Name: improvement of a closed chest porcine myocardial infarction model by standardization of tissue and blood sampling procedures
Uploaded: 2018-03-12T14:30:00.000+00:00
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Description: Watch this Scientific Journal Video about Improvement of a Closed Chest Porcine Myocardial Infarction Model by Standardization of Tissue and Blood Sampling Procedures at JoVE.com

作者希望感谢基督教 Heinis 教授提供 FXIIa 抑制剂和各自的控制。我们还感谢伯尔尼大学生物医学研究系 Olgica Beslac、丹尼尔梅特勒和凯 Nettelbeck 的技术支持。席琳 Guillod 和 Rausch 从诊断, 介入和儿科放射科, 伯尔尼大学医院, Inselspital 提供支持的 x 光设备和技术。该项目由瑞士国家科学基金会320030_156193 项目资助。我们还要感谢伯尔尼大学医院通讯和营销 Reto Haenni 先生, Inselspital 为我们的实验录像录音。

1. 动物:
所有动物根据瑞士国家法律的指南对待。研究由伯尔尼的地方动物实验委员会批准 (允许 no。为 25/16)。
使用两个性别的大白猪 (~ 30 ~ 5 公斤)。将动物盲目分为两组, 一组接受笼 (80 kDa 蛋白酶) 抑制剂的 FXIIa 或治疗的选择, 另一种是不活跃的控制。
2. 外科手术 (图 1)
<ol><li>麻醉和动物的准备:
	<ol>
<li>在开始实验前, 动物的速度要快12小时。</li>
		<li>使用10毫升注射器在颈部注射20毫克/千克氯胺酮和2毫克/千克甲苯噻嗪。记录动物的体重和性别。</li>
		<li>通过注射0.5 毫克/千克咪达唑仑和0.05 毫克/千克阿托品入耳静脉, 诱发麻醉。用气管插管动物。</li>
		<li>使用呼吸机 (O2/空气 1:3, Sevorane 1.5%), 7-8 毫米气道管和过滤器维持麻醉的机械通气。调整被启发的氧气的分数 (不负担装卸2) 到35% 和潮汐容量到6-10 毫升/公斤。</li>
		<li>麻醉深度被评估为足够的没有任何马达或自主反应的鼻子捏。眼睑反射和下巴的语调不断监测, 以及针对松弛颚色调和没有眼睑反射。核心温度连续监测和维护常温 (38-38.5 °c) 是确保与被动升温 (隔离毛毯和温暖瓶)。</li>
		<li>解剖自由, 如前 Koudstaal 和他的同事所描述的步骤3-1 至 3-318, 颈动脉两侧和 cannulate 他们与7F 鞘。Cannulate 左颈静脉与7F 鞘静脉采血。</li>
		<li>管理一丸剂量250µg 芬太尼镇痛通过中心静脉线后250µg/小时作为持续静脉输液使用输液泵。在整个实验过程中, 用3导联心电图 (ECG)、动脉和中心静脉压力监测体温、心率和节律。</li>
		<li>使用标准采血管, 从静脉线提取以下基线血液样本: 5 毫升柠檬酸血浆和2.9 毫升 EDTA 血浆入各自的管子。离心机立即在 2000 x g 15 分钟4摄氏度。将2.9 毫升血液注入血清管, 并允许在室温下凝固30分钟, 离心前所述。</li>
		<li>整除200µL 血浆或血清为500µL 管, 并将所有样品保存在-80 摄氏度以供进一步分析。</li>
		<li>根据制造商的指示, 使用特殊的血气分析 (bga) 注射器从动脉线上提取0.5 毫升血液, 使用 bga 机测量 bga。</li>
		<li>使用标准的2毫升注射器从静脉线提取0.5 毫升血液, 并立即用30克针将其转移到 ACT 墨盒中。将填充的墨盒插入 ACT 机器, 根据制造商的说明测量凝固时间。有关时间点, 请参见图 2 。</li>
		<li>用2毫升注射器将5000普通肝素注入静脉内, 让动物在开始 MI 实验前稳定20分钟。</li>
		<li>监督行动每30-45 分钟, 如2.1.11 所述。注射2500普通肝素静脉注射, 如果行为是 < 180s。</li>
	</ol></li>
	<li>心肌梗塞实验
	<ol>
<li>使用标准的 C 臂透视设备 (冠状动脉造影程序, 角度, 12 帧每秒, ~ 70 伏)-或一个专门的血管造影系统-进行冠状动脉介入治疗。</li>
		<li>使用透视引导插入压力导管 (5F, 120 厘米) 通过先前放置鞘在左颈动脉。把它推进左心室。将压力导管连接到采集系统以记录左心室压力。在整个实验过程中, 采集系统需要连续计算和记录心率、压力、dp/dt 最大值 (左心室收缩率) 和 dp/dt 最小 (左心室松弛)。记录基线值为10分钟。</li>
		<li>插入一个 6F (100 厘米, EB3.75) 引导导管通过先前放置鞘进入右颈动脉。在 X 线引导下, 将其推进左冠状动脉, 达到左前降冠状动脉 (童子)。用20毫升注射器通过引导导管注射造影剂, 进行基线冠状动脉造影。 注: 通过人工压力进行对比介质的注入, 但也可以使用专用的动力喷油器系统。</li>
		<li>评估 X 线显示器上的小伙子大小, 选择合适的经皮冠状动脉介入治疗 (PCI) 导管大小。使用 PCI 气球的长度为15-25 毫米和直径在2和3.5 毫米之间取决于小伙子的大小。组装 PCI 导管和冠状动脉导丝 (F 014/J, 175 厘米)。用造影剂预填充的充气装置将 PCI 导管连接起来。 注意: 可以使用标尺直接在校准的显示器上测量童子直径, 然后相应地选择 PCI 气球的大小。</li>
		<li>将组装的系统从2.2.4 插入引导导管的腔内。推进导丝入小伙子, 直到它到达在小伙子的第二对角分支之外。</li>
		<li>使用透视的指导, 以推进 PCI 导管, 直到它到达大约在中间的小伙子。根据冠状动脉的解剖学选择 "小伙子阻断站点", 通常在第二次之后, 有时在第一个对角线分支 (图 3) 之后, 以使左心室的 AAR (LV) 有相似的百分比。 注: 阻断部位的选择取决于对角线分支的长度, 因而是由血液通过各自分支提供的组织面积。在一个长, 分岔的第一对角线分支的情况下, 封锁网站将在这之后。如果第一对角分支较短, 则在第二个对角线之后进行阻塞。</li>
		<li>取出导丝, 然后将充气装置中的压力增加到7-10 巴, 以充气 PCI 导管的气球, 并诱导心肌缺血1小时, 将不负担装卸2逐渐增加到50-60% 之间的15和40分钟的缺血。保持潮汐体积在6-10 毫升/千克。 注意: 本程序可减少 extrasystoles 的发生, 降低心室颤动的频率。</li>
