. When 10(-10) mol/L free La3+ was added to the bath, SV-type current was suppressed by 60 similar to 75%. These data showed La3+ reduced ion permeabilities of Xinlimei root vacuolar membrane.

Study of Oligonucleotide Fixation on Bilayer Lipid Membranes by Patch-clamp Pipette Support

One kind of novel BLMs was fabricated by patch-clamp pipette technology characterized in considerably sensitive to changes of electrochemical parameters.Detectiye currents and voltage presented linear relationship when BLMs was formed and it could be confirmed by Gramicidin method.Ion current was increased by dihexyl (C_ (12)) modified ssDNA fixed on the BLMs and also indicated linear relationship to ssDNA's concentration due to the interaction of (C_ 12)-ssDNA and BLMs.Further more,the regression equations were different from BLMs fixed with ssDNA probe and a blank control BLM in the same experimental conditions.The ssDNA probe was successfully fixed on patch-clamp pipette supported-BLMs.Based on our studies,a biosensor with reactive element of patch-clamp pipette-supported BLMs has been established.

A patch-clamp study on human sperm Cl^- channel reassembled into giant liposome

Aim: To record the single-channel currents and characterize the electrophysiological properties of the Cl^- channels inhuman sperm membrane. Methods: The membrane proteins extracted from the human sperm were reassembled intoliposome bilayer, and the liposomes were fused into giant liposomes with a diameter more than 10μm by dehydration-rehydration procedure. The giant liposomes were used to study the Cl^- channel activities by patch-clamp technique.Results: By patch clamping the giant liposome in an asymmetric NMDG (N-methyl-D-glucamine)-Cl (bath 100//pipette 200 mmol/L) solution system, three kinds of single-channel events with unit conductances of (74.1 ± 8.3) pS,(117.0±5.7) pS and (144.7±4.5) pS, respectively, were detected. Their activities were voltage-dependent and allwere blocked by SITS (4-acetamido-4'-isothiocyanato-stilbene-2', 2'-disulfonic acid) in a concentration-dependentmanner. By constructing the open and close dwell time distribution histograms and then fitting them with exponentialfunction, two time constants were obtained in both the open and the close states. The burst activity and conductancesubstate of the channels were observed. Conclusion; There exist three kinds of Cl^- channels with different conduc-tance in human sperm membrane at least. (Asian J Androl 2001 Sep; 3: 185 - 191)

膜片钳技术10年发展:基于CiteSpace和VOSviewer的可视化分析

背景:膜片钳技术作为研究离子通道的“金标准”,已有40多年的发展历史。然而,科研机构的研究内容相对独立,没有对现有研究成果进行系统总结,导致现有研究存在重复性高、创新性弱的现象。因此,急需对膜片钳技术做一个全面的回顾,以明晰现今的研究现状、热点和未来发展方向。目的:总结近10年膜片钳技术领域的研究现状和发展趋势。方法:使用Web of Science核心合集数据库收集了2013-2023年关于膜片钳技术的出版物。采用CiteSpace和VOSviewer软件对出版物数量进行量化分析,并分析文献条目网络,包括国家、机构、期刊、作者、关键词、高被引文献和共被引参考文献。结果与结论:①近10年间,膜片钳技术领域研究已逐步进入稳定发展阶段。②中国和美国是这方面的领先国家,中国科学院是具有核心影响力的机构,《Journal of Neuroscience》是主要出版刊物,PARK,WON SUN团队(韩国全北国立大学)和CHU,LI团队(中国河北省心脑血管病中医药防治研究重点实验室)在该领域作出了杰出的贡献,但团队之间的协作与交流较少,尚未形成网络合作模式。③膜片钳技术主要应用在神经系统的电生理特性及其疾病的病理机制方面,是研究人员持续关注的焦点。④在心血管系统电生理特性及其疾病病理机制的研究方面,对原代心肌细胞、诱导多能干细胞衍生的心肌细胞的电生理特性和心房颤动、心脏毒性、心源性猝死和高血压等心血管疾病的病理机制方面的研究,是近几年来研究的热点。⑤在膜片钳技术与其他生物技术的结合应用方面,关注的是与光遗传学、双光子钙成像等技术的交叉融合,将是一个重要的研究方向。⑥在药物筛选及治疗靶点的识别研究方面,尤其对于膜片钳技术和中药复方的研究,将成为未来组分中药研究中的一大助力。

