作者承认以下资金来源: 否则 Kröner-费森尤斯-基金会 (Tienush Rassaf);Hans 和格蒂 Fischer 基金会 (Tienush Rassaf), 补助金从医学教职员, 大学杜伊斯堡-埃森, 德国 (Tienush Rassaf, 米歇尔);Grimmke-基金会 (基督 Rammos)。

所有的实验都是按照和遵守所有相关的条例 (《欧洲保护用于实验和其他科学目的的脊椎动物的公约》 (指令 2010/63/欧盟) 完成的, 动物护理在符合机构准则。所有实验都是在6月龄的雄性 C57BL/6JRj 小鼠身上进行的。
1. 准备
<ol><li>准备一个外科显微镜和一个加热垫, 以及一个直肠探针来监测体温。清洁和消毒所有手术器械。</li>
	<li>为血管结扎、5厘米6-0 聚丙烯螺纹和2毫米硅管准备2件 10 cm 5-0 丝线, 用于结扎 LCA。</li>
	<li>准备 PV 导管校准试管加热到37摄氏度, 并准备100µL 哈密尔顿注射器填充15% 氯化钠 (氯化钠) 在 H2O 用于生理盐水校准。</li>
	<li>将 PV 导管 (3 厘米, 1.4 F) 放在37摄氏度预加热0.9% 氯化钠在 H2O (盐水) 至少30分钟之前测量。将导管连接到数据采集装置, 并将设备连接到模拟/数字转换器。将两个设备连接到计算机。</li>
	<li>设置软件。按照软件引导的工作流8的要求执行软件引导的压力校准和电导校准。</li>
</ol>2. 麻醉和镇痛
<ol><li>麻醉小鼠使用氯胺酮100毫克/千克体重和盐酸甲苯噻嗪10毫克/千克体重的腹腔注射。在初/R 手术, 管理0.05 毫克/千克体重丁丙诺啡腹腔保持镇痛。</li>
	<li>10分钟后, 使用20克静脉注射 (iv) 导管进行气管插管, 并用40% 氧 (O2) 和 2% (v) 异氟醚对小鼠进行通气。设置适当的通风参数 (例如, 220 µL 冲程体积, 150/分钟 25-30 克 C57BL/6JRj 鼠标)。</li>
	<li>通过直肠探头连续监测体温。将鼠标固定在加热板上, 头部指向调查员。小鼠正常体温为 36.5-38 摄氏度。通过调整加热板温度, 保持体温在1度以内。</li>
</ol>3. 左心室插管
<ol><li>用三 betadine 和70% 醇交替磨砂消毒胸部和颈部。 等待皮肤消毒剂干燥。用小动物剃须系统取出胸毛。</li>
	<li>使用小手术剪刀, 在底部唇下对胸骨执行10毫米纵中间切口5毫米。</li>
	<li>用镊子对颌下腺的左、右部分进行钝性解剖。在右 paratracheal 区域分离肌肉和脂肪组织, 以暴露右社区的颈动脉。将该血管从结缔组织中分离出来, 总长度为 5-10 毫米, 方法是通过仔细的钝性准备, 连同一条弯曲的镊子。 注意: 避免在任何时候对迷走神经或颈动脉体进行机械操作, 因为这会导致严重的低血压和心动过缓。</li>
	<li>把两条准备好的丝线递给船下。结扎的远端血管有一个紧密的结, 并放置一个松散的结在近暴露的区域仍然允许通过导管。</li>
	<li>固定在小鼠头部旁边的颅骨 (紧) 结的螺纹, 以便在容器上施加轻的张力, 因为这将促进导管的引入。将止血血管钳放在松散结的近端血管上, 可逆地阻断血流。</li>
	<li>在颅骨结上进行楔形切口1毫米, 用微剪刀打开容器。 注: 一小滴血将表明这一步骤的正确执行。</li>
	<li>小心插入导管10毫米. 开始记录导管数据。 注意: 用镊子伸展切口可以使这个过程更容易。</li>
	<li>提取血管钳。在切口添加 1-2 滴生理盐水, 以促进导管运动。继续介绍导管大约另10毫米。通过与传感器尖端的近端结, 小心地固定结, 以防止血液回流旁边的导管较薄的部分, 而不损害导管运动。 注: 导管顶端的传感器大小可防止提取血管钳时血液回流。</li>
	<li>轻轻地继续插入导管, 直到压力分析显示动脉血压剖面表明导管放置在主动脉 (图 3A)。 注: 导管到达主动脉瓣的导管将通过光阻和脉冲同步运动来表示。</li>