		<li>记录 5-10 s 视频序列, 同时通过引导导管注射造影剂, 在启动缺血后, 对 PCI 导管的气球进行血管造影;重复10分钟的缺血后, 验证 PCI 导管的气球远端完全闭塞。</li>
		<li>密切监视动物, 立即检测和治疗 (2.2.10) 心律失常。心肌缺血诱导后, Extrasystoles 通常发生并增加20至40分钟之间的频率 (> 3/分钟)。如果发生这种情况, 轻轻地按摩两侧的颈部就在脸颊下面。在大多数情况下, 这将足以重新建立一个正常的心跳, 可能是通过刺激的迷走神经 baroreceptors 位于颈总动脉。</li>
		<li>如果心律失常进展为心室颤动, 使用外部, 双相除颤器重新建立窦节律。在应用休克前立即应用5-10 胸按压, 以便用含氧血填充冠状动脉, 然后用 150 J (30 公斤动物) 休克。</li>
		<li>如有必要, 重复 3rd冲击后将能量增加到 175 J。对较重的动物使用更高的能量设置。</li>
		<li>五分钟在缺血时间结束之前重复血液取样在 2.1. 8-2. 1.13 中提及。注射测试物质 (无论是笼 FXIIa 抑制剂或控制4毫克/千克, 这样做盲目) 静脉注射通过中心静脉线和冲洗线与20毫升生理盐水。</li>
		<li>提取一个血浆柠檬酸盐样品 (如2.1.8 和2.1.9 中提到) 4 分钟后, 注射的物质在2.2.12。</li>
		<li>执行血管造影 (2.2.3), 以确认小伙子闭塞, 然后解除 PCI 导管的气球, 并从引导导管取出这个导管。在通缩后立即进行血管造影, 并在 PCI 导管的球囊取出后, 确认患者远端至闭塞部位的灌注, 10 分钟后, 每当心肌缺血的迹象显示为5分钟以上, 并立即重新闭塞的小伙子。</li>
		<li>允许缺血心肌再灌注2小时。以血浆和血清样品为 10, 30, 60 和115分钟的再灌注 (2.1.8 和 2.1.9)。监控 BGA 在60和115分钟 (2.1.10)。</li>
		<li>将 PCI 导管与导丝重新插入与用于缺血的位置完全相同。将 PCI 导管的气球充气, 并通过血管造影 (2.2.3) 确认其闭塞。从左心室取出压力导管, 停止录音。</li>
		<li>注入100毫升2% 埃文斯蓝色磷酸盐缓冲盐水 (PBS, pH 7.4) 进入中心静脉线。大约三十年代以后, 当整个动物变成蓝色, 注射40毫升20% 氯化钾弄死动物。死亡由心电图信号和脉搏波缺乏证实。</li>
	</ol></li>
</ol>3. 取样技术
<ol><li>
心脏的提取、解剖和取样 (图 4)
	<ol>
<li>执行胸骨来暴露心脏。按照 Koudstaal 和同事以前描述的协议, 步骤8-2 和 8-318。切开心包, 同时检查异常, 这可能源于早期心包炎, 并排除动物进一步评估。</li>
		<li>卸除 PCI 和导向导管。消费心脏进一步分析。切开腔静脉, 用吸入泵取出血液, 然后切断所有连接心脏与身体的大血管。</li>
		<li>用室温生理盐水冲洗心脏内外。权衡整颗心。</li>
		<li>在30-40 分钟内, 将心脏切成3-5 毫米左右的切片, 从顶端到腱腱的二尖瓣, 用锋利的刀子垂直于长轴。</li>
		<li>注意始终将心脏放在与腹侧朝向相同的方向上, 以保持剪切样本的方向 (图 5)。</li>
		<li>使用数码单镜头反射相机拍摄心脏切片。</li>
		<li>切断右心室 (不需要丢弃)。照片左心室切片, 并权衡所有切片的总重量的左心室。</li>
		<li>区分埃文斯蓝阳性和埃文斯蓝阴性组织的所有部分。解剖切片, 以分离的缺血性 (埃文斯蓝阴性) 从非缺血性组织 (埃文斯蓝阳性) 使用手术刀。</li>
		<li>首先分析埃文斯蓝阴性部分 (缺血性区域风险, AAR)。把它们都称重, 放入塑料容器中。</li>
		<li>覆盖切片完全与100-150 毫升 (根据心脏大小) 苯基四氮唑氯溶液 (2 克 TTC, 16 克葡聚糖, 分子量 48000-90000, 在200毫升 PBS, 新鲜准备), 使心脏块可以自由移动内的解决方案。盖上容器和孵化20分钟, 在37摄氏度, 而轻轻摇晃。</li>
		<li>在这20分钟的潜伏期体重的埃文斯蓝阳性片 (区域不处于危险中,), 采取组织-植骨标本 (从伤害选择最远端部分) 和存储在-80 °c 进一步分析。将其余部分转移到4% 甲醛溶液中, 在室温下贮存组织学切片。</li>
		<li>从 TTC 解决方案中移除 AAR 部件。红染色组织是可行的缺血性组织 (维生素), 非染色组织为坏死性缺血性组织 (吹毛求疵)。2小块 (2-3 毫米块) 从维生素, 嵌入到组织和存储在-80 °c, 以进一步分析。这些样品应该有相同的重量。</li>
		<li>修复其余的部分 (从 AAR 派生的所有切片), 将其固定在一个泡沫塑料容器中, 并完全覆盖4% 甲醛溶液在室温下在一个通风罩24小时。在接下来的步骤中, 这些片断应该保持平面以供照相文档参考。</li>
		<li>第二天, 照片两侧的作品与一个高分辨率的相机具有相同的变焦设置和距离从组织 (相同的放大)。向所有图片添加自动缩放条。所有条形必须具有相同的长度。 注意: 高分辨率的摄像机应该连接到自动添加缩放条到每张照片的软件。</li>
	</ol>
</li>
	<li>
AAR 和梗死面积的计算
	<ol>
<li>左心室的%AAR = (在 g 中的左心室重量中的 AAR 重量) * 100。</li>
		<li>使用 ImageJ 软件计算的总表面积的 AAR 和吹毛求疵 (两侧的每件) 基于照片。</li>
		<li>通过使用 "角度" 工具中的直线选择刻度线长度来调整缩放条。从菜单中选择 "分析" > "设置比例", 然后插入刻度线的已知距离和单位。选择 "全局", 以便将相同的比例应用于所有图片。</li>
		<li>用自由手选择工具标记组织的整个表面积, 计算 AAR。小心不要包括组织和/或脂肪组织的侧面 (高度) (图 6-C)。</li>
		<li>通过从 "分析" > "设置测量" 菜单中选择 "区域" 和 "显示标签" 来设置测量。测量表面积, 从分析 > 测量。</li>
		<li>重复步骤3.2.5 测量 (只标记未染色的组织)。注: 不包括脂肪组织 (图 6 D) 在吹毛求疵的计算。在组织的另一侧重复步骤。</li>
		<li>计算每块组织的平均 AAR 和吹毛求疵。</li>
		<li>使用从3.2.7 获得的值, 以计算出 aar 的百分比: aar 的%NIT = (在 cm 的2/σ平均表面积在 cm2) * 100。</li>
		<li>两个不同的调查员应该重复上述方法。可接受的差额差值为 < 10%。</li>
	</ol>
</li>
	<li>
缺血标记
	<ol>
<li>使用以前被描述为19的单丛 Luminex 型检测方法, 以-80 摄氏度 (2.1.9) 为测量心肌肌钙蛋白水平的 EDTA 等离子样品。</li>
	</ol>
</li>
</ol>