Study of transmembrane La^(3+) movement in rat ventricular myocytes by the patch-clamp technique

We have studied transmembrane La3+ movement in rat ventricular myocytes for the first time by using the whole-cell patch-clamp recording mode. La3+ (0.01-5.0 mmol/L) could not bring out inward currents through the L-type calcium channel in rat ventricular myocytes, while it could enter the cells by the same way carried by 1μmo1/L ionomycin. When the outward Na+ concentration gradient is formed, La3+ can enter the cells via Na-Ca exchange, and the exchange currents increase with the increase of external La3+ concentrations. But compared with Na-Ca exchange currents in the same concentration, the former is only 14%-38% of the latter. The patch-clamp experiment indicates that La3+ normally can not enter ventricular myocytes through L-type calcium channel, but it can enter the cells via Na-Ca exchange.

Effects of BaCl_2 on slow vacuolar ion channels on radish by patch-clamp

The effects of BaCl_2 on slow vacuolar (SV) currents of radish are studied byusing the whole-vacuolar patch-clamp recording mode. The Ca^(2+)-dependent SV channel can beactivated by cytosolic Ca^(2+). When 1 mmol/L BaCI_2 is added into pipette solution, SV currents aresuppressed remarkably. Then adding BaCI_2 of different concentrations into the bath solution, SVcurrents reflect different effects. The results show that BaCl_2 with a lower concentration (< 3mmol/L) promotes the channel currents and the currents are saturated when BaCl_2 concentrations arebetween 1 μmol/L and 1 mmol/L, but BaCl_2 with higher concentration (≥ 3 mmol/L) inhibits SVcurrents.

Design and fabrication of a planar patch-clamp substrate using a silicon-on-insulator wafer

The planar patch-clamp technique has been applied to high throughput screening in drug discovery. The key feature of this technique is the fabrication of a planar patch-clamp substrate using appropriate materials. In this study, a planar patch-clamp substrate was designed and fabricated using a silicon-on-insulator （SOI） wafer. The access resistance and capacitance of SOl-based planar patch-clamp substrates are smaller than those of bulk silicon-based planar substrates, which will reduce the distributed RC noise.

Effect of La^(3+) on myocardiac potassium channels revealed by patch-clamp technique

The effect of La3+ on potassium channels in rat ventricular myocytes was investigated using the whole-cell patch-clamp recording mode. The Ca2+-independent voltage- activated outward K+ current was activated by the depolar- izing pulse in enzymatically isolated rat ventricular myocytes. After addition of different concentrations La3+ to the bath solution, the outward K+ current was depressed gradually. The inhibition effect was in a concentration-dependent man- ner. The phenomena of the outward K+ current, being the main repolarizing current suppressed by La3+, suggest that the effect of lanthanides on myocardial function should be exploited further.

MicroRNA-502-3p regulates GABAergic synapse function in hippocampal neurons

Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's disease-related dementia.Our previous study identified the upregulation of microRNA-502-3p(miR-502-3p)and downregulation of GABA type A receptor subunitα-1 in Alzheimer's disease synapses.This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function.In vitro studies were perfo rmed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs.In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunitα-1 mRNA.Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunitα-1 gene and suppresses the luciferase activity.Furthermore,quantitative reve rse transcription-polymerase chain reaction,miRNA in situ hybridization,immunoblotting,and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunitα-1 level,while suppression of miR-502-3p increased the level of GABA type A receptor subunitα-1 protein.Notably,as a result of the overexpression of miR-502-3p,cell viability was found to be reduced,and the population of necrotic cells was found to be increased.The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney(HEK)recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function,suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function.Additionally,the levels of proteins associated with Alzheimer s disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression.The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p.We propose that micro-RNA,in particular miR-502-3p,could be a potential therapeutic to rget to modulate GABAergic synapse function in neurological disorders,including Alzheimer's disease and Alzheimer's diseaserelated dementia.

