这项工作是由美国心脏协会14FTF20370058（DMA）和美国国立卫生研究院T32 HL007101-35（DMA）的支持。

1.电导导管准备和压力校准<ol><li>电导导管连接至血流动力学导管模块。电子校准压力和体积测量通过记录预设的压力和体积的导管模块上设置。记录0毫米汞柱和25毫米汞柱（图1A）一个跟踪和分配的电压到两个压力描记（图1B 和1C）。同样地，记录5 RVU和25 RVU（图1D）的体积跟踪和分配的电压到两个体积描记（1E和1F）。 </li><li>确认与手动压力校准电子压力校准，使用水银柱式血压计。装上血压计袖带端口与3路阀。填3端口止血阀系统，通常用于冠状血管成形术，在使用侧端口RT水。 <ol><li>放置一个电导导管的尖端放入充满流体的止血阀，轻轻地固定机智豪特扭结导管。止血阀连接到血压计和膨胀到200毫米汞柱，并锁定3路阀。检查是否所测量的压力对应于充气的血压计的压力。 </li></ol></li><li>在盐水代替导管加热到37℃，即在操作场和测量压力的水平。调整压力控制，直到录制的压力是零。 </li></ol> 2.麻醉/插管<ol><li>施用氯胺酮/甲苯噻嗪（80〜100/10毫克千克-1），为腹膜内注射。 注意:替代麻醉剂都可以使用。在以前的这种技术11,12的评语是提供麻醉剂的详细列表。适当的麻醉可以通过温和的尾巴捏确认。 </li><li>一旦麻醉，剃颈部和胸部剪及地方上的加热垫。保持鼠标肛温在36.5-37.5ºC。低体温会导致抑郁症心脏率。适用软膏的眼睛，以防止干燥</li><li>做一个中线切口在颈部和解剖气管肌肉掉，露出气管。放置气管内管通过口，同时可视化气管以确保插管，并连接到呼吸器。 </li><li>在手术过程中保持鼠标呼吸机上。根据动物体重设置呼吸机参数设置如前面所述11。潮气量（毫升）= 6.2×（动物体重以公斤为单位），1.01和呼吸率= 53.5×（动物体重以公斤为单位）-0.26。 </li></ol> 3.放置电导导管的LV室<ol><li>颈动脉的方法<ol><li>以确保无菌性，两套无菌手术器械的使用 - 是一个用于初始皮肤切口，一个在开胸进行操作。仪器应使用动物的干燥灭菌个人外科会话期间进行消毒次高压灭菌在每个外科一天结束。 </li><li>后皮肤已经被净化了洗必泰+酒精擦洗皮肤（0.5％洗必泰/ 70％的酒精溶液）的三个周期，做一个切口在右颈从下颌到胸骨。解剖周围组织以暴露右颈，并切断它运行邻近于颈动脉的迷走神经。 </li><li>周围放置的远端的颈动脉（远离胸部）中的无菌6-0丝线缝合，领带和安全的。放置在颈动脉近端下方两个附加​​缝合线（接近胸部）到第一缝合，松散捆扎中间缝合。轻轻拉动近端缝合，并通过将其夹紧在皮肤上固定。确保颈动脉已在继续之前被夹住两个近端和远端。 </li><li>作一小切口在R.颈动脉，接近第一缝合，并纵向朝胸部延伸。 </li><li>将电导导管尖端，先前在温盐水浸泡30分钟，进容器通过切口并使用中间缝合固定导管。 </li><li>轻轻推进导管中通过颈动脉左心室，一边看压力 - 容积环追踪，以确保正确放置。 注意:在导管应产生显示矩形压力-体积环的最优放置（ 见图 2）。如果导管的通过任何遇到阻力，轻轻地拉了回来，并用温和的压力再次前进。导管轻柔旋转可以帮助置入左心室。迫使电导导管可导致严重的心血管并发症或损坏导管。 </li><li>记录基线压力-体积环的导管放置后〜10分钟，获得一个稳定的状态（ 图2）。 </li></ol></li><li>心尖​​方法<ol><li>在麻醉和通风的鼠标，做一个切口FR嗡剑突，并通过胸壁横向直至隔膜是可见的切割。 </li><li>切，虽然隔膜和可视化的心脏顶点。 </li><li>将电导导管进入左心室的穿过针刺伤口（使用25-30g的针）的先端，直到近侧电极只是心室内侧。 </li><li>记录基线压力 - 体积环的导管放置后〜10分钟，达到稳定状态。 </li></ol></li></ol> 4.变后负荷使用瞬态主动脉阻断<ol><li>要进行短暂的主动脉阻塞，做一个小的水平切口，在胸腔上部和解剖周围组织揭露横向主动脉。 </li><li>将横向主动脉下6-0丝线结扎。经过压力容积环已经恢复到基线，扣住缝线的两端用针钳，轻轻地，慢慢抬高缝合过1-2秒，慢慢释放压力。 </LI&gt; <li>重复此过程，直到三个独立的最佳记录被从同一动物制成。 注:最佳录音应至少有5个压力容量循环周期和紧张的缝合（ 图3A和3C）的应用过程中稳步上升，收缩末期压力。 </li></ol> 5.变预紧使用瞬态下腔静脉阻塞（IVC） <ol><li>要进行短暂的下腔静脉阻塞，使下面的剑突水平切口，隔膜暴露下腔静脉下方。 </li><li>放置IVC下6-0丝线结扎。后压力 - 容积环已经回到基线，​​扣用针夹具的缝合线的两端;轻轻地，慢慢抬高缝合过1-2秒，慢慢释放压力。 IVC闭塞，也可以通过压力使用棉花温柔应用程序执行倾斜拭子。 </li><li>重复这个过程，直到三个独立的最佳录音m个从相同的动物ADE。 注意:最佳记录应至少有5个压力体积循环周期和张力对缝线施加期间中左心室舒张末期压力稳定下降（图4A 和4B）。 </li></ol> 6.盐水校准<ol><li>在研究结束时，一个并联电导（Ⅴp）的值可以是获得由通过颈静脉注射高渗盐水（15％）到动物的10微升丸药（图5A 和5B）。 注:此丸会导致体积的压力没有变化的明显增加。这在体积明显的变化是在血池电导，而不是一个改变的结果，由于在卷的实际增加。在DP / dt的最大瞬时下降可以看出，由于高渗盐水有负性肌力作用13。计算出的V P能够沿着进入压力容积环分析软件与试管校准参数和从转换的RVU以微升。 </li></ol> 7.试管校准<ol><li>要执行校准试管，放置具有在加热垫上或水浴提供由制造商已知直径的孔中的试管加热到37ºC。从小鼠进行血流动力学评估填充第4-5孔新鲜温暖的肝素的血液。 注:试管校准允许使用鼠标血左心室的血池准确的评估，并允许从的RVU微升的转换数据量。 </li><li>将电导导管进入第一口井，直到所有的电极被淹没。轻柔地将导管孔，这将产生不同的RVU。 </li><li>记录中的RVU音量通道的电导的变化。选择最高RVU用于校准。 注:各孔的体积既可以由1使用等式为volum计算）Ë圆柱体，其中所述半径是试管井和长度的是基于内部的两个感测电极或2）在制造商的说明检查之间的长度。电导输出可以与已知体积相关，以开发出将数据从进入的RVU微升11将校准方程。 </li></ol> 8.安乐死<ol><li>在协议结束时，将小鼠用颈椎脱臼而麻醉下安乐死。 </li><li>为了确保死亡，已经历颈脱位小鼠必须经过安乐死的辅助方法。我们使用放血麻醉下，与在麻醉下采集心脏组织的用于实验，或双边开胸。 </li></ol> 9.使用数据分析压力容积环分析软件<ol><li>计算V p从盐水校准<ol><li>选择压力和VOLU我回路高渗盐水的喷射期间获得（图5A和5B） </li><li>出口循环到压力体积分析软件。选择选项盐水校准（图5C） </li><li>记录计算出的V P值 （图5D）。 注:购买V P值是通过识别1）舒张末期容积与从盐校准收缩末期容积的交集和2）舒张末期容积=收缩末期容积线计算。这些线的交叉点提供在V p，是由压力容积环的分析软件进行计算。 </li></ol></li><li>输入传导到体积（RVU）的体积通道选项的关系（ 图1F） </li><li>测量基线压力 - 体积循环关系<ol><li>从压力和体积渠道8-10个心动周期，一旦稳定状态已经实现（ 图2A），并出口到分析软件洁具。确定5-6呼气末环（ 图2B） </li><li>使用V P值来校正平行电导。选择"稳态"选项，并产生一个血液动力学汇总表（图2C） </li></ol></li><li>在主动脉缩窄测量压力容量环的关系<ol><li>选择从压力和体积沟道8-10个心动周期对应于之前的舒张末期压力（ 图3A）和出口到分析软件的增加主动脉缩窄。识别5-6呼气末回路（图3C） </li><li>选择"收缩"的分析（ 图3B），这将计算结束收缩的压力容积关系（ESPVR） </li></ol></li><li>在IVC缩窄测量压力容量环的关系<ol><li>从对应于下腔静脉收缩压力和体积渠道8-10个心动周期（FIGURË4A），并出口到分析软件。确定5-6呼气末环（ 图4B） </li><li>选择"收缩"的分析（图3B），这将计算预压Recruitable冲程工作（PRSW）（图4C），最大上升/ dt的VS EDV（图4D），以及ESPVR和最终舒张压容积关系（图4E） </li></ol></li></ol>