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H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomy+of+the+pig+heart:+comparisons+with+normal+human+cardiac+structure.">Anatomy of the pig heart: comparisons with normal human cardiac structure.</a> J Anat. 193 (Pt 1), 105-119 (1998).</li><li>Heusch, G., Skyschally, A., Schulz, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+in-situ+pig+heart+with+regional+ischemia/reperfusion+-+ready+for+translation.">The in-situ pig heart with regional ischemia/reperfusion - ready for translation.</a> J Mol Cell Cardiol. 50, 951-963 (2011).</li><li>Poirier, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exercise,+heart+rate+variability,+and+longevity:+the+cocoon+mystery?.">Exercise, heart rate variability, and longevity: the cocoon mystery?.</a> Circulation. , 2085-2087 (2014).</li><li>Milani-Nejad, N., Janssen, P. M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small+and+large+animal+models+in+cardiac+contraction+research:+advantages+and+disadvantages.">Small and large animal models in cardiac contraction research: advantages and disadvantages.</a> Pharmacol Ther. 141, 235-249 (2014).</li><li>Bloor, C. M., White, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+development+of+the+coronary+collateral+circulation+during+coronary+artery+occlusion+in+the+conscious+dog.">Functional development of the coronary collateral circulation during coronary artery occlusion in the conscious dog.</a> Am J Pathol. 67, 483-500 (1972).</li><li>Banz, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Locally+targeted+cytoprotection+with+dextran+sulfate+attenuates+experimental+porcine+myocardial+ischaemia/reperfusion+injury.">Locally targeted cytoprotection with dextran sulfate attenuates experimental porcine myocardial ischaemia/reperfusion injury.</a> Eur Heart J. 26, 2334-2343 (2005).</li><li>Krombach, G. A., Kinzel, S., Mahnken, A. H., G&#252;nther, R. W., Buecker, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Minimally+Invasive+Close-Chest+Method+for+Creating+Reperfused+or+Occlusive+Myocardial+Infarction+in+Swine.">Minimally Invasive Close-Chest Method for Creating Reperfused or Occlusive Myocardial Infarction in Swine.</a> Invest Radiol. 40, 14 (2005).</li><li>Suzuki, Y., Lyons, J. K., Yeung, A. C., Ikeno, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+porcine+model+of+reperfused+myocardial+infarction:+in+situ+double+staining+to+measure+precise+infarct+area/area+at+risk.">In vivo porcine model of reperfused myocardial infarction: in situ double staining to measure precise infarct area/area at risk.</a> Catheter Cardiovasc Interv. 71, 100-107 (2008).</li><li>McCall, F. C., 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=Myocardial+infarction+and+intramyocardial+injection+models+in+swine.">Myocardial infarction and intramyocardial injection models in swine.</a> Nat Protoc. 7, 1479-1496 (2012).</li><li>Koudstaal, S., 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=Myocardial+infarction+and+functional+outcome+assessment+in+pigs.">Myocardial infarction and functional outcome assessment in pigs.</a> J Vis Exp. , e51269 (2014).</li><li>Kamat, P., 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=Dexrazoxane+Shows+No+Protective+Effect+in+the+Acute+Phase+of+Reperfusion+during+Myocardial+Infarction+in+Pigs.">Dexrazoxane Shows No Protective Effect in the Acute Phase of Reperfusion during Myocardial Infarction in Pigs.</a> PLoS One. 11, e0168541 (2016).</li><li>Carden, D. L., Granger, D. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathophysiology+of+ischaemia-reperfusion+injury.">Pathophysiology of ischaemia-reperfusion injury.</a> J Pathol. 190, 255-266 (2000).</li><li>P&#233;rez de Prado, A., 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=Closed-chest+experimental+porcine+model+of+acute+myocardial+infarction-reperfusion.">Closed-chest experimental porcine model of acute myocardial infarction-reperfusion.</a> J Pharmacol Toxicol Methods. 60, 301-306 (2009).</li><li>Lown, B., Levine, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+carotid+sinus.+Clinical+value+of+its+stimulation.">The carotid sinus. Clinical value of its stimulation.</a> Circulation. 23, 766-789 (1961).</li><li>Regueiro-Purri&#241;os, M., 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=Ventricular+Arrhythmias+and+Mortality+Associated+with+Isoflurane+and+Sevoflurane+in+a+Porcine+Model+of+Myocardial+Infarction.">Ventricular Arrhythmias and Mortality Associated with Isoflurane and Sevoflurane in a Porcine Model of Myocardial Infarction.</a> J Am Assoc Lab Anim Sci. , (2011).</li><li>Roberts, L. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evans+blue+toxicity.">Evans blue toxicity.</a> Can Med Assoc J. 71, 489-491 (1954).</li><li>Ellenbroek, G. H. J. M., 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=Primary+Outcome+Assessment+in+a+Pig+Model+of+Acute+Myocardial+Infarction.">Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction.</a> J Vis Exp. , e54021 (2016).</li></ol>