马钱子碱抑制豚鼠心室肌细胞钠电流的作用研究

目的本研究旨在分析马钱子碱(brucine)对分离的单个豚鼠心室肌细胞钠电流(INa+)的作用,并探索其抗心律失常的可能机制。方法共选取24只健康的成年豚鼠作为实验对象,雌雄不拘,随机分为4组,每组6只:第1组是未接受任何处理的对照组,之后通过微量加样器使培养皿中brucine药物的终浓度分别达到3μmol/L、10μmol/L、30μmol/L。采用急性酶解法分离获得单个豚鼠心室肌细胞,通过全细胞膜片钳技术测量离子通道电流,以检测不同浓度的brucine对豚鼠心室肌细胞INa+的影响。结果正常的对照组没有明显的INa+电流峰值的变化,而brucine 3μmol/L组给药前后基本不影响INa+电流峰值,当brucine的浓度增加到10μmol/L时,给药前后INa+电流峰值显著下降(P<0.05),在30μmol/L组给药前后INa+电流峰值大幅度减少(P<0.01),并且这种抑制作用呈浓度依赖性。正常对照组及brucine 3μmol/L剂量组中,电流-电压曲线(Ⅰ~Ⅴ曲线)并未受到显著的影响;然而,10μmol/L、30μmol/L剂量组与对照组比较,INa+的Ⅰ~Ⅴ曲线上移,无平行移动,且曲线形状不变。结论Brucine能够通过抑制心室肌细胞钠通道电流发挥抗心律失常作用。

环状RNA mmu_circ_0005019影响小鼠心肌细胞钙激活钾通道电流及动作电位

目的 探索环状RNA mmu_circ_0005019调控小电导钙激活钾(small-conductance calcium-activated potassium, SK)通道蛋白亚基SK3编码基因Kcnn3的表达,以及对小电导钙激活钾通道电流(IK,Ca)和动作电位时程(action potential duration, APD)的影响。方法 在小鼠HL-1细胞中分别构建mmu_circ_0005019过表达和干扰模型,分为过表达组(n=3)、空质粒组(n=3)、干扰1组(n=3)、干扰2组(n=3)、对照组(n=3),通过RT-qPCR、Western blot分析mmu_circ_0005019调节Kcnn3表达的分子机制,应用膜片钳技术电流钳模式记录全细胞的IK,Ca,并用电压钳模式记录APD。结果 成功构建了环状RNA mmu_circ_0005019过表达和干扰的HL-1细胞模型。过表达组的Kcnn3基因表达与空质粒组相比明显上调(P<0.05);干扰1组和干扰2组的Kcnn3基因表达与对照组相比均明显下调(P<0.05)。电生理发现过表达mmu_circ_0005019增加了HL-1细胞IK,Ca电流密度,APD显著缩短;相反,干扰mmu_circ_0005019减少了IK,Ca电流密度,APD显著延长。结论 mmu_circ_0005019可以上调小鼠HL-1细胞Kcnn3的表达水平,从而改变IK,Ca和APD,提示环状RNA mmu_circ_0005019可能在房颤发生中起到促进作用。

无镁诱导仓鼠原代皮质神经元电生理学特性

目的无镁细胞外液建立癫痫放电模型,利用全细胞膜片钳技术,检测仓鼠原代皮质神经元的电生理学特性。方法采用生后1~2 d新生叙利亚仓鼠,分离大脑皮质培养原代神经元培养至第12天,分别予有镁细胞外液(有镁组)和无镁细胞外液(无镁组)孵育3 h,3 h后均更换为正常孵育液继续培养24 h。利用全细胞膜片钳技术,电压钳模式下记录神经元兴奋性突触后电流(excitatory postsynaptic currents,EPSC),电流钳模式下记录神经元兴奋性突触后电位(excitatory postsynaptic potentials,EPSP)。结果与有镁组相比,无镁组仓鼠原代皮质神经元EPSC[(124.38±75.15)Hz vs.(33.93±22.32)Hz,P<0.001]及EPSP[(37.05±38.37)Hz vs.(5.63±9.52)Hz,P<0.01]的频率升高,且差异有统计学意义;而两组之间EPSC及EPSP的振幅、曲线下面积和半宽度的差异无统计学意义(P>0.05)。结论无镁处理后仓鼠原代皮质神经元兴奋性升高,仓鼠原代皮质神经元可用于构建癫痫细胞模型。