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</ol>

作者什么都没有透露。

我们描述了使用小鼠电导导管，以获得两个心脏收缩和舒张的综合分析perfoming压力 - 容积环分析的方法。菅佐川急便和他 ​​的同事利用压力容积循环，以确定心脏收缩的措施，在ESPVR专门的坡度，或收缩末期弹性（E ES）和E 最大 。顺应性，通过压力的比率定义为体积（P / V），上变化收缩的持续时间。在每个心脏收缩，瞬时弹性度是依赖于心脏速率和心肌收缩力，但在很大程度上独立预紧或后负荷3,17的。因此，峰值弹性度或E 最大是用来定义心脏收缩即大多独立的荷载条件从单个心动周期18。一个密切相关的收缩性术语中，E ES是由ESPVR的斜率在稳定CON限定在一系列心动周期DITION。使用E ES出现线性关系负载范围有限，E ES可以是曲线和curvilinearity正在与相关国家收缩19。在电子商务ES或E 最大的增加表明增加的收缩和减少代表减少的收缩。除了​​E- ES或E max时，压力-容积环的数据可以用来推导替代收缩指数如:上升/下降速率，EDV关系20，预紧-recruitable冲程工作（PRSW）21或最大功率的EDV关系22。这些替代参数检查的范围上预加载的心脏反应，并且可以与IVC收缩而获得。值得注意的是，虽然ESPVR相对负载无关，这不是绝对的。有在从主动脉或腔静脉收缩23衍生ESPVRs差异，与具有上收缩的持续时间有更大的影响，缩短的程度主动脉缩窄8。 类似于ESPVR，舒张末期压力 - 容积关系（EDPVR）提供心脏遵守的负载独立量度。这种关系是通过识别舒张末期压力在一定范围的负荷条件下，然后将其装配到要么定义为P =α指数模型导出（例如SS V -1）+ PO（α是一个刚性和缩放系数，β- =室刚度系数和P在0体积0 =压力）8或线性模型（图4C所示）。压力容量环分析，可以提供关于舒张功能的更多信息。主动放松的措施是从室内压等容舒张时的下降得到。从松弛的峰值速率LV充盈的发作单指数衰变被表示为时间常数t 8。 平行电导的测定是加利福尼亚州的评估临界rdiac音量。尽管我们已经描述了使用盐水校准，以评估平行电导，文学越来越多已确定替代的方法来评估并行电导。盐水校准利用班的公式9，其中，α为均匀电场校正因子。然而，移动心脏壁改变电场从而提高动态α常数24的问题。而且，室壁到电导的贡献收缩和舒张过程中变化，然而，盐水校准用来并联电导24的固定值。为了解决这个问题，时间的概念变场校正，称为卫方程，和瞬时平行电导，称为"导纳"，已设计出25。已创建新的微导管衡量导纳和在心肌损伤模型1成功地利用。这些技术代表了显ficant进展的压力 - 容积环分析的评估。 从压力 - 容积环分析得到的收缩和舒张参数提供心脏功能的综合评价。这些分析的准确度和精度依赖于关注实验细节。为了获得高质量的心脏压力容积环的小鼠，一个熟练的操作者是至关重要的。此外，必须注意在选择麻醉，适当的通风，体温，和导管的定位进入左心室。获得的数据的正确分析将依赖于稳定的仪器，盐水和试管校准。这些方面在这些书面方式强调和影随行应提供在其着手对这些心脏生理研究的框架。 故障排除 1.低血压或心动过缓的基础状态:正常老鼠的血压和心脏ř在以前的这个主题11条点评吃了总结。 a）确保体温高于36ºC使用直肠体温计。如果低于36ºC，加热垫或加热灯可以用来提高小鼠的体温。 b）评估为外科手术过程中止血。止血可以采用手动压力或烧灼来实现。显著体积损失可以用生理盐水液推注治疗。 c）评估鼠标是否过度麻醉。如果此被怀疑，盐水流体丸剂可用于治疗低血压。值得注意的是，氯胺酮/赛拉嗪，其用于在演示实验，可以cardiodepressive。可替代地，使用异氟烷（诱导3-4％，维持1.5％混合的含95％氧气和5％的CO 2）吸入麻醉可被取代。替代麻醉剂，如氨基甲酸酯（800毫克千克-1）/依托咪酯（5-10毫克千克-1）/吗啡（2毫克千克-1）或戊巴比妥钠（40-80毫克千克-1）可以腹膜内11给药。 2.噪声中的压力或体积的通道:这可能是由于电磁干扰或一个破碎/脏电导导管。使这可能有助于干扰电子设备进行认真评估。如果噪音仍然存在，检查在显微镜下电导导管，以评估粘性材料或损坏导管尖端。如果可能，尝试新鲜的电导导管，看它是否补救措施的问题。 3.卷记录漂移随时间:这可能是由于一个预热时间为血液动力学模块不足。允许模块预热前的校准步骤和分析30分钟。 5.音量读数大于预期:这可能发生，如果测得的体积并没有得到纠正并行电导。 PERFORM在协议第6步概述获得并联电导盐水校准。 6.质量差压力体积循环:理想的压力-容积环具有正方形或矩形的外观（参见图2为例）。如果环路的形状是不规则的，轻轻操纵或扭曲电导导管在LV腔，看它是否改变了环的形状。我们首选的方法来访问LV是通过颈动脉（协议步骤3.1），因为这不需要开胸，这可能会影响血液动力学。但是，颈动脉的方法可以容易导管工件不规则环路。因此，心尖方法（协议步骤3.2）可以用来解决这一问题。

心脏压力容积环分析提供心脏功能的详细信息，其中的金标准功能评估1。虽然诸如超声心动图或心脏MRI成像技术提供的功能的措施，这些措施在很大程度上取决于负载条件。心脏收缩和舒张的负载独立的措施需要心室压力和体积的关系在一定范围内的前后负荷的动态测量。压力容积关系的这种认识源于佐川急便和同事2,3的开创性工作。他们在体外灌注犬心脏表明，压力容积环衍生收缩措施是独立的负载条件4。 在这些分析的体内应用成为可能的传导导管在20世纪80年代的发展。这使得嘉的技术进步SS和他的同事进行的人类5,6压力-容积环分析。电导导管和改进手术技术在上世纪90年代7小型化由啮齿类动物心脏功能分析是可行的，允许遗传和药理学研究被执行。这一进步此后引发广泛使用的压力容积环分析，并产生了大量的洞察哺乳动物心脏生理。 在使用电导导管，并从中获得的数据的解释的一个关键概念是体积和电导之间的关系。电导是负相关的电压，这是使用与近侧放置电极，通常放在下面的主动脉瓣，和远侧，在LV尖8的导管测量。被改变电压或电导的变化电流从近端到远端电极的测量。虽然血池贡献š显著电导，心室壁的贡献，称为并联电导（V p）的 ，以测得的电导必须减去，以获得绝对的LV体积测量。 所述的方法来执行此校正，称为盐水校准，在下面的协议进行了讨论。电导和体积之间的数学关系，由班和同事描述的是体积= 1 /α; （ρL 2）（GG p），其中 α=均匀的场校正系数，ρ=电阻率血液，L为电极之间的距离，G =电导和 G p值=非血液电导9。值得注意的是，在小鼠的统一场校正系数接近1.0，由于小室容积10。再加上压力传感器，电导导管提供实时同步的压力和体积数据。 心脏PRESSU再卷分析呈现特别优势的心脏功能的其他措施，因为它们允许用于心室功能独立的负载条件和心脏速率的测量。收缩的具体负载无关的心脏指标包括:收缩末期压力容积关系（ESPVR），D P / D T最大末端舒张末期容积关系，最大顺应性（E max）和预加载recruitable工作行程（PRSW）。舒张功能的负载无关的指标是舒张末期压力容积关系（EDPVR）11。以下协议描述心脏的压力容积环分析的行为，同时使用一个颈动脉和顶部的方法。虽然进行这些研究的方法进行了详细先前8,11进行了说明，我们将审查的关键步骤，以获得精确的压力容积测量，包括盐水和试管校准修正，并提供THES的可视化演示Ë程序。研究与开展这项研究的动物按批准的方案和杜克大学医学中心的机构动物护理和使用委员会的动物福利法规进行处理。