作者声明没有利益冲突。

心肌 I. 型损伤对急性心肌梗死后的最终梗死大小有显著影响, 直接转化为患者的预后3。了解心肌 I./R 损伤的病理生理学是减少或预防其发生的第一步。心肌 I./R 损伤是闭塞血管再灌注后直接发生的急性疾病。I/R 损伤导致活化的先天免疫应答和细胞损伤发生在现场的再灌注和周围组织20。最近的一项研究表明, FXIIa 抑制剂8治疗大鼠脑 I/R 损伤模?...

缺血性心脏病, 特别是急性心肌梗死 (MI), 是发达国家死亡的主要原因1。今天, 标准治疗 MI 是经皮冠状动脉介入 (PCI), 气囊导管治疗。影响 PCI 治疗急性心肌梗死患者生活质量和预后的关键因素之一是梗塞面积。大小的减少可能对患者生存和预后有很大的影响2。心肌缺血/再灌注 (I.) 损伤对梗死大小有显著影响, 因此心血管研究的主要目的之一是预防或减少心肌 I./r 损伤3。我/R 损伤的确切机制仍在调查中4。激活血浆叶栅和内皮细胞是 I/R 损伤的标志5。凝血系统的激活明显涉及6、7。最近, FXII 的作用, 作为一个早期的上游肽参与凝血叶的接触相活化, 已显示在 FXII 敲出大鼠脑 I/R 损伤模型8。在猪模型中验证这些结果是临床翻译的重要一步。因此, 我们正在试验一种新的笼 (80 kDa 蛋白酶) FXIIa 抑制剂的背景下心肌 I/R 损伤的试验研究。
动物模型, 模仿急性 MI 和 PCI 治疗的临床情况, 是必要的, 以提高我们对心肌 I./R 损伤的病理生理学的认识, 并测试新的治疗方案。猪是临床心肌 I. 型损伤的良好动物模型。这不仅是因为他们的心脏是非常相似的人的心脏解剖和冠状动脉循环, 但他们也显示类似的病理生理反应心肌缺血和再灌注9,10。其他模型, 如老鼠和老鼠不满足这些标准, 并显示相当大的差异时, 与人的心脏11,12, 而狗例如, 有更多的抵押品冠状动脉血管相比, 人类13。
猪急性心肌梗死模型已广泛应用于心血管研究, 包括心肌 I./R 损伤14,15,16,17。后者是一种炎症状态, 因为它减少了与胸骨或开胸手术有关的炎症反应是必不可少的。采用临床 C 臂血管造影设置的闭合胸模型克服了这一问题。此外, 最重要的一点是, 我们的议定书提供了一个准确的区分缺血性 (危险区域, AAR) 和左心室的非缺血性区域 (没有危险的地区), 以便梗塞大小 (坏死缺血性组织, 吹毛求疵) 可以被准确地确定。本论文的目的是明确界定猪心肌 I./r 损伤模型的可再生方法, 特别是在心肌组织取样方面, 这将有助于更精确地分析 I. r 损伤的分子机制和更清楚地了解新药物治疗的效果。