基于PiggyBac转座子优化稳定表达细胞系的新型瞬时受体电位M2通道抑制剂筛选

目的:使用PiggyBac(PB)转座系统建立稳定表达瞬时受体电位M2(TRPM2)通道的人胚胎肾细胞HEK293T,并进行TRPM2通道抑制剂筛选,为治疗脑缺血等疾病寻找潜在的药物。方法:根据PB转座原理,构建pPB-hTRPM2真核表达载体。将重组质粒和辅助质粒共同转染至HEK293T细胞中,利用系统携带的荧光与膜片钳鉴定TRPM2基因表达,通过Z'因子评估细胞模型是否适用于钙成像法的高通量筛选。利用钙成像法和膜片钳对11个先导化合物分子进行初步活性评价,测定化合物分子对TRPM2通道的抑制活性。利用氧糖剥夺/再灌注(OGD/R)损伤模型和细胞计数试剂盒8(CCK-8)方法验证筛选得到的化合物分子对损伤细胞的保护作用。利用流式细胞术检测细胞活性氧水平。利用小鼠短暂性大脑中动脉栓塞(tMCAO)模型评价化合物的神经保护作用。结果:成功构建pPB-hTRPM2真核表达载体,构建出可高效表达TRPM2基因的HEK293T细胞系,并同时表达增强型绿色荧光蛋白(EGFP)。在筛选获得的嘌呤霉素抗性细胞中,所有细胞荧光明亮可见,诱导后细胞表现出经典的TRPM2通道电流特征,TRPM2通道电流值与瞬时转染对照组差异无统计学意义(P>0.05)。该筛选系统进行钙成像实验的Z'因子为0.5416,表明其适用于高通量筛选。通过钙成像法结合膜片钳筛选出化合物6,其具有显著的TRPM2通道抑制作用,且1.0μmol/L的化合物6能够显著提高OGD/R后SH-SY5Y细胞的存活率(P<0.05),降低活性氧水平(P<0.05),0.3、1.0 mg/kg的化合物6能降低tMCAO小鼠脑梗死体积百分比(均P<0.05)。结论:利用PiggyBac基因编辑技术成功构建了TRPM2基因稳定表达细胞系,利用钙成像法和膜片钳在候选化合物中成功筛选出一个高亲和力的新的TRPM2通道抑制剂。该抑制剂可以通过降低细胞活性氧水平缓解OGD/R后细胞损伤,并对小鼠脑缺血再灌注损伤具有保护作用。

神经示踪染料DiI影响溃疡性结肠炎小鼠背根神经节神经元电学特性

目的:探究在神经示踪结合膜片钳全细胞记录的实验中,示踪染料DiI是否会对小鼠背根神经节(dorsal root ganglion,DRG)神经元兴奋性产生影响。方法:采用SPF级雄性C57BL/6J小鼠,经5%葡聚糖硫酸钠(dextran sulfate sodium,DSS)诱导溃疡性结肠炎(ulcerative colitis,UC)模型,在T12~L2皮节多点注射DiI逆向示踪躯体感觉神经元,分离全组织DRG并进行全细胞膜片钳记录。结果:HE染色结果显示模型诱导成功。膜片钳记录未经标记的小鼠DRG神经元,模型组小鼠膜电位兴奋性高于正常组小鼠。两组小鼠示踪后,正常示踪组和模型示踪组DiI+神经元兴奋性均低于本组DiI-神经元;与两未示踪组的神经元相比较,两示踪组的DiI-神经元兴奋性分别升高。结论:本实验结果明确了示踪剂DiI会降低DRG神经元的兴奋性,提示相关实验设计中应注意示踪剂的应用对神经元兴奋性的影响,以保证实验结果的可靠性。

紫云英苷对SD大鼠心肌细胞瞬时外向钾通道电流的影响

为探究紫云英苷(astragalin,AG)对心肌细胞瞬时外向钾通道电流Ito的作用,用langendorff主动脉逆向灌流法急性分离出单个SD大鼠心肌细胞,进行全细胞膜片钳试验,记录给药前后Ito的变化及激活、失活和复活过程中的动力学特征。结果表明:不同浓度的AG均表现出对Ito的抑制作用,在50、100、200μmol·L^(-1)浓度范围内,随着药物浓度的增加,抑制作用逐渐增强。以给药前Ito幅值为参照,给予各浓度AG后,电流分别降至原来的(84.06±2.75)%、(66.09±4.65)%、(48.79±5.96)%,后2个浓度的效应与给药前相比具有统计学意义。在动力学特征方面,50、100、200μmol·L^(-1)浓度的AG使瞬时外向钾通道激活阈值上升,失活加速,从失活状态到活化状态的转换延长。综上,AG对SD大鼠心肌细胞上的Ito有抑制作用,此效应的产生与通道的激活、失活和失活后恢复动力学过程改变有关。