	<li>当遇到阻力试图通过主动脉瓣, 拉导管回到5毫米和再次前进, 直到 LV 插管将表明在 PV 分析的变化, 因为舒张压将达到 0-20 mmHg (图 3B)。注意音量监测的变化, 以进一步确认传感器尖端的左心室位置 (图 3C)。紧固近端结以防止导管运动。</li>
</ol>4. 缺血/再灌注手术
<ol><li>从胸骨向左腋窝进行皮肤切口, 总长度为15毫米. 进行钝性准备的两个肌肉层, 直到肋骨可以可视化。</li>
	<li>切开胸腔通过切口在第三和第四左肋骨之间。使用手术钩获得心包。切除心脏上方的心包。在继续进行 LCA 结扎之前, 等待三十年代不接触动物记录 PV 数据进行有效分析。</li>
	<li>定位在左耳廓下出现的 LCA, 并在心脏左侧下降朝向顶点。用6-0 聚丙烯缝合线将动脉围在左耳廓下方2毫米的环状。在循环下放置一个小的硅管, 并在上面放置一个紧的结。 注: 远端心肌变灰对 LCA 闭塞6起积极控制作用。I/R 手术应在5分钟内独立于手术调查员进行。</li>
	<li>以1毫米的长度切割缝线。松开手术钩, 并手动关闭切口上方的肌肉层。连续记录 PV 数据时等待45分钟。</li>
	<li>45分钟后, 重新打开切口, 取出硅管以诱导再灌注。记录其他20分钟的数据。 注意: 在缺血前看到的红色颜色的变化表明成功再灌注。</li>
</ol>5. 校准
注: 光伏导管系统的校准包括4个强制步骤, 其中两个必须在测量后执行。每次试验后应重复校准, 以确保有效的结果。
<ol><li>在实验前进行压力校准和电导校准, 如步骤1.5 所述。</li>
	<li>在实验结束后, 当导管仍放在左心室时, 执行生理盐水校准。在准备区域内定位颈动脉右颈静脉侧。在记录数据时,通过哈密尔顿注射器在 H2O 注射10µL 25% 氯化钠。</li>
	<li>通过在卷曲线中突出显示提升相位来计算使用采集软件的校准 (图 5C)。重复此过程总共3次。通过使用血管钳快速压缩穿刺, 避免在注射器取出后失血。</li>
	<li>通过对标准化卷的分析, 进行容积校准, 以校准容积数据的采集。获得大约500µL 小鼠血液从心脏穿刺与轻微血气1毫升注射器 (例如, 5 µL 每 200 IE 肝素)。拉回 PV 导管 10-15 毫米, 以避免损坏导管。</li>
	<li>将获得的血液填入37摄氏度预加热校准试管 (图 5A)。避免气泡, 因为它可能会干扰结果。将导管尖端添加到每个井中并记录数据。通过软件引导分析获得标准曲线 (图 5B)。重复该过程总共3次。</li>
	<li>弄死小鼠放血或颈椎脱位, 而充分的异氟醚麻醉始终保持。</li>
</ol>6. 数据分析
<ol><li>完成校准步骤后, 执行软件引导的数据分析。因此, 在PV 工作流的分析部分中, 突出显示相应的部分 (至少十个周期), 并执行基线分析。排除因通风或操作而有偏差的循环 (图 3D)。</li>
	<li>进行 PV 基线分析之前, 主动脉瓣 (仅动脉压力), 立即和之后的 LCA 闭塞。进行 PV 基线分析, 并在缺血和再灌注后5分钟的时间间隔进行。在实验结束后, 对左心室 (动脉压) 导管撤回后的压力数据进行分析。</li>
	<li>分析至少10个周期以避免取样误差。当在通风条件下, 对所获得的值有强烈的干扰时, 可以考虑5秒内通风的瞬态中断。</li>
	<li>使用在基线分析中计算的以下参数 (图 3D) 来描述 LV 函数:<ol>
<li>描边音量 (µL)</li>
		<li>射出分数: 中风体积/端舒张容积 (%)</li>
		<li>心脏输出: 中风体积 * 心率 (µL/分钟)</li>
		<li>心脏指数: 心脏输出/体表面积 (µL/(分钟 * cm²)</li>
		<li>冲程工作: PV 曲线的内部区域 (mmHg * µL)</li>
		<li>最大压力 (Pmax);平均压力 (Pmean)</li>
		<li>最大 dP/dt (mmHg) 作为低压收缩功能的参数</li>
		<li>最小 dP/dt (mmHg/秒) 作为 LV 合规性的参数</li>
		<li>等容松弛时间常数: 头 (ms)</li>
	</ol>
</li>
</ol>