<table><tbody><tr><td>ABL 90 Flex, blood gas analyser</td><td>Radiometer</td><td>-</td><td>Blood gas analysis (BGA)</td></tr><tr><td>ACT Plus</td><td>Medtronic</td><td>-</td><td>Activated clotting time</td></tr><tr><td>Atropin</td><td>Sintetica</td><td>-</td><td>Atropinum Sulfas, 0,5mg/ml</td></tr><tr><td>Balance (20-500 Kg)</td><td>NAGATA Scale, Tiwan</td><td>HTB/HTR</td><td>Alternative products can be used</td></tr><tr><td>Balance (21-4200 g)</td><td>Mettler toledo, Switzerland</td><td>MS4002SDR</td><td>Alternative products can be used</td></tr><tr><td>Blood collection tubes: EDTA, citrate and serum</td><td>S-Monovette, Nuembrecht, Germany</td><td>05.1167.001,&lt;br/&gt; 05.1071.001&lt;br/&gt; and&lt;br/&gt; 05.1557.001 respectively</td><td>Alternative products can be used</td></tr><tr><td>BV Pulsera mobile C-arm</td><td>Philips</td><td>-</td><td>Alternative products can be used</td></tr><tr><td>Centrifuge</td><td>Labcare, UK</td><td>ALC PK120R</td><td>Alternative products can be used</td></tr><tr><td>Defibrillator Lifepak 12</td><td>Medtronic</td><td>-</td><td>Alternative products can be used</td></tr><tr><td>Dextran from Leuconostoc mesenteroides</td><td>Sigma-Aldrich, Germany</td><td>D3759</td><td>Average M.wt 48000-90000</td></tr><tr><td>Digital single lens reflex camera</td><td>Sony, Thailand</td><td>DSLR-A500/A550</td><td>Alternative products can be used</td></tr><tr><td>Dissecting forceps</td><td></td><td></td><td>Alternative products can be used</td></tr><tr><td>EMPIRA RX PCI dilatation catheter</td><td>Cordis, Johnson&amp;amp;Johnson, USA</td><td>85R15300S</td><td>Diameter 3 mm, length 15 mm, Alternative products can be used</td></tr><tr><td>EMPIRA RX PCI dilatation catheter</td><td>Cordis, Johnson&amp;amp;Johnson, USA</td><td>85R15350S</td><td>Diameter 3.5 mm, length 15 mm, Alternative products can be used</td></tr><tr><td>Evans Blue</td><td>Sigma-Aldrich, Germany</td><td>E2129</td><td>Toxic</td></tr><tr><td>Fabius GS premium respirator</td><td>Dr&amp;auml;ger, L&amp;uuml;beck, Germany</td><td>-</td><td>Anesthesia work station, Alternative products can be used</td></tr><tr><td>Fentanyl</td><td>Inselspital ISPI</td><td>-</td><td>Fentanyl 2500mcg/50ml</td></tr><tr><td>Formaldehyde</td><td>Pathology Institute, Bern University</td><td>SI148701</td><td>Alternative products can be used</td></tr><tr><td>FXIIa inhibitor</td><td>Provided by Prof. Christian Heinis&#039; laboratory in EPFL</td><td></td><td>Novel bicyclic peptide</td></tr><tr><td>Galeo, coronary guidewire</td><td>Biotronik, Germany</td><td>125497</td><td>Alternative products can be used</td></tr><tr><td>Guidance catheter</td><td>Boston Scientific, Florida, USA</td><td>34356-06</td><td>6F (100 cm, EB3.75). Alternative products can be used</td></tr><tr><td>Heparin Sodium</td><td>Drossapharm, Basel, Switzerland</td><td>-</td><td>Liquemin, 25000 U.I./5 ml</td></tr><tr><td>High end electrosurgery</td><td>BOWA, Germany</td><td>ARC 400</td><td>Electrical source for blood suction. Alternative products can be used</td></tr><tr><td>Hydro-Guardmini breathing filter</td><td>Intersurgical, Lithuania</td><td>1745000</td><td>Filters</td></tr><tr><td>Image J</td><td>National Institute of Health, USA</td><td>1.47v</td><td>Alternative products can be used</td></tr><tr><td>Inflation device, Atrion QL2530</td><td>Atrion medical product, Alabama, USA</td><td>96402</td><td>Alternative products can be used</td></tr><tr><td>IntelliVue MP 70</td><td>Philips, Boeblingen, Germany</td><td>-</td><td>Monitor (ECG, heart rate, blood presure and body temperature). Alternative products can be used</td></tr><tr><td>KCl</td><td>Sintetica SA</td><td>-</td><td>Potassium chloride 15%</td></tr><tr><td>Ketamine</td><td>Vetoquinol</td><td>-</td><td>Narketan, 1ml/100mg</td></tr><tr><td>LR-ACT</td><td>Medtronic</td><td>402-01</td><td>ACT special syringes</td></tr><tr><td>Midazolam</td><td>Roche</td><td>-</td><td>Dormicum, 5mg/ml</td></tr><tr><td>Monopolar scalpel</td><td></td><td></td><td>Alternative products can be used</td></tr><tr><td>Needle holder</td><td></td><td></td><td>Alternative products can be used</td></tr><tr><td>High resolution camera, PathStand Macro Imaging Stand for Grossing</td><td>Spotimaging, USA</td><td></td><td>1080 p HD resolution. Alternative products can be used</td></tr><tr><td>PBS</td><td>In-house preparation</td><td>-</td><td>Alternative products can be used</td></tr><tr><td>Peripheral venous cannula, 18 G</td><td></td><td></td><td>Alternative products can be used</td></tr><tr><td>PowerLab 4/35 data acquisition system</td><td>Adinstruments, Spechbach, Germany</td><td>-</td><td></td></tr><tr><td>Rotamax120T</td><td>Heidolph, Germany</td><td>544-41200-00</td><td>Shaker. Alternative can be used</td></tr><tr><td>R&amp;uuml;schelit-Super Safety Clear Tube</td><td>Teleflex, Dublin, Irland</td><td>112480</td><td>Air way tubing, Alternative products can be used</td></tr><tr><td>Safe Pico Aspirator Syringes</td><td>Radiometer</td><td>956-622</td><td>BGA special syringes</td></tr><tr><td>Saline</td><td>Sintetica Bioren</td><td>-</td><td>NaCl 0,9%. Alternative products can be used</td></tr><tr><td>Sevorane 1.5%</td><td>AbbVie AG</td><td>-</td><td>Sevorane 250ml 100%</td></tr><tr><td>Sheath</td><td>Cordis, Johnson&amp;amp;Johnson, USA</td><td>504-607 A</td><td>AVANTI + / 7 F, Alternative products can be used</td></tr><tr><td>Space infusion pump</td><td>B.Braun Medical AG, Germany</td><td>-</td><td>For infusion of fentanyl. Alternative products can be used</td></tr><tr><td>SPR-350 (Millar catheter)</td><td>Adinstruments, Texas, USA</td><td>840-8166</td><td>MIKRO-TIP, 5F, 120 cm</td></tr><tr><td>Sternotomy saw</td><td></td><td></td><td>Alternative products can be used</td></tr><tr><td>Sutures</td><td>ETHICON, Johnson&amp;amp;Johnson, USA</td><td>Y3110H</td><td>Monocryl 3-0 SH-1 Plus. Alternative products can be used</td></tr><tr><td>Syringes (20, 10 and 5 mL)</td><td>CODAN,Baar, Switzerland</td><td>62.7602,&lt;br/&gt; 62.6616,&lt;br/&gt; 62.5607&lt;br/&gt; respectively</td><td>Used to inject anesthetic materials intramuscularly or directly into the central venous line. Also to inject heparin or FXIIa or the respective control. Alternative products can be used</td></tr><tr><td>Thorax spreader</td><td></td><td></td><td>Alternative products can be used</td></tr><tr><td>Tissue-tek</td><td>SAKURA, Netherlands</td><td>4583</td><td>O.C.T. compound</td></tr><tr><td>Vascular forceps</td><td></td><td></td><td>Alternative products can be used</td></tr><tr><td>Xenetix 300 contrast media</td><td>Guerbet, Z&amp;uuml;rich, Switzerland</td><td>-</td><td>Lobitridol, 300 mg iodide/ml</td></tr><tr><td>Xylazine</td><td>Vetoquinol</td><td>-</td><td>Xylapan, 20mg/1 mL</td></tr><tr><td>2,3,5-Triphenyltetrazolium choride</td><td>Sigma-Aldrich, Austria</td><td>T8877</td><td></td></tr><tr><td>500 &amp;mu;L tubes (eppendorf)</td><td>Trefflab, Switzerland</td><td>96.08185.9.03</td><td>Alternative products can be used</td></tr></tbody></table>

improvement of a closed chest porcine myocardial infarction model by standardization of tissue and blood sampling procedures