超极化激活的环核苷酸门控通道1参与七氟烷诱导的顺行性遗忘作用的机制研究

目的旨在探讨超极化激活的环核苷酸门控通道1(hyperpolarization-activated cyclic nucleotide-gated cation channel 1,HCN1)在七氟烷诱导的顺行性遗忘中的作用机制。方法采用雄性SPF级C57BL/6J野生型小鼠(WT组,n=60)和HCN1基因全身敲除(HCN1-/-)小鼠(HCN1-/-组,n=60)。将两组小鼠分别暴露于不同浓度的七氟烷(0%、0.1%、0.2%、0.4%、0.6%和0.8%)下,每个浓度10只小鼠。随后进行条件性恐惧实验,计算两组小鼠七氟烷抑制条件性恐惧记忆的半数效应浓度(median effective concentration,用EC50表示)。采用全细胞膜片钳技术记录0.125mmol/L七氟烷浓度灌流液对转染HCN1的人胚肾293细胞(HEK293-HCN1)上HCN1电流的影响,比较七氟烷处理前(Control组)和处理后(Sevoflurane组)HCN1电流的变化。结果与-/-WT组小鼠相比,HCN1组小鼠在七氟烷抑制场景恐惧记忆和声音恐惧记忆中的EC50值升高,差异有统计学意义(场景恐惧记忆:0.18%比0.26%,P<0.001;声音恐惧记忆:0.47%比0.49%,P<0.001)。全细胞电生理记录显示,与基础值相比,0.125mmol/L七氟烷抑制HEK293-HCN1细胞在﹣90~﹣140mV范围内的电流幅度(P值均<0.05),并增加了半最大激活电压(V1/2a)值[(﹣108±2.9)mV比(﹣100.1±3.0)mV,(P<0.001)]。结论HCN1电流的抑制可能参与了七氟烷诱导的顺行性遗忘作用。

手动膜片钳检测盐酸罗哌卡因及其右旋异构体对HEK293细胞hERG电流的影响

目的研究比较盐酸罗哌卡因和盐酸罗哌卡因右旋异构体对高表达hERG钾通道的HEK293细胞hERG电流的影响。方法用手动膜片钳检测转染后hERG钾通道稳定表达的HEK293细胞电流,多菲莱德做阳性药,将盐酸罗哌卡因和盐酸罗哌卡因右旋异构体依次稀释成30.00、10.00、3.33、1.11、0.37μmol·L^(-1),依次作用于细胞,记录电流变化,计算抑制率。结果盐酸罗哌卡因0.37、1.11、3.33、10、30μmol·L^(-1)对电流Iherg-tail的抑制率分别为(6.12±0.30)%、(13.04±1.20)%、(19.21±0.33)%、(35.56±0.66)%、(65.37±4.17)%,IC_(50)为19.482μmol·L^(-1)(n=15)。盐酸罗哌卡因右旋异构体0.37、1.11、3.33、10.00、30.00μmol·L^(-1)对电流Iherg-tail的抑制率分别为(4.13±3.43)%、(7.34±5.60)%、(9.49±2.75)%、(16.60±0.87)%、(31.36±1.45)%,IC_(50)>30μmol·L^(-1)(n=15)。阳性对照药品多菲莱德0.00185、0.00556、0.01667、0.05000、0.15000μmol·L^(-1)对电流Iherg-tail的抑制率分别为(7.81±2.77)%、(19.67±1.88)%、(57.16±4.39)%、(89.71±3.55)%、(99.66±0.89)%、IC_(50)为0.015μmol·L^(-1)(n=15)。结论和阳性对照药品多菲莱德比较,盐酸罗哌卡因对hERG通道为弱抑制作用,盐酸罗哌卡因右旋异构体对hERG通道为无明显抑制作用。