<ol>
	<li>Sanchis-Gomar, F., Perez-Quilis, C., Leischik, R., Lucia, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+of+coronary+heart+disease+and+acute+coronary+syndrome.">Epidemiology of coronary heart disease and acute coronary syndrome.</a> Annals of Translational Medicine. 4 (13), 256 (2016).</li><li>Anderson, J. L., Morrow, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+Myocardial+Infarction.">Acute Myocardial Infarction.</a> New England Journal of Medicine. 376 (21), 2053-2064 (2017).</li><li>McNamara, R. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predicting+in-hospital+mortality+in+patients+with+acute+myocardial+infarction.">Predicting in-hospital mortality in patients with acute myocardial infarction.</a> Journal of the American College of Cardiology. 68 (6), 626-635 (2016).</li><li>Kurian, G. A., Rajagopal, R., Vedantham, S., Rajesh, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Role+of+Oxidative+Stress+in+Myocardial+Ischemia+and+Reperfusion+Injury+and+Remodeling:+Revisited.">The Role of Oxidative Stress in Myocardial Ischemia and Reperfusion Injury and Remodeling: Revisited.</a> Oxidative Medicine and Cellular Longevity. , (2016).</li><li>Turer, A. T., Hill, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathogenesis+of+myocardial+ischemia-reperfusion+injury+and+rationale+for+therapy.">Pathogenesis of myocardial ischemia-reperfusion injury and rationale for therapy.</a> American Journal of Cardiology. 106 (3), 360-368 (2010).</li><li>Totzeck, M., Hendgen-Cotta, U. B., French, B. A., Rassaf, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+practical+approach+to+remote+ischemic+preconditioning+and+ischemic+preconditioning+against+myocardial+ischemia/reperfusion+injury.">A practical approach to remote ischemic preconditioning and ischemic preconditioning against myocardial ischemia/reperfusion injury.</a> Journal of Biological Methods. 3 (4), (2016).</li><li>Respress, J. L., Wehrens, X. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transthoracic+echocardiography+in+mice.">Transthoracic echocardiography in mice.</a> Journal of Visualized Experiments. (39), (2010).</li><li>Pacher, P., Nagayama, T., Mukhopadhyay, P., Batkai, S., Kass, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+cardiac+function+using+pressure-volume+conductance+catheter+technique+in+mice+and+rats.">Measurement of cardiac function using pressure-volume conductance catheter technique in mice and rats.</a> Nature Protocols. 3 (9), 1422-1434 (2008).</li><li>Zhang, B., Davis, J. P., Ziolo, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+catheterization+in+mice+to+measure+the+pressure+volume+relationship:+Investigating+the+Bowditch+effect.">Cardiac catheterization in mice to measure the pressure volume relationship: Investigating the Bowditch effect.</a> Journal of Visualized Experiments. (100), e52618 (2015).</li><li>Rossello, X., Hall, A. R., Bell, R. M., Yellon, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+the+Langendorff+perfused+isolated+mouse+heart+model+of+global+ischemia-reperfusion+injury:+Impact+of+ischemia+and+reperfusion+length+on+infarct+size+and+LDH+release.">Characterization of the Langendorff perfused isolated mouse heart model of global ischemia-reperfusion injury: Impact of ischemia and reperfusion length on infarct size and LDH release.</a> Journal of Cardiovascular Pharmacology and Therapeutics. 21 (3), 286-295 (2016).</li><li>Task Force on the management of ST-segment elevation acute myocardial infarction of the European Society of Cardiology (ESC). <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ESC+Guidelines+for+the+management+of+acute+myocardial+infarction+in+patients+presenting+with+ST-segment+elevation.">ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation.</a> European Heart Journal. 33 (20), 2569-2619 (2012).</li><li>Shigemitsu, O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+myocardial+infarction+due+to+left+main+coronary+artery+occlusion.+Therapeutic+strategy.">Acute myocardial infarction due to left main coronary artery occlusion. Therapeutic strategy.</a> Japanese Journal of Thoracic and Cardiovascular Surgery. 50 (4), 146-151 (2002).</li></ol>

作者没有什么可透露的。

对急性心肌梗死的 lv 血流动力学进行光电监测, 是实时评价心源性休克和左心室损伤的 lv 功能的一种新方法。PV 导管可以提供一个广泛的参数, 关于 LV 收缩和舒张功能。除了通常由超声心动图或 MRI (腔容积, EF, 中风体积和心脏输出) 获得的 lv 容积参数外, PV 分析通过同时提供 lv 收缩的措施, 产生一个更完整的 lv 功能剖面性能 (收缩力 dp/dt, 中风工作) 和 LV 遵约 (dp/dt, 头) 作为一个参数的舒张...