心肌缺血再灌注 (一/R) 损伤对心肌梗死后坏死区的近半数有贡献。到目前为止还没有批准的药物来预防或减少心肌的 I/R 损伤。研究和理解心肌损伤的病理生理机制是发展成功治疗的必要条件。大型动物实验是翻译方法的重要步骤。猪急性心肌梗死模型由我们自己和其他人自行建立和描述。我们的目标是进一步提高模型的价值, 重点放在取样技术, 用于未来的实验。此外, 我们强调小但重要的步骤, 可能影响最终结果的质量。为模拟心肌 I./R 损伤的临床情况, 经皮冠状动脉介入治疗 (PCI) 导管插入麻醉猪左前降冠状动脉 (童子)。°°°This 模型模仿急性心肌梗死和 PCI 治疗的人, 有可能准确地确定的区域在危险, 以及坏死和可行的缺血性组织。该模型用于研究 FXIIa 笼肽抑制剂的作用。该模型也可以修改, 以允许更长的再灌注时间, 以研究晚期心肌梗死的影响。

一动物在 FXIIa 抑制剂或控制肽的管理之前过早地死了由于技术错误 (血压突然下落在缺血时间, 在测试物质的加法之前)。一只动物被排除在 FXIIa 抑制剂组, 因为没有观察到缺血/再灌注损伤由于左前降动脉的异常解剖 (小伙子)。左心室的很大一部分, 包括先端, 由该动物的扬抑动脉灌注。最后分析的动物是 n = 2 在笼 FXIIa 肽抑制剂小组 (平均重量 27.5 2.5 公斤) 和 n = 3 接受不活...

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Improvement of a Closed Chest Porcine Myocardial Infarction Model by Standardization of Tissue and Blood Sampling Procedures

在这里, 我们演示了一个标准化的方法, 以规范建立猪急性心肌梗塞模型的抽样程序, 以提高其平移值, 了解心肌缺血/再灌注损伤的病理生理学并测试新的药物候选者。

组织和采血程序标准化改善闭合性胸猪心肌梗死模型的研究

Myocardial ischemia reperfusion (I/R) injury contributes to almost half of the necrotic area after myocardial infarction. To date there is no approved ...

improvement-closed-chest-porcine-myocardial-infarction-model

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10.8K 次观看.  University of Bern. 在这里, 我们演示了一个标准化的方法, 以规范建立猪急性心肌梗塞模型的抽样程序, 以提高其平移值, 了解心肌缺血/再灌注损伤的病理生理学并测试新的药物候选者。

视频: Improvement of a Closed Chest Porcine Myocardial Infarction Model by Standardization of Tissue and Blood Sampling Procedures

A Murine Closed-chest Model of Myocardial Ischemia and Reperfusion

Surgical trauma by thoracotomy in open-chest models of coronary ligation induces an immune response which modifies different mechanisms involved in ischemia and reperfusion. Immune response includes cytokine expression and release or secretion of endogenous ligands of innate immune receptors. Activation of innate immunity can potentially modulate infarct size. We have modified an existing murine closed-chest model using hanging weights which could be useful for studying myocardial pre- and postconditioning and the role of innate immunity in myocardial ischemia and reperfusion. This model allows animals to recover from surgical trauma before onset of myocardial ischemia.
Volatile anesthetics have been intensely studied and their preconditioning effect for the ischemic heart is well known. However, this protective effect precludes its use in open chest models of coronary artery ligation. Thus, another advantage could be the use of the well controllable volatile anesthetics for instrumentation in a chronic closed-chest model, since their preconditioning effect lasts up to 72 hours. Chronic heart diseases with intermittent ischemia and multiple hit models are other possible applications of this model.
For the chronic closed-chest model, intubated and ventilated mice undergo a lateral blunt thoracotomy via the 4th intercostal space. Following identification of the left anterior descending a ligature is passed underneath the vessel and both suture ends are threaded through an occluder. Then, both suture ends are passed through the chest wall, knotted to form a loop and left in the subcutaneous tissue. After chest closure and recovery for 5 days, mice are anesthetized again, chest skin is reopened and hanging weights are hooked up to the loop under ECG control.
At the end of the ischemia/reperfusion protocol, hearts can be stained with TTC for infarct size assessment or undergo perfusion fixation to allow morphometric studies in addition to histology and immunohistochemistry.

Surgical trauma induces an inflammatory response. Cytokines and endogenous ligands are known to modulate myocardial infarct size following ischemia and reperfusion. We present a modified closed-chest model of murine ischemia and reperfusion using hanging weights to minimize effects of thoracotomy.

闭胸鼠心肌缺血再灌注模型

Surgical trauma by thoracotomy in open-chest models of coronary ligation induces an immune response which modifies different mechanisms involved in ...

科研

医学

Myocardial Infarction and Functional Outcome Assessment in Pigs

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One important prerequisite is a good understanding of all safety and efficacy aspects obtained in a large animal model that validly reflect the human scenario of myocardial infarction (MI). Pigs are widely used in this regard since their cardiac size, hemodynamics, and coronary anatomy are close to that of humans. Here, we present an effective protocol for using the porcine MI model using a closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. This approach is based on 90 min of myocardial ischemia, inducing large left ventricle infarction of the anterior, septal and inferoseptal walls. Furthermore, we present protocols for various measures of outcome that provide a wide range of information on the heart, such as cardiac systolic and diastolic function, hemodynamics, coronary flow velocity, microvascular resistance, and infarct size. This protocol can be easily tailored to meet study specific requirements for the validation of novel cardioregenerative biologics at different stages (i.e. directly after the acute ischemic insult, in the subacute setting or even in the chronic MI once scar formation has been completed). This model therefore provides a useful translational tool to study MI, subsequent adverse remodeling, and the potential of novel cardioregenerative agents.