冬凌草甲素对海马CA1星形胶质细胞P2X7受体电流的影响

目的:探索冬凌草甲素是否对海马CA1星形胶质细胞P2X7受体电流有影响。方法:采用Autodock软件对冬凌草甲素与P2X7蛋白进行分子对接;采用全细胞膜片钳记录冬凌草甲素对海马CA1星形胶质细胞P2X7受体激动剂Bz-ATP激发电流的影响。结果:冬凌草甲素与P2X7蛋白的结合能为-5.86 kcal/mol,可与P2X7蛋白的Lys592残基形成氢键,与Tyr550残基形成疏水作用;Bz-ATP能激发海马CA1区星形胶质细胞的电流反应,且1000μmol/L Bz-ATP激发的电流反应较强;10μmol/L冬凌草甲素溶液孵育1 h后,海马CA1区星形胶质细胞对谷氨酸能受体激动剂NMDA和AMPA溶液的电流反应无明显变化;对Bz-ATP的电流反应降低,差异具有统计学意义(P<0.05)。结论:冬凌草甲素可与P2X7蛋白对接形成稳定的复合物,具有较好的亲和力;冬凌草甲素可抑制海马CA1星形胶质细胞P2X7受体电流。

抗肿瘤药物开发中体外心脏的安全性风险评估

背景:酪氨酸激酶抑制剂以及其他种类的小分子癌类药物会导致严重的心脏毒性。目的:通过观察抗肿瘤药物在兔体外心脏心电图、心肌动作电位及相关离子通道和心肌细胞毒性的作用,对心脏安全再评价。方法:将兔进行体外心脏灌流,采用舒尼替尼(Sunitinib,0.3,3,10μmol/L),克唑替尼(Crizotinib,0.3,1,3μmol/L),多柔比星(Doxorubicin,1,30μmol/L)顺序灌流120 min,并设空白对照组进行对比,记录心电图和左心室内压。采用手动膜片钳检测3种药物对人源诱导多能干细胞分化的心肌细胞(hiPSC-CMs)动作电位及相关离子通道hERG,Nav1.5和Cav1.2通道电流的影响,采用CellTiter-Glo荧光细胞活力法检测hiPSC-CMs中ATP的水平。结果与结论:①体外心脏灌流实验结果显示:与空白对照组相比,Sunitinib和Crizotinib在≥3μmol/L浓度灌流下可减慢兔心率(P<0.01),延长QT/QTc间期(P<0.01),左心室内压有不同程度的降低。②手动膜片钳实验显示,与空白对照组相比,Sunitinib和Crizotinib在3μmol/L浓度灌流时可明显延长hiPSC-CMs动作电位时程(P<0.01),抑制hERG,Nav1.5和Cav1.2离子通道电流;并结合供试品分析,标识浓度与回收液测定浓度有不同程度的差异。③细胞活力检测结果显示,与空白对照组相比,Sunitinib(IC_(50)=4.64μmol/L),Doxorubicin(IC_(50)=4.21μmol/L)和Crizotinib(IC_(50)=2.87μmol/L)处理后hiPSC-CMs细胞内ATP水平明显降低,即细胞活力显著降低(P<0.01)。④上述结果证实,实验成功建立了抗肿瘤药物的早期心脏安全性评价方法,为后续抗肿瘤药物的开发提供良好的支持和帮助。

犬冬眠心肌跨室壁三层细胞的电生理记录

目的记录跨室壁三层细胞离子流在正常和冬眠心肌中的差异表达,进一步探索其与心源性猝死的关系。方法采用同期全细胞膜片钳技术测定酶解分离的犬冬眠心肌外、中、内层细胞膜离子流慢激活延迟整流钾电流(简称IKs)、动作电位时程(简称APD),由此计算其跨室壁复极离散(TDR)。结果与正常心肌组(以下简称B组)相比,犬冬眠心肌组(简称A组)跨室壁三层细胞的IKs减小,APD延长,且以中层心肌细胞为著;与B组相比,A组TDR明显增加。结论心肌冬眠时,三层心肌细胞的IKs明显减小,APD延长,且心肌细胞的这种变化呈现不均一性,进一步增加了TDR,为恶性心律失常的发生提供了电生理基础,可能使冬眠心肌成为心源性猝死的一个独立危险因素。