心血管疾病是西方文明中最常见的死亡原因1。急性心肌梗死是一个关键事件, 这是与高急性和慢性死亡率2。即使通过急诊经皮冠状动脉介入术 (PCI) 实现血管重建, 死亡率仍然很高, 特别是在48小时后, 急性心肌梗塞患者出现症状后3。急性左心室功能降低引起的心源性休克是3例住院死亡率的主要原因。这种早期的 LV 功能降低是由于缺血再灌注后心肌损伤所致。这种所谓的缺血/再灌注 (I/R) 损伤是介导的细胞代谢物的变化, 如夸大产生的活性氧物种4,5。
为了探索可能的保护机制, 导致在临床前设置的心肌损害减少, 可靠的鼠标模型是必不可少的, 包括评估的方法后, 左/R LV 功能6。在这一背景下, 经胸超声心动图7和磁共振成像 (MRI)6被广泛用于功能分型8,9。然而, 这些方法不适用于评估严重的 lv 功能障碍和心源性休克的持续急性心肌梗死, 不能直接显示有关 LV 压力的数据。在体外试验中使用隔离心脏的 Langendorff 装置提供了有关早期 I./R 损伤10的潜在 pathomechanisms 的信息。这种方法是有限的, 因为它无法重现体内的适应性机制, 如调节自主神经系统或激素调节和酸碱平衡。目前尚无方法可用于完全功能分型的心源性休克和左心室功能障碍在持续性心肌 I./R 损伤。
一种同步的方法, 结合压力容积 (PV) 插管和瞬态手术左冠状动脉主干 (LCA) 闭塞可能是有益的, 但技术上的挑战。稳定的源于血流动力学在我/R 损伤是必不可少的有效的结果, 因为不稳定的麻醉或失血可能严重影响的结果。采用低压光伏插管和瞬态 LCA 阻断技术对分型损伤的血流动力学进行研究, 可为急性心肌梗死患者心源性休克和 LV 功能障碍提供新的见解, 并作为今后分析心肌。

<table><tbody><tr><td>Betaisodona Loesung</td><td>Mundipharma</td><td>4162-1606/89x30mm</td><td>Povidon-Iod</td></tr><tr><td>Calibration cuvette</td><td>Millar instruments</td><td>910-1049</td><td>Calibration cuvette</td></tr><tr><td>Contura professional hair trimmer</td><td>Wella</td><td>HS-60</td><td>Small animal shaving system</td></tr><tr><td>Eclipse Needle 27G</td><td>BD</td><td>REF 305770</td><td>27G needle</td></tr><tr><td>Forceps</td><td>FST</td><td>11203-25, 11069-08, 11616-15, 11506-12, 11051-10</td><td>Surgical forceps</td></tr><tr><td>Forceps</td><td>Aesculap Braun</td><td>BN731R, BD 311R</td><td>Surgical forceps</td></tr><tr><td>Foris FS2434</td><td>Eizo</td><td>0FTD2033</td><td>Monitor</td></tr><tr><td>Hamilton Syringe 100 &amp;micro;l needle</td><td>Hamilton</td><td>80621</td><td>100&amp;micro;l syringe with needle</td></tr><tr><td>Heated Small animal OP table</td><td>Harvard Apparatus</td><td>15001</td><td>Heated OP table</td></tr><tr><td>Heparin-Natrium 25000</td><td>Ratiopharm</td><td>N68542.04</td><td>Heparin</td></tr><tr><td>Ketamin 10% 100 mg/ml</td><td>bela-pharm</td><td>FS1670041</td><td>Ketamin</td></tr><tr><td>Labchart Pro 8 + Pro modules</td><td>AD Instruments</td><td>MLS260/8</td><td>PV data analysis software</td></tr><tr><td>LAS EZ</td><td>Leica</td><td>LAS EZ</td><td>Microscope camera software</td></tr><tr><td>Leica IC80 HD</td><td>Leica</td><td>IC80 HD</td><td>Microscope camera</td></tr><tr><td>Leica M80</td><td>Leica</td><td>M80</td><td>Microscope</td></tr><tr><td>Micro-tip catheter transducer</td><td>Millar instruments</td><td>SPR-839</td><td>PV catheter</td></tr><tr><td>MiniVent</td><td>Harvard Apparatus</td><td>845</td><td>ventilation</td></tr><tr><td>MPVS Ultra</td><td>Millar instruments</td><td>PL3508B48/M</td><td>PV catheter data acquisition device</td></tr><tr><td>Octenisept</td><td>Sch&amp;uuml;lke</td><td>20000832-A</td><td>disinfectant</td></tr><tr><td>Plastipak 1ml</td><td>PD</td><td>REF 303172</td><td>1ml syringe</td></tr><tr><td>PowerLab 8/35</td><td>AD Instruments</td><td>PL3508</td><td>analog/digital converter</td></tr><tr><td>Prolene 6-0</td><td>Ethicon</td><td>XNEH7814.P31</td><td>Polypropylene suture</td></tr><tr><td>Retraction Kit</td><td>FST</td><td>18200-20</td><td>retraction of surgical situs</td></tr><tr><td>Seraflex 5-0</td><td>Naila</td><td>IC108000</td><td>silk suture</td></tr><tr><td>Small and micro-scissors</td><td>FST Essen</td><td>14059-11, 15007-08, 14064-11</td><td>Surgical scissors</td></tr><tr><td>Small silicon tube</td><td>Reichelt Chemietechnik</td><td></td><td>tube for LCA occlusion</td></tr><tr><td>Sodium Chloride</td><td>Sigma-Aldrich</td><td>S7653</td><td>Sodium Chloride</td></tr><tr><td>testo 108</td><td>testo</td><td>5631080</td><td>rectal thermometer</td></tr><tr><td>Thinkcentre desktop computer</td><td>Lenovo</td><td>PC0EJS2V</td><td>Computer</td></tr><tr><td>Vasofix Safety 20G</td><td>Braun</td><td>4269110S-01</td><td>intubation catheter</td></tr><tr><td>Windows 10</td><td>Microsoft</td><td>KW9-00240</td><td>Operating system</td></tr><tr><td>Xylazin 2%</td><td>Ceva</td><td>6324464.00.00</td><td>Xylazine hydrochloride</td></tr></tbody></table>

