小鼠心室肌细胞分离方法的改良及钾电流的记录

目的报道一种改良的小鼠心室肌细胞分离方法,并观察小鼠心室肌细胞动作电位以及钾电流的电生理特性。方法采用双酶消化法分离单个心室肌细胞,应用全细胞膜片钳技术记录动作电位和钾电流。先记录外向钾电流(Ipeak),用低浓度4-氨基吡啶(100μmol/L)使延迟整流钾电流(IKur)失活后记录瞬时外向钾电流(Ito),用Ipeak减去Ito即可得到IKur,在完全失活IKur及Ito后可记录到稳态钾电流(Iss)。结果本法分离所得心室肌细胞横纹清晰,具有正常电生理活性,细胞池中加入层粘连蛋白后有助于细胞贴壁,从而易于形成高阻封接,并记录出小鼠心室肌细胞特征性的动作电位和钾电流。结论本实验所采用的分离方法简便,获得的小鼠心室肌细胞易于封接,且具有正常的电生理活性。     

成年大鼠心室肌细胞的急性分离方法

目的介绍一种新型的成年大鼠心肌细胞的急性分离方法。方法麻醉大鼠后快速取心脏,为心脏先循环灌流无钙台氏液,后循环灌流酶液,酶解完成后取左心室,迅速置于含0.5 mg/ml BSA的KB液(恒温37℃)中拉碎,吹打数次后离心,去上清,温育在含0.5 mg/ml BSA的KB溶液中35 min,梯度复钙。结果首次分离细胞存活率在80%~90%,复钙完成仍有40%~50%的细胞维持杆状,横纹清晰且90%以上细胞处于静止状态。结论通过该方法可获得稳定、高比例的存活心肌细胞,能够为成年大鼠心肌细胞原代培养及电生理学研究提供高品质细胞。     

成年糖尿病大鼠心室肌细胞的分离

目的 探索成年糖尿病大鼠心室肌细胞成功分离的方法。方法 取体质量150～200 g的Sprague-Dawley大鼠20只,单次腹腔注射链脲佐菌素(STZ)建立DM大鼠模型,3周后取大鼠心脏行主动脉逆行灌流分离心室肌细胞;并在倒置显微镜下观察分离的单个心室肌细胞状态。结果 建模成功率达90%,糖尿病大鼠的血糖水平稳定维持在20 mmol/L以上;分离的单个心室肌细胞存活率达70%～90%,且纹理清晰状态好。结论 该糖尿病心室肌细胞的分离方法简单有效。     

Wistar大鼠乳鼠与成年鼠心室肌细胞的分离与性质鉴定

目的 探索和优化稳定的适于电生理实验研究的乳鼠及成年大鼠心室肌细胞分离方法。方法 切碎乳鼠心室肌,胰蛋白酶消化,差速贴壁2 h纯化心室肌细胞,台盼蓝染色判定心肌细胞活力,体外培养48 h后分别行倒置显微镜观察细胞形态,免疫组化鉴定,微电极阵列记录细胞搏动频率和场电位。采用Langendorff灌流成年大鼠心脏,主动脉逆行插管,胶原酶域反复灌流消化约30 min,无钙台氏液冲洗心脏5 min,剪下心室肌组织,台氏液中室温下剪碎,吹打,孵育5 min后,用200目筛网过滤,将细胞悬液用逐步复钙法复钙后,室温静置1 h,用于膜片钳记录。结果 经4 -6次消化后,乳鼠心室组织消化完全,细胞存活率大于80%。倒置显微镜下观察,细胞呈梭形、多角形。 12 h有少部分细胞搏动,48 h细胞交织成网,搏动呈同步性,搏动频率30 - 80次/分。 琢鄄辅肌动蛋白（琢鄄actin）经免疫组化检测,纯度达96%。 Langendorff灌流酶解法可获得形态呈杆状、横纹清晰、膜周边光滑完整、立体感强的单个成年鼠心肌细胞,存活率85%,复钙后存活率50%,可用于膜片钳记录。结论 采用本方法可以获得高产量与高质量的用于电生理检测的心室肌细胞。     