This protocol describes the porcine myocardial infarction (MI) model using a 90 min closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. Furthermore, the protocol for several outcome parameters, such as cardiac function, hemodynamics, microvascular resistance, and infarct size, are also presented.

心肌梗死和功能预后评估的猪

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One ...

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 ...

3D Whole-heart Myocardial Tissue Analysis

Cardiac regenerative therapies aim to protect and repair the injured heart in patients with ischemic heart disease. By injecting stem cells or other biologicals that enhance angio- or vasculogenesis into the infarct border zone (IBZ), tissue perfusion is improved, and the myocardium can be protected from further damage. For maximum therapeutic effect, it is hypothesized that the regenerative substance is best delivered to the IBZ. This requires accurate injections and has led to the development of new injection techniques. To validate these new techniques, we have designed a validation protocol based on myocardial tissue analysis. This protocol includes whole-heart myocardial tissue processing that enables detailed two-dimensional (2D) and three-dimensional (3D) analysis of the cardiac anatomy and intramyocardial injections. In a pig, myocardial infarction was created by a 90-min occlusion of the left anterior descending coronary artery. Four weeks later, a mixture of a hydrogel with superparamagnetic iron oxide particles (SPIOs) and fluorescent beads was injected in the IBZ using a minimally-invasive endocardial approach. 1 h after the injection procedure, the pig was euthanized, and the heart was excised and embedded in agarose (agar). After the solidification of the agar, magnetic resonance imaging (MRI), slicing of the heart, and fluorescence imaging were performed. After image post-processing, 3D analysis was performed to assess the IBZ targeting accuracy. This protocol provides a structured and reproducible method for the assessment of the targeting accuracy of intramyocardial injections into the IBZ. The protocol can be easily used when the processing of scar tissue and/or validation of the injection accuracy of the whole heart is desired.

This protocol describes a novel method for the 3D comparison of whole-heart myocardial tissue with MRI. This is designed for the accurate assessment of intramyocardial injections in the infarct border zone of a chronic porcine model of myocardial infarction.

3D全心脏心肌组织分析

Cardiac regenerative therapies aim to protect and repair the injured heart in patients with ischemic heart disease. By injecting stem cells or other ...

Establishing a Swine Model of Post-myocardial Infarction Heart Failure for Stem Cell Treatment

Although advances have been achieved in the treatment of heart failure (HF) following myocardial infarction (MI), HF following MI remains one of the major causes of mortality and morbidity around the world. Cell-based therapies for cardiac repair and improvement of left ventricular function after MI have attracted considerable attention. Accordingly, the safety and efficacy of these cell transplantations should be tested in a preclinical large animal model of HF prior to clinical use. Pigs are widely used for cardiovascular disease research due to their similarity to humans in terms of heart size and coronary anatomy. Therefore, we sought to present an effective protocol for the establishment of a porcine chronic HF model using closed-chest coronary balloon occlusion of the left circumflex artery (LCX), followed by rapid ventricular pacing induced with pacemaker implantation. Eight weeks later, the stem cells were administered by intramyocardial injection in the peri-infarct area. Then the infarct size, cell survival, and left ventricular function (including echocardiography, hemodynamic parameters, and electrophysiology) were evaluated. This study helps establish a stable preclinical large animal HF model for stem cell treatment.

We sought to establish a swine model of heart failure induced by left circumflex artery blockage and rapid pacing to test the effect and safety of intramyocardial administration of stem cells for cell-based therapies.

建立干细胞治疗心肌梗塞心力衰竭的猪模型

Although advances have been achieved in the treatment of heart failure (HF) following myocardial infarction (MI), HF following MI remains one of the major ...

Tissue Preparation Techniques for Contrast-Enhanced Micro Computed Tomography Imaging of Large Mammalian Cardiac Models with Chronic Disease

Structural remodeling is a common consequence of chronic pathological stresses imposed on the heart. Understanding the architectural and compositional properties of diseased tissue is critical to determine their interactions with arrhythmic behavior. Microscale tissue remodeling, below the clinical resolution, is emerging as an important source of lethal arrhythmia, with high prevalence in young adults. Challenges remain in obtaining high imaging contrast at sufficient microscale resolution for preclinical models, such as large mammalian whole hearts. Moreover, tissue composition-selective contrast enhancement for three-dimensional high-resolution imaging is still lacking. Non-destructive imaging using micro-computed tomography shows promise for high-resolution imaging. The objective was to alleviate sufferance from X-ray over attenuation in large biological samples. Hearts were extracted from healthy pigs (N = 2), and sheep (N = 2) with either induced chronic myocardial infarction and fibrotic scar formation or induced chronic atrial fibrillation. Excised hearts were perfused with: a saline solution supplemented with a calcium ion quenching agent and a vasodilator, ethanol in serial dehydration, and hexamethyldisilizane under vacuum. The latter reinforced the heart structure during air-drying for 1 week. Collagen-dominant tissue was selectively bound by an X-ray contrast-enhancing agent, phosphomolybdic acid. Tissue conformation was stable in air, permitting long-duration microcomputed tomography acquisitions to obtain high-resolution (isotropic 20.7 &#181;m) images. Optimal contrast agent loading by diffusion showed selective contrast enhancement of the epithelial layer and sub-endocardial Purkinje fibers in healthy pig ventricles. Atrial fibrillation (AF) hearts showed enhanced contrast accumulation in the posterior walls and appendages of the atria, attributed to greater collagen content. Myocardial infarction hearts showed increased contrast selectively in regions of cardiac fibrosis, which enabled the identification of interweaving surviving myocardial muscle fibers. Contrast-enhanced air-dried tissue preparations enabled microscale imaging of the intact large mammalian heart and selective contrast enhancement of underlying disease constituents.

Here, we present a protocol to obtain high resolution micro computed tomography images of healthy and pathological large mammalian whole hearts with collagen-selective contrast enhancement.

用于慢性病大型哺乳动物心脏模型对比增强显影显微计算机断层扫描的组织制备技术

Structural remodeling is a common consequence of chronic pathological stresses imposed on the heart. Understanding the architectural and compositional ...