real-time pressure-volume analysis of acute myocardial infarction in mice

急性心肌梗死可导致急性心力衰竭和心源性休克。血流动力学的评估对于评估任何针对急性左心室 (LV) 功能障碍的潜在治疗方法都是至关重要的。目前的成像方式 (例如, 超声心动图和磁共振成像) 有几个局限性, 因为 LV 压力的数据不能直接测量。lv 导管在冠状动脉闭塞小鼠中的应用, 可作为实时评价 lv 功能的一种新方法。
在手术开始时, 小鼠被麻醉后气管插管。对于 LV 插管, 右颈动脉通过中颈部切口暴露。导管被引入并放置在 LV 腔内。左开胸术进行, 左主干冠状动脉 (LCA) 结扎。为诱导再灌注, 缝线在45分钟后释放, 在任何时候都记录了压力容积数据。
结扎的 LCA 导致 LV 收缩功能下降, 这证明了30% 减少中风体积, LV 弹射分数 (EF) 和心脏输出。最大 dp/dt 作为一个参数的 LV 收缩力也显著降低, 舒张功能严重受损 (最小 dP/dt-40%)。再灌注在20分钟期间没有导致 LV 作用的完全恢复。
实时压力容积分析作为监测急性心肌梗死小鼠心功能的有效方法。保持稳定的麻醉和规范化的手术方法对确保有效的结果至关重要。急性心肌梗死的早期阶段对发病率和死亡率有重要意义, 该方法可为心肌新策略的临床前评价提供有益的借鉴。

经低压插管后, 45 分钟可逆性 LCA 结扎术后再灌注10分钟。PV 数据在任何时候都被记录下来 (图 1)。
通过获得特征 LV pv 图 (图 2A), 确定了 pv 导管的正确位置。LV 导管放置显示典型的心室压力范围, 至少 0-20 mmHg, 而在主动脉中的 PV 导管假放置将显示一个典型的动脉压力曲线, 最小压力为...

Watch this Scientific Journal Video about Real-time Pressure-volume Analysis of Acute Myocardial Infarction in Mice at JoVE.com

Real-time Pressure-volume Analysis of Acute Myocardial Infarction in Mice

小鼠急性心肌梗死诱发左心室 (LV) 功能的急性但不完全特征性改变。lv 导管在冠状动脉闭塞小鼠中的应用是一种实时评价 lv 功能的新方法。

小鼠急性心肌梗死的实时压力容积分析

Acute myocardial infarction can lead to acute heart failure and cardiogenic shock. The evaluation of hemodynamics is critical for the evaluation of any ...