<table><tbody><tr><td>AnaSed (xylazine)&amp;nbsp;</td><td>Lloyd Laboratories</td><td>NADA no. 139-236</td><td>Anesthetic</td></tr><tr><td>Ketaset (ketamine)</td><td>Pfizer</td><td>440842</td><td>Anesthetic</td></tr><tr><td>VIP3000</td><td>Matrx Medical Inc.</td><td></td><td>Anesthesia machine</td></tr><tr><td>Ventilator</td><td>Harvard Apparatus</td><td>Model 683</td><td>Surgical Equipment</td></tr><tr><td>Tubing kit</td><td>Harvard Apparatus</td><td>72-1049</td><td>Surgical Equipment</td></tr><tr><td>Homeothermic Blanket&amp;nbsp;</td><td>Kaz Inc.</td><td>5628</td><td>Surgical Equipment</td></tr><tr><td>Stereo microscope</td><td>Carl Zeiss Optical Inc.</td><td>Stemi 2000</td><td>Surgical Equipment</td></tr><tr><td>Illuminator</td><td>Cole&amp;ndash;Parmer</td><td>41720</td><td>Surgical Equipment</td></tr><tr><td>Dumont no. 55 Dumostar Forceps&amp;nbsp;</td><td>Fine Science Tools Inc</td><td>11295-51</td><td>Surgical Instruments</td></tr><tr><td>Graefe forceps, curved&amp;nbsp;</td><td>Fine Science Tools Inc</td><td>11052-10</td><td>Surgical Instruments</td></tr><tr><td>Moria MC31 forceps&amp;nbsp;</td><td>Fine Science Tools Inc</td><td>11370-31</td><td>Surgical Instruments</td></tr><tr><td>Mayo scissors&amp;nbsp;</td><td>Fine Science Tools Inc</td><td>14512-15</td><td>Surgical Instruments</td></tr><tr><td>Iris scissors&amp;nbsp;</td><td>Fine Science Tools Inc</td><td>14041-10</td><td>Surgical Instruments</td></tr><tr><td>Halsey needle holder&amp;nbsp;</td><td>Fine Science Tools Inc</td><td>12501-13</td><td>Surgical Instruments</td></tr><tr><td>Olsen&amp;ndash;Hegar needle holder&amp;nbsp;</td><td>Fine Science Tools Inc</td><td>12002-12</td><td>Surgical Instruments</td></tr><tr><td>spring scissors</td><td>Fine Science Tools Inc</td><td>15610-08</td><td>Surgical Instruments</td></tr><tr><td>disposable underpads</td><td>Kendall/Tyco Healthcare</td><td>1038</td><td>Surgical Supplies</td></tr><tr><td>Sterile gauze sponges, sterile&amp;nbsp;</td><td>Dukal</td><td>62208</td><td>Surgical Supplies</td></tr><tr><td>Cotton-tipped applicators, sterile&amp;nbsp;</td><td>Solon</td><td>368</td><td>Surgical Supplies</td></tr><tr><td>Surgical suture,&amp;nbsp; silk, 6-0&amp;nbsp;</td><td>DemeTECH</td><td>FT-639-1</td><td>Surgical Supplies</td></tr><tr><td>1 cc Insulin syringes&amp;nbsp;</td><td>Becton Dickenson</td><td>329412</td><td>Surgical Supplies</td></tr><tr><td>Access 9 Hemostasis Valve</td><td>Merit Medical&amp;nbsp;</td><td>MAP111</td><td>Hemodynamic equipment</td></tr><tr><td>Sphygmomanometer</td><td>Baumanometer</td><td>320</td><td>Hemodynamic equipment</td></tr><tr><td>Millar PV system MPVS-300/400 or MPVS Ultra (includes calibration cuvette)</td><td>ADInstruments Inc</td><td></td><td>Hemodynamic equipment</td></tr><tr><td>1.4F conductance catheter&amp;nbsp;</td><td>ADInstruments Inc</td><td>SPR-839</td><td>Hemodynamic equipment</td></tr><tr><td>PowerLab 4/30 with Chart Pro</td><td>ADInstruments Inc.</td><td>ML866/P</td><td>Hemodynamic software</td></tr><tr><td>animal clipper</td><td>Wahl</td><td>8787-450A</td><td>Miscellaneous</td></tr><tr><td>Intradermic tubing PE-10</td><td>Becton Dickenson</td><td>427401</td><td>Miscellaneous</td></tr><tr><td>Intradermic tubing PE-50</td><td>Becton Dickenson</td><td>427411</td><td>Miscellaneous</td></tr><tr><td>Needle assortment (18, 25 and 30 gauge; Thomas Scientific)</td><td></td><td></td><td>Miscellaneous</td></tr><tr><td>0.9% (wt/vol) sodium chloride injection, USP)</td><td>Hospira</td><td>NDC no. 0409-4888-50</td><td>Miscellaneous</td></tr><tr><td>Surgical tape</td><td></td><td></td><td>Miscellaneous</td></tr><tr><td>Alconox (Alconox Inc.) for catheter cleaning</td><td>ADInstruments Inc.</td><td></td><td>Miscellaneous</td></tr></tbody></table>

cardiac pressure-volume loop analysis using conductance catheters in mice

Cardiac pressure-volume loop analysis is the &#8220;gold-standard&#8221; in the assessment of load-dependent and load-independent measures of ventricular systolic and diastolic function. Measures of ventricular contractility and compliance are obtained through examination of cardiac response to changes in afterload and preload. These techniques were originally developed nearly three decades ago to measure cardiac function in large mammals and humans. The application of these analyses to small mammals, such as mice, has been accomplished through the optimization of microsurgical techniques and creation of conductance catheters. Conductance catheters allow for estimation of the blood pool by exploiting the relationship between electrical conductance and volume. When properly performed, these techniques allow for testing of cardiac function in genetic mutant mouse models or in drug treatment studies. The accuracy and precision of these studies are dependent on careful attention to the calibration of instruments, systematic conduct of hemodynamic measurements and data analyses. We will review the methods of conducting pressure-volume loop experiments using a conductance catheter in mice.