犬三层心室肌细胞的分离和鉴别

目的探讨有效分离和鉴别犬三层心室肌细胞的方法。方法用带有左室前降支的犬心肌组织块灌流分离心室肌细胞,得到的心肌细胞先根据解剖部位大致分成三层,再采用膜片钳技术,在电流钳模式下,随机选择各层15个细胞记录动作电位(AP),根据AP的形态、时程、频率依赖性进一步判断是否为相应层的心室肌细胞。结果经左室前降支插管灌流心肌组织块,可以得到数量多、状态好的心肌细胞。在15个心室肌细胞中,能准确判断其层次的有:外层7个、中层5个、内层8个。结论经冠状动脉插管灌流分离犬心室肌细胞是可行的,结合解剖部位和动作电位特点,能有效鉴别不同层的心室肌细胞。     

心室肌细胞电生理异质性及其临床意义

近年来随着心室肌中层一组具有独特电生理特性的细胞亚群的发现,人们提出了心室肌细胞电生理异质性(electrophysidogicalheterogeneit)这一概念,即不同部位心室肌细胞动作电位的形态、时程各异,对各种病理生理因素和药物的反应性存在着差异[1～3]。这种跨室壁心肌细胞电生理异质性在心电图T波、U波、后除极及其介导的触发活动和折返性心律失常尤其是尖端扭转性心动过速(Tdp)的形成中均具有重要作用。本文拟就这方面的研究进展作一综述。1　不同部位心室肌细胞的电生理特性　　1991年Sicouri等[1]在用玻璃微电极定量研究离体犬左室透壁心肌…     

正常耐钙Spraque-Dawley大鼠心室肌细胞分离方法及体会

目的探讨稳定分离用于膜片钳实验的耐钙Spraque-Dawley大鼠心室肌细胞的方法。方法在自制心脏灌流装置上,采用三步法行逆行主动脉灌流获得单个耐钙心肌细胞,以膜片钳全细胞方式记录离子流。结果在分离过程中如整个心脏保持红润,则细胞数量在90%以上,耐钙细胞KB液中孵育后在70%左右;在分离过程中心脏局部保持红润部位的细胞数量在80%以上,耐钙细胞在60%左右,而苍白区细胞数量变异较大,但一般均在50%以下,且耐钙细胞较少;在分离过程中如整个心脏始终苍白,则细胞数量不仅低于30%,且几乎没有耐钙细胞。结论在心肌细胞分离过程中如严格按照本文的介绍,能获得大量具有正常电生理特性的耐钙心肌细胞。     

卡维地洛对豚鼠心室肌细胞离子流的研究

卡维地洛是临床上广为应用的非选择性 β受体、选择性α1受体阻滞剂 ,在动物实验和临床研究中都显示具有抗心律失常作用 ,本研究系统地观察卡维地洛对豚鼠心室肌细胞离子流的直接影响 ,探讨其细胞电生理作用。1 材料与方法 :选用 2 0 0～ 3 0 0g的健康豚鼠 ,酶解法分离获得单个左心室肌细胞 ,采用膜片钳全细胞记录技术 ,膜片钳放大器为美国AxonInstruments公司产Axopatch 2 0 0B型 ,电压钳制脉冲发放和数据采集由Pclamp 6 0 4软件控制 ,根据所记录离子流的不同采用相应的电极外液和电极内液。卡维地洛 (山东齐鲁制药厂提供 )以浓度递增方…     

ClC-3基因敲除对小鼠心室肌细胞容积敏感性Cl- 电流的影响

目的 :研究小鼠心室肌细胞容积敏感性 Cl-电流与 Cl C-3氯通道的相关性。方法 :采用基因敲除技术获得 Cl C-3基因缺失型小鼠 ;膜片钳全细胞记录法记录分离的小鼠心室肌细胞低渗诱导的容积敏感性 Cl- 电流。结果 :Cl C-3基因敲除小鼠心室肌细胞存在典型的容积敏感性 Cl-电流 ,电生理学特性表现为外向整流性、高电位刺激下的时间依赖性失活 ,以及受到 Cl- 通道阻断剂 (DIDS)的抑制。而且 ,基因敲除鼠的电流幅度与野生鼠和杂交鼠相比无明显差异 (P>0 .0 5)。结论 :Cl C-3不是编码小鼠心室肌细胞容积敏感性氯通道的基因     

