This work has been supported by NIH HL-1034.

约翰·霍普金斯大学动物护理和使用委员会批准的所有动物的协议。 1.设备复合体系建立起来，准备测量的PV曲线示于图1。 <ol><li>体积测量: <ol><li>通过使用注射泵用开关，其允许用户在到达压力极限后，迅速扭转泵产生膨胀和收缩的恒定速率。鼠标PV曲线，使用非常抹了油5毫升玻璃注射器与初始体积（前通胀）设置3毫升空气。 3毫升足够大，在几乎所有的鼠标PV曲线来衡量卷。 </li><li>测量由泵输送通过附加的线性差动变压器到泵壳体，具有一小的传感器杆连接到所述移动针筒柱塞的体积。 注意:实证手段来校正在系统中气体压缩光伏立方米下被描述RVE记录部分。 </li></ol></li><li>压力测量: <ol><li>使用标准的廉价的压力表，射程0-60厘米H 2 O（0-1 PSI）。 </li></ol></li><li>记录测量: <ol><li>为了记录PV曲线使用任何数字录音机XY能力（ 如 PowerLab系统）。设置一个信道来记录修正量信号和另一信道来记录跨肺压（PTP），以图表的PV曲线。使用一个桥前置放大器连接到主PowerLab系统来测量压力。 0-40厘米水柱2 O校准压力通道，并从0-3毫升校准音量通道。 </li></ol></li></ol> 2.修正了天然气压缩注意:这是在一个关键的初始步骤中的设置，因为随着压力的增加，气体体积减小，并且空气递送到小鼠的这样的体积会比SYR的位移越来越少英格桶。 <ol><li>关闭将光伏系统连接到肺部的活塞，因此没有气体能离开系统。开始输注，并观察是否刻录机上的校正量的信道表示任何可测量的变化，因为压力增加至约40cm 的 H 2 O.如果是这样，那么正确的，因为在接下来的步骤。 <ol><li>正确的气体压缩经验从活塞位移测量减去（ 即未修正量）比例通胀压力的一个术语。做一个PowerLab系统的信道（被称为维生素C），这显示数量减去信号系数倍的压力。 </li><li>确定公式中的系数。首先，初步猜测，打开图表记录，并启动泵。由于通胀油管是密封的，调整压力系数倍增，使Vc的通道读取零0-40厘米H 2 O.压力上升如果这样下去，向上或向下，只需调整校正系数，直到横盘在这个压力范围内。这种校正因子将始终是相同的，如果同一3毫升开始在注射器容量不改变。 </li></ol></li></ol>小鼠3实验测试<ol><li>程序小鼠PV曲线的测量结果。所有的动物协议批准了约翰·霍普金斯大学动物护理和使用委员会。 <ol><li>麻醉小鼠（C57BL / 6小鼠在6-12周龄）用氯胺酮（90毫克/千克）和赛拉嗪（15毫克/千克），并由于没有反射运动的确认麻醉。 注意:PV曲线可以在麻醉的小鼠中完成，在不到10分钟，是一个终端程序。 </li><li> Tracheostomize小鼠与18G的存根针管。通过一个小切口，在皮肤上的气管，定位气管，然后做一个小切口，在气管，可插入存根针的地方做到这一点。用线扎固定套管。 </li><li>让老鼠呼吸100％的氧气，至少4分钟。这可以是通过自主呼吸从袋中，或用换气名义上设定为0.2ml，在150次呼吸/分钟的潮气量。 </li><li>关闭气管插管，并允许3-4分钟为鼠标吸收所有的氧气。此氧气吸收过程引起的动物，并在肺11的几乎完整的脱气的死亡。通过测量与心电图电极或直接观察心跳停止确认的小鼠死亡。 </li><li>一旦肺的脱气完成并且肺容积为零时，开始充气与室内空气在所述注射器泵的肺以3毫升/分钟的速率。显示器上的数字记录的压力轨迹，并且当它到达35厘米H 2 O，反向泵浦。 </li><li>按照通缩的曲线，直到压力达到负10厘米H 2 O，而此时的气道已经崩溃，捕捉空气中的肺泡防止进一步的减排量。马上倒T他再次泵，使肺reinflate的崩溃航空公司公开赛。这种异构开放是嘈杂看通胀肢体这个第二通货膨胀的初始部分通常明显。 </li><li>当压力再次达到35厘米H 2 O，反转泵方向，并持续到2日通货紧缩肢体达到0厘米H 2 O.放气肺然后停泵。 </li><li>查看的压力和流量，并在PV曲线的PowerLab图表记录。然后分析PV曲线来检测在肺实质不同的肺病理学发生表型的改变。 </li></ol></li></ol>