real-time-pressure-volume-analysis-acute-myocardial-infarction

Research

JoVE Journal

Medicine

9.0K 次观看.  University Hospital Essen. 小鼠急性心肌梗死诱发左心室 (LV) 功能的急性但不完全特征性改变。lv 导管在冠状动脉闭塞小鼠中的应用是一种实时评价 lv 功能的新方法。

视频: Real-time Pressure-volume Analysis of Acute Myocardial Infarction in Mice

MRI and PET in Mouse Models of Myocardial Infarction

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ideal model for testing novel therapeutic strategies.
In vivo magnetic resonance imaging (MRI) gives excellent views of the heart noninvasively with clear anatomical detail, which can be used for accurate functional assessment. Contrast agents can provide basic measures of tissue viability but these are nonspecific. Positron emission tomography (PET) is a complementary technique that is highly specific for molecular imaging, but lacks the anatomical detail of MRI. Used together, these techniques offer a sensitive, specific and quantitative tool for the assessment of the heart in disease and recovery following treatment.
In this paper we explain how these methods are carried out in mouse models of acute myocardial infarction. The procedures described here were designed for the assessment of putative protective drug treatments. We used MRI to measure systolic function and infarct size with late gadolinium enhancement, and PET with fluorodeoxyglucose (FDG) to assess metabolic function in the infarcted region. The paper focuses on practical aspects such as slice planning, accurate gating, drug delivery, segmentation of images, and multimodal coregistration. The methods presented here achieve good repeatability and accuracy maintaining a high throughput.

We describe how to perform MRI and PET imaging of the mouse heart. The protocol is tailored to assess treatment efficacy in models of myocardial infarction and heart failure.

MRI和PET心肌梗死小鼠模型

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ...

科研

医学

A Murine Model of Myocardial Ischemia-reperfusion Injury through Ligation of the Left Anterior Descending Artery

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms at work during MI and developing effective therapeutic approaches requires methodology to reproducibly simulate the clinical incidence and reflect the pathophysiological changes associated with MI. Here, we describe a surgical method to induce MI in mouse models that can be used for short-term ischemia-reperfusion (I/R) injury as well as permanent ligation. The major advantage of this method is to facilitate location of the left anterior descending artery (LAD) to allow for accurate ligation of this artery to induce ischemia in the left ventricle of the mouse heart. Accurate positioning of the ligature on the LAD increases reproducibility of infarct size and thus produces more reliable results. Greater precision in placement of the ligature will improve the standard surgical approaches to simulate MI in mice, thus reducing the number of experimental animals necessary for statistically relevant studies and improving our understanding of the mechanisms producing cardiac dysfunction following MI. This mouse model of MI is also useful for the preclinical testing of treatments targeting myocardial damage following MI.

We introduce a surgical method to induce experimental ischemia/reperfusion (I/R) injury to simulate myocardial infarction (MI) in mouse models that allows for more clarity in positioning of the ligation on the left anterior descending artery (LAD) to increase the reproducibility of MI experiments in mice.

心肌缺血再灌注损伤的通过左前降支结扎小鼠模型

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms ...

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD).

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

This method outlines the use of Quantum Micro-Computed Tomography (MicroCT) to assess cardiac morphology, function, perfusion, metabolism and viability with iodinated contrast agent in mice with experimentally-induced myocardial ischemia. The technique can be applied for non-destructive high-throughput longitudinal in vivo imaging of various animal models of human heart disease.

在心肌结构，功能的体内定量评估，灌注与活力使用心脏微型计算机断层扫描

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that ...

生物工程

Minimal Invasive Surgical Procedure of Inducing Myocardial Infarction in Mice

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last decades. For clarification of the underlying mechanisms and the development of new therapeutic strategies, the availability of valid animal models are mandatory. Since we need new insights into pathomechanisms of cardiovascular diseases under in vivo conditions to combat myocardial infarction, the validity of the animal model is a crucial aspect. However, protection of animals are highly relevant in this context. Therefore, we establish a minimally invasive and simple model of myocardial infarction in mice, which assures a high reproducibility and survival rate of animals. Thus, this models fulfils the requirements of the 3R principle (Replacement, Refinement and Reduction) for animal experiments and assure the scientific information needed for further developing of therapeutical strategies for cardiovascular diseases.

A highly reproducible model for myocardial infarction in mice with minimal invasive manipulations is described. The model can be easily performed, resulting in a high reproducibility and survival rate. Thus, the described model will reduce the number of required animals as requested by the 3R principle (Replacement, Refinement and Reduction).

在诱导小鼠心肌梗死的微创手术过程

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last ...