M细胞—电生理性质独特的心室肌细胞

本文介绍心室肌Ｍ细胞的独特电生理特性及共在室性心律失常发生和心电图复极波形成中的作用。     

成年小鼠肝组织中长期体外培养的探讨

目的探讨成年肝组织(AHT)体外中长期培养的各项活性指标,寻求以AHT替代成年肝细胞(AHC)培养的方法。方法以0.5mm3大小的肝组织贴壁于盖破片上,静置培养48h后改为旋转培养,每2天作半量换液1次,并取盖玻片作HE染色观察肝组织内细胞存活状况,第26天时结束培养观察;取培养第6天的肝组织设对照组、大黄素实验组、胆红素代谢组,分别行大黄素抗内毒素实验和胆红素代谢实验。结果在对照组,AHT染色鲜明、细胞存活良好;大黄素实验组呈现大黄素的抗内毒素作用而明显提高AHT的细胞活性;胆红素代谢实验组的总胆红素、直接胆红素、间接胆红素分别下降13.69%、19.85%、10.38%。结论AHT保持了体内三维立体结构,体外培养存活期可达26天,生物代谢活性良好,并有省时、操作简便、低成本的优点。     

Differential hypertrophic effects of cardiotrophin-1 on adult cardiomyocytes from normotensive and spontaneously hypertensive rats

Cardiotrophin-1 (CT-1) produces longitudinal elongation of neonatal cardiomyocytes, but its effects in adult cardiomyocytes are not known. Recent observations indicate that CT-1 may be involved in pressure overload left ventricular hypertrophy (LVH). We investigated whether the hypertrophic effects of CT-1 are different in cardiomyocytes isolated from adult normotensive and spontaneously hypertensive rats (SHR). Hypertrophy was evaluated by planimetry and confocal microscopy, contractile proteins were quantified by Western blotting and real-time RT-PCR, and intracellular pathways were analyzed with specific chemical inhibitors. CT-1 increased c-fos and ANP expression (p<0.01) and cell area (p<0.01) in cardiomyocytes from both rat strains. In Wistar cells, CT-1 augmented cell length (p<0.01) but did not modify either the transverse diameter or cell depth. In SHR cells, CT-1 increased cell length (p<0.05), cell width (p<0.01) and cell depth, augmented the expression of myosin light chain-2v (MLC-2v) and skeletal alpha-actin (p<0.01) and enhanced MLC-2v phosphorylation (p<0.01). The blockade of gp130 or LIFR abolished CT-1-induced growth in the two cell types. All distinct effects observed in cardiomyocytes from SHR were mediated by STAT3. Baseline angiotensinogen expression was higher in SHR cells, and CT-1 induced a 1.7-fold and 3.2-fold increase of angiotensinogen mRNA in cardiomyocytes from Wistar rats and SHR respectively. In addition, AT1 blockade inhibited the specific effects of CT-1 in SHR cells. Finally, ex vivo determinations revealed that adult SHR exhibited enhanced myocardial CT-1 (mRNA and protein, p<0.01), increased cell width (p<0.01) and concentric LVH compared with pre-hypertensive SHR. These findings reveal a specific cell-broadening effect of CT-1 in cardiomyocytes from adult SHR and suggest that the hypertensive phenotype of these cells may influence the hypertrophic effects of CT-1, probably by means of an exaggerated induction of angiotensinogen expression. We suggest that CT-1 might facilitate LVH in genetic hypertension through a cross-talk with the renin-angiotensin system.     

成人胰岛分离纯化的初步研究

目的初步研究成人胰岛的分离、纯化方法,为同种异体胰岛移植治疗1型糖尿病进行前期准备。方法采用改良的Ricordi技术消化成人尸体胰腺,然后用连续性密度梯度离心法纯化胰岛。胰岛收获量以国际标准的胰岛当量（islet equivalent,IEQ）表示。结果完成10例成人胰岛分离和纯化,其中5例完成了胰岛当量的统计,胰岛收获量为6367～108725IEQ/胰腺,平均为47678.8IEQ/胰腺,平均每克组织收获2055IEQ。结论采用改进的人胰岛分离方法,可以获得较大产量的有活性的胰岛。     

A method of isolation and culture of microvascular endothelial cells from mouse skin

OBJECTIVES: The study of isolated microvascular endothelial cells from mice has long been impeded due to the many difficulties encountered in isolating and culturing these cells. We focused on developing a method to isolate microvascular endothelial cells from the skin fragments of newborn mice. We also aimed at establishing optimal culture conditions to sustain the growth of these cells. METHODS AND RESULTS: Isolation of murine dermal microvascular endothelial cells (mDMEC) from P3 newborn mice was based first on enzymatic separation of the skin epidermal layer from the dermis using dispase and then on disaggregating dermal cellular elements using collagenase. The cells obtained from the dermis were subjected to a continuous density gradient centrifugation. Cells situated between densities 1.033 and 1.047 were then cultured on collagen IV-coated culture flasks using optimized growth culture conditions. Cells were characterized by endothelial appearance and by the presence and genetic expression of endothelial markers like CD31, NOS3, VEGFR-2 and Tie-2. Uptake of acetylated low-density lipoprotein (Ac-LDL) was used as a functional assay. CONCLUSIONS: The methodology described herein for isolation and culture of murine microvascular endothelium offers a distinctive advantage for those using mouse models to study endothelial cell biology.     