压力-容积环分析可以用于测量在基因修饰的小鼠14,15或小鼠接受药物研究16心脏功能。代表压力容积环是由以前发表的著作16提供的调查β-arrestin的效果偏向AT1受体配体，TRV120023。为了测试TRV120023是否影响在体内的心脏功能，在接收到传统的和新颖的血管紧张素受体 ​​阻滞剂的野生型小鼠中进行压力-容积环分析。 TRV120023静脉滴注增强心肌收缩显著（图6 和表1，图从Kim等AJP 2012 16修改）。推导出收缩的措施，从主动脉缩窄。 <img alt="图1" src="/files/ftp_upload/52942/52942fig1.jpg" /> 图1.心脏压力和体积校准。<a href="https://www.jove.com/files/ftp_upload/52942/52942fig1highres.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 在压力容积环软件，分配渠道压力和容量的录音。（A）使用的血流动力学导管模块，设置音量设置为5 RVU和25 RVU，选择两卷，（B）打开选项下通道参展音量录音，（C ）选择单位换算，公开"的2点校准"，选择"1点"，并指定为5 RVU，选择"点2"，并指定为25 RVU，（D）设定压力为0毫米汞柱和25毫米汞柱，（E ）信道下表现出压力记录，（F）选择单位换算，公开"的2点校准"，选择"1点"，并指定为0，毫米汞柱，选择"点2"和屁股打开选项IGN 25毫米汞柱。通过选择"OK"接受任务。 <img alt="图2" src="/files/ftp_upload/52942/52942fig2.jpg" /> 图2.基线血流动力学 <a href="https://www.jove.com/files/ftp_upload/52942/52942fig2highres.jpg" target="_blank">，请点击此处查看该图的放大版本。</a> （一）在基础状态下，从代表心动周期的压力和体积渠道截图，（B）选择呼气末基线压力容积已校正并联电导分析循环。（C）从所选的循环计算的基准血流动力学汇总表; PES，结束收缩压; PED，舒张末压; VES，收缩末期容积;韦达，舒张末期容积; SV =每搏输出量<img alt="图3" src="/文件/ ftp_upload / 52942 / 52942fig3.jpg"/&gt; 图3.主动脉缩窄血流动力学 <a href="https://www.jove.com/files/ftp_upload/52942/52942fig3highres.jpg" target="_blank">请点击此处查看该图的放大版本。</a> （A）中从代表心动周期期间主动脉缩窄的压力和体积通道截图，（B）的菜单选择来执行收缩分析，（C）的期间，主动脉缩窄用于分析选定压力-容积环。（D）的 ESPVR从主动脉缩窄环路测。 <img alt="图4" src="/files/ftp_upload/52942/52942fig4.jpg" /> 图4.下腔静脉缩窄血流动力学 <a href="https://www.jove.com/files/ftp_upload/52942/52942fig4highres.jpg" target="_blank">请点击此处查看该图的放大版本。</a> </a&gt; （A）的过程中的IVC缩颈从代表心脏周期的压力和体积通道截图，（B）的过程中IVC缩颈用于分析选定压力-容积环。使用PV环从下腔静脉收缩，预压Recruitable做功（C），最大DP / DT VS EDV（D），以及 ESPVR和EDPVR可以衡量的。 <img alt="图5" src="/files/ftp_upload/52942/52942fig5.jpg" /> 图5.盐水校准 <a href="https://www.jove.com/files/ftp_upload/52942/52942fig5highres.jpg" target="_blank">请点击此处查看该图的放大版本。</a> （一）高渗盐水注射液（B）选择的生理盐水注射压力容积环˚F过程中从代表心动周期的压力和体积渠道截图<html>或分析。需要注意的是压力将保持不变，而量将显著增加，（C）菜单选择执行生理盐水校准，（D），盐水注射和收缩末期容积=舒张末期过程中产生的行措施结束收缩的VS舒张末期容积音量。这些线的交叉点提供了V P上的平行电导。 <img alt="图6" src="/files/ftp_upload/52942/52942fig6.jpg" /> 图6.变化收缩与药品监督管理局 变化在心脏收缩，通过端收缩顺应性测量，在用盐水，氯沙坦为5mg / kg /小时或TRV023为100μg/ kg /小时处理5分钟，野生型小鼠中评估。 TRV023处理的小鼠开发相比，氯沙坦处理的小鼠在端收缩顺应性一个显著增加。 * P &lt;0.05与氯沙坦通过单因素方差分析。 内容】"FO:保持together.within页="总是"&gt; <img alt="表1" src="/files/ftp_upload/52942/52942table1.jpg" /> 表1野生型小鼠;血流动力学的β-arrestin的2偏置AT1受体激动剂响应 最终收缩压（ESP）是TRV120023（TRV）和氯沙坦输液后显著下降。心肌收缩力，E ES和E 最大是在TRV120023显著增加100微克·千克-1·分-1输液组。 （* P &lt;0.01;†P &lt;0.05;‡P &lt;0.001; N = 5-6 /组）。 P值反映了同样的治疗组采用单因素方差分析中的基础条件比较。心脏收缩参数使用主动脉缩窄协议获得。 AT1受体，血管紧张素Ⅱ受体; HR，心脏率; EDP​​，舒张末期压力; ESV，收缩末期容积; EDV，舒张末期容积; ËES，收缩末期弹性; EF，Ejection分数; Ë 最大 ，最大顺应性;上升/ dt最大值并且dp / dt的分钟，在心室，分别压力变化的最大和最小速率; τ，等容舒张期不变。 <a href="https://www.jove.com/files/ftp_upload/52942/52942table1highres.jpg" target="_blank">请点击这里查看此表的放大版本。</a>