Myocardial Infarction by Percutaneous Embolization Coil Deployment in a Swine Model

Myocardial infarction (MI) is the leading cause of mortality worldwide. Despite the use of evidence-based treatments, including coronary revascularization and cardiovascular drugs, a significant proportion of patients develop pathological left-ventricular remodeling and progressive heart failure following MI. Therefore, new therapeutic options, such as cellular and gene therapies, among others, have been developed to repair and regenerate injured myocardium. In this context, animal models of MI are crucial in exploring the safety and efficacy of these experimental therapies before clinical translation. Large animal models such as swine are preferred over smaller ones due to the high similarity of swine and human hearts in terms of coronary artery anatomy, cardiac kinetics, and the post-MI healing process. Here, we aimed to describe an MI model in pig by permanent coil deployment. Briefly, it comprises a percutaneous selective coronary artery cannulation through retrograde femoral access. Following coronary angiography, the coil is deployed at the target branch under fluoroscopic guidance. Finally, complete occlusion is confirmed by repeated coronary angiography. This approach is feasible, highly reproducible, and emulates the pathogenesis of human non-revascularized MI, avoiding the traditional open-chest surgery and the subsequent postoperative inflammation. Depending on the time of follow-up, the technique is suitable for acute, sub-acute, or chronic MI models.

Myocardial infarction (MI) animal models that emulate the natural process of the disease in humans are crucial to understanding pathophysiological mechanisms and testing the safety and efficacy of new emergent therapies. Here, we describe an MI swine model created by deploying a percutaneous embolization coil.

猪模型中经皮栓塞线圈部署的心肌梗死

Myocardial infarction (MI) is the leading cause of mortality worldwide. Despite the use of evidence-based treatments, including coronary revascularization ...

Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury

Myocardial ischemia and reperfusion injury (MIRI), induced by coronary heart disease (CHD), causes damage to the cardiomyocytes. Furthermore, evidence suggests that thrombolytic therapy or primary percutaneous coronary intervention (PPCI) does not prevent reperfusion injury. There is still no ideal animal model for MIRI. This study aims to improve the MIRI model in rats to make surgery easier and more feasible. A unique method for establishing MIRI is developed by using a soft tube during a key step of the ischemic period. To explore this method, thirty rats were randomly divided into three groups: sham group (n = 10); experimental model group (n = 10); and existing model group (n = 10). Findings of triphenyltetrazolium chloride staining, electrocardiography, and percent survival are compared to determine the accuracies and survival rates of the operations. Based on the study results, it has been concluded that the improved surgery method is associated with a higher survival rate, elevated ST-T segment, and larger infarct size, which is expected to mimic the pathology of MIRI better.

Myocardial ischemia-reperfusion model of rat heart is improved by using a self-made retractor, polyvinyl chloride tube, and a unique knotting method. Electrocardiogram, triphenyltetrazolium chloride and histological staining, and percent survival analysis results showed that the improved model group has higher success and survival rates than the already existing model group.

心肌缺血再灌注损伤的改进啮齿动物模型

Myocardial ischemia and reperfusion injury (MIRI), induced by coronary heart disease (CHD), causes damage to the cardiomyocytes. Furthermore, evidence ...

Dissection Techniques and Histological Sampling of the Heart in Large Animal Models for Cardiovascular Diseases

The standard gross examination and sampling are key elements in the reproducibility and success of experimental studies of cardiovascular diseases carried out in large animals. Considering the complex anatomy of the heart, interspecies differences, and the types of compensatory and pathological reactions, consistent protocols are challenging to implement. The utilization of multiple dissection protocols is usually adapted to suit the prosector's experience, and personal preference continues to be a source of experimental and interobserver variability. Here, the aim is to present the main anatomical features and landmarks, dissection protocols, and histological sampling standards of the heart in some commonly used species (including dogs, pigs, ruminants, and cats) as models of cardiovascular diseases.
Two standard gross examination protocols are presented here. First, the inflow-outflow method, which follows the physiological blood flow direction through the heart and large vessels (frequently used in dogs, ruminants, and pigs), and second, the four-chamber dissection technique (exemplified in cats). Both techniques can be adapted to any species in certain experimental circumstances. The sampling protocols include all the areas of interest (sinoatrial node, ventricles, interventricular septum, atria, valves, and aorta), and if properly carried out, improve both the reproducibility and reliability of experimental studies.

Due to the complex anatomy, a consistently reproducible dissection and harvesting protocol for cardiac samples can be challenging to implement. This manuscript presents the key elements of some standard cardiac dissection protocols, highlighting both the gross examination approaches and the sampling sites commonly used for histopathologic examination.

心血管疾病大型动物模型中心脏的解剖技术和组织学取样

The standard gross examination and sampling are key elements in the reproducibility and success of experimental studies of cardiovascular diseases carried ...

Large-Animal Model of Donation after Circulatory Death and Normothermic Regional Perfusion for Cardiac Assessment

The increase in demand for cardiac transplantation throughout the years has fueled interest in donation after circulatory death (DCD) to expand the organ donor pool. However, the DCD process is associated with the risk of cardiac tissue injury due to the inevitable period of warm ischemia. Normothermic regional perfusion (NRP) allows for an in situ organ assessment, allowing the procurement of hearts determined to be viable. Here, we describe a clinically relevant large-animal model of DCD followed by NRP. Circulatory death is established in anesthetized pigs by stopping mechanical ventilation. After a preset warm ischemia period, an extracorporeal membrane oxygenator (ECMO) is used for a NRP period lasting at least 30 min. During this reperfusion period, the model allows the collection of various myocardial biopsies and blood samples for initial cardiac evaluation. Once NRP is weaned, biochemical, hemodynamic, and echocardiographic assessments of cardiac function and metabolism can be performed before organ procurement. This protocol closely simulates the clinical scenario previously described for DCD and NRP in heart transplantation and has the potential to facilitate studies aimed at decreasing ischemia-reperfusion injury and enhance cardiac functional preservation and recovery.

The protocol describes a large-animal (porcine) model of donation after circulatory death, followed by thoracoabdominal normothermic regional perfusion that closely simulates the clinical scenario in heart transplantation, and has the potential to facilitate therapeutic studies and strategies.

用于心脏评估的循环死亡后捐献和正常区域灌注的大型动物模型

The increase in demand for cardiac transplantation throughout the years has fueled interest in donation after circulatory death (DCD) to expand the organ ...