Staurosporine诱导小鼠心肌细胞凋亡模型的构建

目的 :Staurosporine可诱导不同细胞类型的细胞凋亡 ,但尚缺乏其对小鼠心肌细胞作用影响的报道。本研究旨在观察 Staurosporine是否也可引起小鼠心肌细胞的凋亡 ,并对其模型进行分子水平的鉴定。方法 :用 Stau-rosporine处理原代培养的小鼠心肌细胞的直接刺激后 ,观察心肌细胞的形态学变化、DNA片段、半胱天冬蛋白酶(caspase) -3活性、细胞存活率以及细胞膜完整性。结果 :1Staurosporine处理过的心肌细胞具有明显的凋亡形态学特征 :细胞的皱缩、核的浓缩及 DNA梯改变。2 Staurosporine4μmol/ L 对心肌细胞作用 8h后 ,与正常对照组比较细胞存活率降至 3 1.2 % (与对照组比 ,P<0 .0 1) ,且细胞存活率与 Staurosporine的作用浓度和作用时间呈依赖关系 ;同时测定细胞培养液中能反映细胞膜完整性的胞浆内容物乳酸脱氢酶 (L DH)水平 ,发现在 Staurosporine作用 1～ 8h的各个时间点 ,L DH的漏出水平最高未超过 10 % (与对照组相比 ,P>0 .0 5) ;这种高的细胞死亡率与低的细胞膜的损伤率 ,恰恰反映了细胞死亡的性质是凋亡性死亡。3 Staurosporine能激活心肌细胞内的 Caspese-3的活性 ,当使用广谱的 Caspese抑制剂 ZVAD-fmk预处理培养的小鼠心肌细胞后 ,能够有效的阻止上述细胞凋亡的发生 ,从而避免了 Staurospor     

Direct intracellular nitric oxide detection in isolated adult cardiomyocytes: flow cytometric analysis using the fluorescent probe, diaminofluorescein

We assessed the possibility to detect intracellular nitric oxide (NO) with the NO-specific probe 4,5-diaminofluorescein-2/diacetate (DAF-2/DA), by flow cytometry, in fresh adult rat cardiomyocytes, and compared the findings with results obtained from quantitation of cellular nitrate/nitrite (NO(x)) levels. METHODS: Cardiomyocytes were isolated by collagenase perfusion, followed by incubation in a Krebs-Henseleit/2% bovine serum albumin buffer in the presence of 10 microM DAF-2/DA (approximately 0.5 x 10(6) cells/ml). Experimental conditions were: (i) baseline control, (ii) NO donor (2-(N,N-diethylamino)-diazenolate 2-oxide, DEA/NO) administration, and (iii) 120 min simulated ischemia (hypoxia). In addition, control and hypoxic groups were incubated with the NO synthase (NOS) inhibitor, N(W)-nitro-L-arginine methyl ester (L-NAME). Following incubation and washing, intracellular fluorescence of DAF-triazol (DAF-2T, oxidized form of DAF-2/DA) was analyzed by flow cytometry. NO(x) levels were determined with an NO(x) assay. Fluorescence-activated cell sorter (FACS) data were expressed as mean fluorescence intensity (percentage of control) and NO(x) levels as pmol/10(6) cells. RESULTS: Optimal baseline fluorescence was obtained when myocytes were incubated with DAF-2/DA for 3 h at 37 degrees C. The NO donor DEA/NO (500 microM) and hypoxia significantly increased DAF fluorescence and NO(x) levels. L-NAME addition significantly reversed these trends in the hypoxia groups. CONCLUSIONS: We have demonstrated that intracellular NO can be detected in fresh isolated adult cardiomyocytes by flow cytometry with 10 microM DAF-2/DA. Furthermore, we demonstrated that hypoxia is an activator of adult cardiomyocyte NOS, as demonstrated by both end-points. Reproducibility observed between results obtained by FACS analysis and NO(x) assays suggests that DAF-2/DA fluorescence can be regarded as an independent marker for intracellular NO in cardiomyocytes.