Watch this Scientific Journal Video about Cardiac Pressure-Volume Loop Analysis Using Conductance Catheters in Mice at JoVE.com

Cardiac Pressure-Volume Loop Analysis Using Conductance Catheters in Mice

Cardiac pressure-volume loop analysis is the most comprehensive way to measure cardiac function in the intact heart. We describe a technique to perform and analyze cardiac pressure volume loops, using conductance catheters.

心脏压力容量环分析小鼠使用电导导管

Cardiac pressure-volume loop analysis is the &#8220;gold-standard&#8221; in the assessment of load-dependent and load-independent measures of ventricular ...

cardiac-pressure-volume-loop-analysis-using-conductance-catheters

Nanyang Technological University

Research

JoVE Journal

Biology

19.4K 次观看.  Duke University Medical Center. Cardiac pressure-volume loop analysis is the most comprehensive way to measure cardiac function in the intact heart. We describe a technique to perform and analyze cardiac pressure volume loops, using conductance catheters. 

视频: Cardiac Pressure-Volume Loop Analysis Using Conductance Catheters in Mice

Cardiac Catheterization in Mice to Measure the Pressure Volume Relationship: Investigating the Bowditch Effect

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these strategies is to examine their effects on heart function. There are several techniques to measure in vivo cardiac mechanics (e.g., echocardiography, pressure/volume relations, etc.). Compared to echocardiography, real-time left ventricular (LV) pressure/volume analysis via catheterization is more precise and insightful in assessing LV function. Additionally, LV pressure/volume analysis provides the ability to instantaneously record changes during manipulations of contractility (e.g., &#946;-adrenergic stimulation) and pathological insults (e.g., ischemia/reperfusion injury). In addition to the maximum (+dP/dt) and minimum (-dP/dt) rate of pressure change in the LV, an accurate assessment of LV function via several load-independent indexes (e.g., end systolic pressure volume relationship and preload recruitable stroke work) can be attained. Heart rate has a significant effect on LV contractility such that an increase in the heart rate is the primary mechanism to increase cardiac output (i.e., Bowditch effect). Thus, when comparing hemodynamics between experimental groups, it is necessary to have similar heart rates. Furthermore, a hallmark of many cardiomyopathy models is a decrease in contractile reserve (i.e., decreased Bowditch effect). Consequently, vital information can be obtained by determining the effects of increasing heart rate on contractility. Our and others data has demonstrated that the neuronal nitric oxide synthase (NOS1) knockout mouse has decreased contractility. Here we describe the procedure of measuring LV pressure/volume with increasing heart rates using the NOS1 knockout mouse model.

This article describes the measurement of murine left ventricular function via pressure/volume analysis at different heart rates.

心导​​管在小鼠测量压力体积的关系:调查的影响鲍迪奇

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these ...

科研

医学

Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes

The protocol presented here is designed to study the activation of the large conductance, voltage- and Ca2+-activated K+ (BK) channels. The protocol may also be used to study the structure-function relationship for other ion channels and neurotransmitter receptors1. BK channels are widely expressed in different tissues and have been implicated in many physiological functions, including regulation of smooth muscle contraction, frequency tuning of inner hair cells and regulation of neurotransmitter release2-6. BK channels are activated by membrane depolarization and by intracellular Ca2+ and Mg2+ 6-9. Therefore, the protocol is designed to control both the membrane voltage and the intracellular solution. In this protocol, messenger RNA of BK channels is injected into Xenopus laevis oocytes (stage V-VI) followed by 2-5 days of incubation at 18&deg;C10-13. Membrane patches that contain single or multiple BK channels are excised with the inside-out configuration using patch clamp techniques10-13. The intracellular side of the patch is perfused with desired solutions during recording so that the channel activation under different conditions can be examined. To summarize, the mRNA of BK channels is injected into Xenopus laevis oocytes to express channel proteins on the oocyte membrane; patch clamp techniques are used to record currents flowing through the channels under controlled voltage and intracellular solutions.

Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes

Ionic current of BK channels is recorded using patch clamp techniques. BK channels are expressed in Xenopus oocytes by injecting messenger RNA. The intracellular solution during patch clamp recordings is controlled by a perfusion system.

膜片钳和灌注技术研究离子通道的表达爪蟾卵母细胞

The protocol presented here is designed to study the activation of the large conductance, voltage- and Ca2+-activated K+ (BK) channels. The protocol may ...

生物学

Hemodynamic Characterization of Rodent Models of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a rare disease of the pulmonary vasculature characterized by endothelial cell apoptosis, smooth muscle proliferation and obliteration of pulmonary arterioles. This in turn results in right ventricular (RV) failure, with significant morbidity and mortality. Rodent models of PAH, in the mouse and the rat, are important for understanding the pathophysiology underlying this rare disease. Notably, different models of PAH may be associated with different degrees of pulmonary hypertension, RV hypertrophy and RV failure. Therefore, a complete hemodynamic characterization of mice and rats with PAH is critical in determining the effects of drugs or genetic modifications on the disease. 
Here we demonstrate standard procedures for assessment of right ventricular function and hemodynamics in both rat and mouse PAH models. Echocardiography is useful in determining RV function in rats, although obtaining standard views of the right ventricle is challenging in the awake mouse. Access for right heart catheterization is obtained by the internal jugular vein in closed-chest mice and rats. Pressures can be measured using polyethylene tubing with a fluid pressure transducer or a miniature micromanometer pressure catheter. Pressure-volume loop analysis can be performed in the open chest. After obtaining hemodynamics, the rodent is euthanized. The heart can be dissected to separate the RV free wall from the left ventricle (LV) and septum, allowing an assessment of RV hypertrophy using the Fulton index (RV/(LV+S)). Then samples can be harvested from the heart, lungs and other tissues as needed.