<ol>
	<li>Neergaard, K. v. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neue+Auffasungen+&#252;ber+einn+Grundbergriff+der+Atemtechnik.+Die+Retraktionskraft+der+unge,+abhangig+von+den+Oberflachenspannung+in+den+Alveolen.+(New+interpretations+of+basic+concepts+of+respiratory+mechanics.+Correlation+of+pulmonary+recoil+force+with+surface+tension+in+the+alveoli.).">Neue Auffasungen &#252;ber einn Grundbergriff der Atemtechnik. Die Retraktionskraft der unge, abhangig von den Oberflachenspannung in den Alveolen. (New interpretations of basic concepts of respiratory mechanics. Correlation of pulmonary recoil force with surface tension in the alveoli.).</a> Zeitschrift Fur Gesamte Experi Medizin. 66, 373-394 (1929).</li><li>Hildebrandt, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pressure-volume+data+of+cat+lung+interpreted+by+a+plastoelastic,+linear+viscoelastic+model.">Pressure-volume data of cat lung interpreted by a plastoelastic, linear viscoelastic model.</a> J. Appl. Physiol. 28, 365-372 (1970).</li><li>Hoppin, F. G., Hildebrandt, J., West, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Bioengineering Aspects of the Lung. , 83-162 (1977).</li><li>Avery, M. E., Mead, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+properties+in+relation+to+atelectasis+and+hyaline+membrane+disease).">Surface properties in relation to atelectasis and hyaline membrane disease).</a> AMA. J. Dis. Child. 97, 517-523 (1959).</li><li>Clements, J. A., Hustead, R. F., Johnson, R. P., Gribetz, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulmonary+surface+tension+and+alveolar+stability.">Pulmonary surface tension and alveolar stability.</a> Tech Rep CRDLR US Army Chem. Res. Dev. Lab. 3052, 1-24 (1961).</li><li>Radford, E. P., Remington, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Tissue Elasticity. , 177-190 (1957).</li><li>Mitzner, W., Johnson, J. W. C., Scott, R., London, W. T., Palmer, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+betamethasone+on+the+pressure-volume+relationship+of+fetal+rhesus+monkey+lung.">Effect of betamethasone on the pressure-volume relationship of fetal rhesus monkey lung.</a> Journal of Applied Physiology. 47, 377-382 (1979).</li><li>Smaldone, G. C., Mitzner, W., Itoh, H. <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+alveolar+recruitment+in+lung+inflation:+Influence+on+pressure-volume+hysteresis.">The role of alveolar recruitment in lung inflation: Influence on pressure-volume hysteresis.</a> Journal of Applied Physiology. 55, 1321-1332 (1983).</li><li>Tankersley, C. G., Rabold, R., Mitzner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+lung+mechanics+are+genetically+determined+in+inbred+murine+strains.">Differential lung mechanics are genetically determined in inbred murine strains.</a> Journal of Applied Physiology. 86, 1764-1769 (1999).</li><li>Soutiere, S. E., Mitzner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+defining+total+lung+capacity+in+the+mouse.">On defining total lung capacity in the mouse.</a> J. Appl. Physiol. 96, 1658-1664 (2004).</li><li>Stengel, P. W., Frazer, D. G., Weber, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lung+degassing:+an+evaluation+of+two+methods.">Lung degassing: an evaluation of two methods.</a> Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology. 48, 370-375 (1980).</li><li>Limjunyawong, N., Mitzner, W., Horton, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+mouse+model+of+chronic+idiopathic+pulmonary+fibrosis.">A mouse model of chronic idiopathic pulmonary fibrosis.</a> Physiol Rep. 2, e00249 (2014).</li><li>Fallica, J., Das, S., Horton, M. R., Mitzner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+Carbon+Monoxide+Diffusing+Capacity+in+the+Mouse+Lung.">Application of Carbon Monoxide Diffusing Capacity in the Mouse Lung.</a> J. Appl. Physiol. 110, 1455-1459 (2011).</li><li>Brown, R. H., 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=The+structural+basis+of+airways+hyperresponsiveness+in+asthma.">The structural basis of airways hyperresponsiveness in asthma.</a> J. Appl. Physiol. 101 (1), 30-39 (2006).</li><li>Smargiassi, 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=Ultrasonographic+Assessment+of+the+Diaphragm+in+Chronic+Obstructive+Pulmonary+Disease+Patients:+Relationships+with+Pulmonary+Function+and+the+Influence+of+Body+Composition+-+A+Pilot+Study.">Ultrasonographic Assessment of the Diaphragm in Chronic Obstructive Pulmonary Disease Patients: Relationships with Pulmonary Function and the Influence of Body Composition - A Pilot Study.</a> Respiration: International Review of Thoracic Diseases. 87 (5), 364-371 (2014).</li><li>Mitzner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Airway-parenchymal+interdependence.">Airway-parenchymal interdependence.</a> Comprehensive Physiol. 2, 1921-1935 (2012).</li><li>Johnson, J. W., Permutt, S., Sipple, J. H., Salem, E. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Intra-Alveolar+Fluid+on+Pulmonary+Surface+Tension+Properties.">Effect of Intra-Alveolar Fluid on Pulmonary Surface Tension Properties.</a> J. Appl. Physiol. 19, 769-777 (1964).</li><li>Palmer, S., Morgan, T. E., Prueitt, J. L., Murphy, J. H., Hodson, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lung+development+in+the+fetal+primate,+Macaca+nemestrina.+II.+Pressure-volume+and+phospholipid+changes.">Lung development in the fetal primate, Macaca nemestrina. II. Pressure-volume and phospholipid changes.</a> Pediatr. Res. 11, 1057-1063 (1977).</li><li>Lum, H., Mitzner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+species+comparisonof+alveolar+size+and+surface+forces.">A species comparisonof alveolar size and surface forces.</a> Journal of Applied Physiology. 62, 1865-1871 (1987).</li><li>Faridy, E. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+distension+on+release+of+surfactant+in+excised+dogs'+lungs.">Effect of distension on release of surfactant in excised dogs' lungs.</a> Respir. Physiol. 27, 99-114 (1976).</li><li>Faridy, E. E., Permutt, S., Riley, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+ventilation+on+surface+forces+in+excised+dogs'+lungs.">Effect of ventilation on surface forces in excised dogs' lungs.</a> J. Appl. Physiol. 21, 1453-1462 (1966).</li><li>Comroe, J. H., Forster, R. E., Dubois, A. B., Briscoe, W. A., Carlsen, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Lung: Clinical Physiology and Pulmonary Function Tests. , (1962).</li><li>Martinez, F. J., 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=The+clinical+course+of+patients+with+idiopathic+pulmonary+fibrosis.">The clinical course of patients with idiopathic pulmonary fibrosis.</a> Ann. Intern. Med. 142, 963-967 (2005).</li></ol>