Permanent Ligation of the Left Anterior Descending Coronary Artery in Mice: A Model of Post-myocardial Infarction Remodelling and Heart Failure

Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It is characterized by fluid retention, shortness of breath, and fatigue, in particular on exertion. Heart failure is a growing public health problem, the leading cause of hospitalization, and a major cause of mortality. Ischemic heart disease is the main cause of heart failure.
Ventricular remodelling refers to changes in structure, size, and shape of the left ventricle. This architectural remodelling of the left ventricle is induced by injury (e.g., myocardial infarction), by pressure overload (e.g., systemic arterial hypertension or aortic stenosis), or by volume overload. Since ventricular remodelling affects wall stress, it has a profound impact on cardiac function and on the development of heart failure. A model of permanent ligation of the left anterior descending coronary artery in mice is used to investigate ventricular remodelling and cardiac function post-myocardial infarction. This model is fundamentally different in terms of objectives and pathophysiological relevance compared to the model of transient ligation of the left anterior descending coronary artery. In this latter model of ischemia/reperfusion injury, the initial extent of the infarct may be modulated by factors that affect myocardial salvage following reperfusion. In contrast, the infarct area at 24 hr after permanent ligation of the left anterior descending coronary artery is fixed. Cardiac function in this model will be affected by 1) the process of infarct expansion, infarct healing, and scar formation; and 2) the concomitant development of left ventricular dilatation, cardiac hypertrophy, and ventricular remodelling.
Besides the model of permanent ligation of the left anterior descending coronary artery, the technique of invasive hemodynamic measurements in mice is presented in detail.

Heart failure is the leading cause of hospitalization and a major cause of mortality. A model of permanent ligation of the left anterior descending coronary artery in mice is applied to investigate ventricular remodelling and cardiac dysfunction post-myocardial infarction. The technique of invasive hemodynamic measurements in mice is presented.

左冠状动脉前降支的小鼠结扎:对心肌梗死后重塑和心衰模型

Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It ...

Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are therefore required to confine cardiac damage, promote survival and reduce the disease burden of heart failure. Large animal experiments are an essential part in the translational process from experimental to clinical therapies. To optimize clinical translation, robust and representative outcome measures are mandatory. The present manuscript aims to address this need by describing the assessment of three clinically relevant outcome modalities in a pig acute myocardial infarction (AMI) model: infarct size in relation to area at risk (IS/AAR) staining, 3-dimensional transesophageal echocardiography (TEE) and admittance-based pressure-volume (PV) loops. Infarct size is the main determinant driving the transition from AMI to heart failure and can be quantified by IS/AAR staining. Echocardiography is a reliable and robust tool in the assessment of global and regional cardiac function in clinical cardiology. Here, a method for three-dimensional transesophageal echocardiography (3D-TEE) in pigs is provided. Extensive insight into cardiac performance can be obtained by admittance-based pressure-volume (PV) loops, including intrinsic parameters of myocardial function that are pre- and afterload independent. Combined with a clinically feasible experimental study protocol, these outcome measures provide researchers with essential information to determine whether novel therapeutic strategies could yield promising targets for future testing in clinical studies.

Reliable and accurate outcome assessment is the key for translation of preclinical therapies into clinical treatment. The current paper describes how to assess three clinically relevant primary outcome parameters of cardiac performance and damage in a pig acute myocardial infarction model.

急性心肌梗死的猪模型主要成果评估

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are ...

Murine Myocardial Infarction Model using Permanent Ligation of Left Anterior Descending Coronary Artery

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine models of MI with permanent ligation of left-anterior descending (LAD) coronary artery closely mimics MI in humans. Murine models benefit from the extensive genetic engineering available nowadays. Here we propose a reproducible murine surgical model of myocardial infarction by permanent LAD coronary ligation. Our technique comprises anesthesia with ketamine/xylazine that can be rapidly reversed by administration of an antagonist, intubation without tracheotomy for mechanical-assisted ventilation, ventilation with application of extrinsic positive end-expiratory pressure (PEEP) to avoid alveolar collapse, a thoracotomy method limiting to the minimum surgical lesions made to skeletal muscles, and lung inflation without thoracentesis. This method is sparsely invasive, reproducible and reduces post-surgery mortality and complications.

Herein we describe a surgical procedure showing how to achieve permanent ligation of the left-anterior descending coronary artery in mice. This model is of high relevance to investigate the pathophysiology of myocardial infarction and the concomitant biological processes.

使用左前部降冠动脉的永久结扎的月心肌梗死模型

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine ...