Pulmonary arterial hypertension (PAH) is a disease of pulmonary arterioles that leads to their obliteration and the development of right ventricular failure. Rodent models of PAH are critical in understanding the pathophysiology of PAH. Here we demonstrate hemodynamic characterization, with right heart catheterization and echocardiography, in the mouse and rat.

肺动脉高压的啮齿动物模型的血流动力学特性

Pulmonary arterial hypertension (PAH) is a rare disease of the pulmonary vasculature characterized by endothelial cell apoptosis, smooth muscle ...

Bioengineering Human Microvascular Networks in Immunodeficient Mice

The future of tissue engineering and cell-based therapies for tissue regeneration will likely rely on our ability to generate functional vascular networks in vivo. In this regard, the search for experimental models to build blood vessel networks in vivo is of utmost importance 1. The feasibility of bioengineering microvascular networks in vivo was first shown using human tissue-derived mature endothelial cells (ECs) 2-4; however, such autologous endothelial cells present problems for wide clinical use, because they are difficult to obtain in sufficient quantities and require harvesting from existing vasculature. These limitations have instigated the search for other sources of ECs. The identification of endothelial colony-forming cells (ECFCs) in blood presented an opportunity to non-invasively obtain ECs 5-7. We and other authors have shown that adult and cord blood-derived ECFCs have the capacity to form functional vascular networks in vivo 7-11. Importantly, these studies have also shown that to obtain stable and durable vascular networks, ECFCs require co-implantation with perivascular cells. The assay we describe here illustrates this concept: we show how human cord blood-derived ECFCs can be combined with bone marrow-derived mesenchymal stem cells (MSCs) as a single cell suspension in a collagen/fibronectin/fibrinogen gel to form a functional human vascular network within 7 days after implantation into an immunodeficient mouse. The presence of human ECFC-lined lumens containing host erythrocytes can be seen throughout the implants indicating not only the formation (de novo) of a vascular network, but also the development of functional anastomoses with the host circulatory system. This murine model of bioengineered human vascular network is ideally suited for studies on the cellular and molecular mechanisms of human vascular network formation and for the development of strategies to vascularize engineered tissues.

Here, we describe a methodology to deliver human cord blood-derived endothelial colony-forming cells (ECFCs) and bone marrow-derived mesenchymal stem cells (MSCs), embedded in a collagen/fibronectin gel, subcutaneously into immunodeficient mice. This cell/gel combination generates a human vascular network that connects with the mouse vasculature.

生物人类免疫缺陷小鼠的微血管网络

The future of tissue engineering and cell-based therapies for tissue regeneration will likely rely on our ability to generate functional vascular networks ...

Biventricular Assessment of Cardiac Function and Pressure-Volume Loops by Closed-Chest Catheterization in Mice

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) generated by recording both pressure and volume during cardiac catheterization are vital when assessing both systolic and diastolic cardiac function. Left and right heart function are closely related, reflected in ventricular interdependence. Thus, recording biventricular function in the same animal is important to get a complete assessment of cardiac function. In this protocol, a closed chest approach to cardiac catheterization consistent with the way catheterization is performed in patients is adopted in mice. While challenging, the closed chest strategy is a more physiological approach, because opening the chest results in major changes in preload and afterload that create artifacts, most notably a fall in systemic blood pressure. While high-resolution echocardiography is used to assess rodents, cardiac catheterization is invaluable, particularly when assessing diastolic pressures in both ventricles.
Described here is a procedure to perform invasive, closed chest, sequential left and right ventricular pressure-volume (PV) loops in the same animal. PV loops are acquired using&#160;admittance technology with a mouse pressure-volume catheter and pressure-volume system acquisition. The procedure is described, beginning with the neck dissection, which is required to access the right jugular vein and the right carotid artery, to the insertion and positioning of the catheter, and finally the data acquisition. Then, the criteria required to ensure the acquisition of high-quality PV loops are discussed. Finally, the analysis of the left and right ventricular PV loops and the different hemodynamic parameters available to quantify systolic and diastolic ventricular function are briefly described.

Presented here is a protocol to assess biventricular heart function in mice by generating pressure-volume (PV) loops from the right and left ventricle in the same animal using closed chest catheterization. The focus is on the technical aspect of surgery and data acquisition.

小鼠闭胸导管插入术对心功能和压力-容积环的双心室评估

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) ...

Cardiac Response to &#946;-Adrenergic Stimulation Determined by Pressure-Volume Loop Analysis

Determination of the cardiac function is a robust endpoint analysis in animal models of cardiovascular diseases in order to characterize effects of specific treatments on the heart. Due to the feasibility of genetic manipulations the mouse has become the most common mammalian animal model to study cardiac function and to search for new potential therapeutic targets. Here we describe a protocol to determine cardiac function&#160;in vivo using pressure-volume loop measurements and analysis during basal conditions and under &#946;-adrenergic stimulation by intravenous infusion of increasing concentrations of isoproterenol. We provide a refined protocol including ventilation support taking into account the positive end-expiratory pressure to ameliorate negative effects during open-chest measurements, and potent analgesia (Buprenorphine) to avoid uncontrollable myocardial stress evoked by pain during the procedure. All together the detailed description of the procedure and discussion about possible pitfalls enables highly standardized and reproducible pressure-volume loop analysis, reducing the exclusion of animals from the experimental cohort by preventing possible methodological bias.

Here we describe a cardiac pressure-volume loop analysis under increasing doses of intravenously infused isoproterenol to determine the intrinsic cardiac function and the &#946;-adrenergic reserve in mice. We use a modified open-chest approach for the pressure-volume loop measurements, in which we include ventilation with positive end-expiratory pressure.

通过压力-体积环路分析确定心脏对β肾上腺素能刺激的反应

Determination of the cardiac function is a robust endpoint analysis in animal models of cardiovascular diseases in order to characterize effects of ...

Closed Chest Biventricular Pressure-Volume Loop Recordings with Admittance Catheters in a Porcine Model

Pressure-volume (PV) loop recording enables the state-of-the-art investigation of load-independent variables of ventricular performance. Uni-ventricular evaluation is often performed in preclinical research. However, the right and left ventricles exert functional interdependence due to their parallel and serial connections, encouraging simultaneous evaluation of both ventricles. Furthermore, various pharmacological interventions may affect the ventricles and their preloads and afterloads differently. 
We describe our closed chest approach to admittance-based bi-ventricular PV loop recordings in a porcine model of acute right ventricular (RV) overload. We utilize minimally invasive techniques with all vascular accesses guided by ultrasound. PV catheters are positioned, under fluoroscopic guidance, to avoid thoracotomy in animals, as the closed chest approach maintains the relevant cardiopulmonary physiology. The admittance technology provides real-time PV loop recordings without the need for post-hoc processing. Furthermore, we explain some essential troubleshooting steps during critical timepoints of the presented procedure. 
The presented protocol is a reproducible and physiologically relevant approach to obtain a bi-ventricular cardiac PV loop recording in a large animal model. This can be applied to a large variety of cardiovascular animal research.

Here we present a closed chest approach to admittance-based bi-ventricular pressure-volume loop recordings in pigs with acute right ventricular dysfunction.

猪模型中闭合胸部双心室压力-体积循环记录与导管

Pressure-volume (PV) loop recording enables the state-of-the-art investigation of load-independent variables of ventricular performance. Uni-ventricular ...

Measuring Pressure Volume Loops in the Mouse

Understanding the causes and progression of heart disease presents a significant challenge to the biomedical community. The genetic flexibility of the mouse provides great potential to explore cardiac function at the molecular level. The mouse&#39;s small size does present some challenges in regards to performing detailed cardiac phenotyping. Miniaturization and other advancements in technology have made many methods of cardiac assessment possible in the mouse. Of these, the simultaneous collection of pressure and volume data provides a detailed picture of cardiac function that is not available through any other modality. Here a detailed procedure for the collection of pressure-volume loop data is described. Included is a discussion of the principles underlying the measurements and the potential sources of error. Anesthetic management and surgical approaches are discussed in great detail as they are both critical to obtaining high quality hemodynamic measurements. The principles of hemodynamic protocol development and relevant aspects of data analysis are also addressed.

This manuscript describes a detailed protocol for the collection of pressure-volume data from the mouse.

测量压力容量环中的鼠标

Understanding the causes and progression of heart disease presents a significant challenge to the biomedical community. The genetic flexibility of the ...

使用压力-体积电导技术监测大鼠的心脏功能

Real-Time Detection of Ferulic Acid Effects on Rat Left Ventricle Using Pressure-Volume Conductivity Catheter

Decreased cardiac function can have a negative impact on other organs. The left ventricular pressure-volume relationship is considered to be a valid method for evaluating cardiac function. Real-time monitoring of cardiac function is important for drug evaluation. Under closed-chest conditions, the miniature transducer, which is an important component of the pressure-volume catheter, enters the left ventricle of the rat through the right carotid artery. The device visualizes the changes in cardiac function during the experiment in the form of a pressure-volume loop. The actual volume of the ventricle is calculated by altering the conductivity of the blood by injecting 50 &#181;L of a 20% sodium chloride solution into the rat's left jugular vein. The actual volume of the rat's ventricular cavity is calculated by measuring the conductivity of the blood in a known volume using a pressure-volume conductance catheter. This protocol allows for continuous observation of the effects of drugs on the heart and will promote the rationale for the use of specialty ethnic drugs in cardiovascular disease.

作者聚焦：压力-体积环测量方法在心血管研究中的优势

This protocol describes a method for measuring left ventricular pressure and volume using the pressure-volume conductance technique. This method enables continuous real-time monitoring of the effects of drugs on the heart.

使用压力-容积电导导管实时检测阿魏酸对大鼠左心室的影响

Decreased cardiac function can have a negative impact on other organs. The left ventricular pressure-volume relationship is considered to be a valid ...

心脏压力容量环分析小鼠使用电导导管

摘要

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使用压力-容积电导导管实时检测阿魏酸对大鼠左心室的影响

使用压力-容积电导导管实时检测阿魏酸对大鼠左心室的影响

心脏压力容量环分析小鼠使用电导导管

摘要

探索更多视频

心导​​管在小鼠测量压力体积的关系:调查的影响鲍迪奇

膜片钳和灌注技术研究离子通道的表达爪蟾卵母细胞

肺动脉高压的啮齿动物模型的血流动力学特性

生物人类免疫缺陷小鼠的微血管网络

小鼠闭胸导管插入术对心功能和压力-容积环的双心室评估

通过压力-体积环路分析确定心脏对β肾上腺素能刺激的反应

猪模型中闭合胸部双心室压力-体积循环记录与导管

测量压力容量环中的鼠标

使用压力-容积电导导管实时检测阿魏酸对大鼠左心室的影响

使用压力-容积电导导管实时检测阿魏酸对大鼠左心室的影响

心导管在小鼠测量压力体积的关系:调查的影响鲍迪奇