A Cryoinjury Model to Study Myocardial Infarction in the Mouse

The use of animal models is essential for developing new therapeutic strategies for acute coronary syndrome and its complications. In this article, we demonstrate a murine cryoinjury infarct model that generates precise infarct sizes with high reproducibility and replicability. In brief, after intubation and sternotomy of the animal, the heart is lifted from the thorax. The probe of a handheld liquid nitrogen delivery system is applied onto the myocardial wall to induce cryoinjury. Impaired ventricular function and electrical conduction can be monitored with echocardiography or optical mapping. Transmural myocardial remodeling of the infarcted area is characterized by collagen deposition and loss of cardiomyocytes. Compared to other models (e.g., LAD-ligation), this model utilizes a handheld liquid nitrogen delivery system to generate more uniform infarct sizes.

This article demonstrates a model to study cardiac remodeling after myocardial cryoinjury in mice.

研究小鼠心肌梗死的低温损伤模型

The use of animal models is essential for developing new therapeutic strategies for acute coronary syndrome and its complications. In this article, we ...

A Modified Simple Method for Induction of Myocardial Infarction in Mice

Myocardial infarction (MI) represents one of the leading causes of death. MI models are widely used for investigating the pathomechanisms of post-MI remodeling and evaluation of novel therapeutics. Different methods (e.g., isoproterenol treatment, cryoinjury, coronary artery ligation, etc.) have been used to induce MI. Compared with isoproterenol treatment and cryoinjury, coronary artery ligation may better reflect the ischemic response and chronic remodeling after MI. However, traditional methods for coronary ligation in mice are technically challenging. The current study describes a simple and efficient process for induction of MI in mice with readily available materials. The mouse chest skin was cut open under stable anesthesia. The heart was immediately externalized through the intercostal space after blunt separation of the pectoralis major and pectoralis minor. The left anterior descending branch (LAD) was ligated with a 6-0 suture 3 mm from its origin. Following LAD ligation, staining with 2,3,5-Triphenyltetrazolium chloride (TTC) indicated successful induction of MI and temporal changes of post-MI scar size. Meanwhile, survival analysis results showed overt mortality within 7 days after MI, mainly due to cardiac rupture. Moreover, post-MI echocardiographic assessment demonstrated successful induction of contractile dysfunction and ventricular remodeling. Once mastered, an MI model can be established in mice within 2-3 min with readily available materials.

Under adequate anesthesia, the mouse heart was externalized through the intercostal space, and myocardial infarction was successfully induced by ligating the left anterior descending artery (LAD) using materials readily available in most laboratories.

一种改良的小鼠心肌梗死诱导简易方法

Myocardial infarction (MI) represents one of the leading causes of death. MI models are widely used for investigating the pathomechanisms of post-MI ...

An Experimental Model of Myocardial Infarction for Studying Cardiac Repair and Remodeling in Knockout Mice

Cardiovascular disease is the most prevalent cause of death in Western countries, with acute myocardial infarction (MI) being the most prevalent form. This paper describes a protocol for studying the role of galectin 3 (Gal-3) in the temporal evolution of cardiac healing and remodeling in an experimental animal model of MI. 
The procedures described include an experimental model of MI with a permanent coronary ligature in male C57BL/6J (control) and Gal-3 knockout (KO) mice, an echocardiography procedure to study cardiac remodeling and systolic function in vivo, a histological evaluation of interstitial myocardial fibrosis with picrosirius red-stained and rhodamine-conjugated lectin-stained sections for studying myocyte hypertrophy by the cross-sectional area (MCSA), and the quantification of infarct size and cardiac remodeling (scar thinning, septum thickness, and expansion index) by planimetry in slices stained with Masson's trichrome and triphenyl tetrazolium chloride. Gal-3 KO mice with MI showed disrupted cardiac remodeling and an increase in the scar thinning ratio and the expansion index. At the onset of MI, myocardial function and cardiac remodeling were also severely affected. At 4 weeks post MI, the natural evolution of fibrosis in infarcted Gal-3 KO mice was also affected. 
In summary, the experimental model of MI is a suitable model for studying the temporal evolution of cardiac repair and remodeling in mice with the genetic deletion of Gal-3 and other animal models. The lack of Gal-3 affects the dynamics of cardiac repair and disrupts the evolution of cardiac remodeling and function after MI.

Here, we describe an experimental model of myocardial infarction, an echocardiography procedure to study cardiac remodeling and function, and procedures for quantifying fibrosis and hypertrophy in picrosirius red-stained and rhodamine-stained sections, as well as the infarct size and expansion index in slices stained with Masson's trichrome.

Cardiovascular disease is the most prevalent cause of death in Western countries, with acute myocardial infarction (MI) being the most prevalent form. ...