None of the authors have any financial interests that would be in conflict with the material presented in this paper.

在本文中一个简单的可重复的方法已经描述在小鼠中测定表型肺的弹性，总肺的PV曲线的经典方法。这样的曲线是有助于肺表面活性物质的发现及其在肺部提供稳定的重要性。这里，示出了如何在PV曲线也提供以测量在成年小鼠肺有关肺弹性几个变量的装置是有用的。有在所有的变量在两个常用的小鼠模型高度显著变化以产生在小鼠肺中的病理改变。以下部分简要讨论的变化中的每个所测量的变量...

鼠标是目前各种肺部疾病的主要动物模型。肺气肿或纤维化模型，基本的表型变化，最好通过测量变化肺弹性评估。虽然有许多方法测量弹性，经典方法是总压力容积（PV）曲线从残气量（RV）的测量，以总肺活量（TLC）的那个。这种测量已经取得了对成人肺部几乎所有的哺乳动物物种距今近100年1-3。这样的PV曲线也是在胎儿肺发育4-7肺表面活性物质功能的发现和了解发挥了重要作用。尽管PV曲线的重要性，因为肺的表型的测定，还没有标准的方式来执行这种测量。它已经做了简单的通过充气和放气与离散的步骤肺（等待可变的时间后，每个平衡）或泵的可以连续地充气和放气的肺。的PV曲线往往是做在零和一些用户自定义的肺活量之间的体积范围内，但报道的不同实验室每个压力容积循环的持续时间已经非常可变的，从几秒8变到2小时。一些研究者参考本总肺PV曲线为静态或准静态的，但这些都是质量方面，提供小的洞察力，并且它们在这里不使用。此外，PV曲线并没有被广泛报道，在小鼠，尽管事实上，它可以提供关于在肺结构变化的宏观效应的有用信息。 几个问题导致变异PV曲线收购，包括:通货膨胀和通货紧缩1）速度; 2）压力为游览通胀和通缩;和3）的装置，以确定一个绝对肺容积的测量。在该方法中存在这里，3毫升/分钟的速度被选为一项妥协即，成为不能太短，以反映与正常的通风，而不是太慢关联的动态弹性，以使测量不切实际的，学习大队列时尤为如此。由于标称总肺活量在C57BL / 6小鼠的健康是1.2毫升9的量级，这种速度通常允许两个完整的闭合回路的PV将在约1.5分钟完成。 在其中，PV曲线已经报道了在扩展文献中，使用的峰值充气压力一直非常可变的，从低到20变化到40厘米水柱2 O.这个变异性的一部分可能与物种，但设置的PV曲线压力上限的一个主要目标是充气肺总肺活量（TLC）或最大的肺容积。在TLC在人类是由最大的志愿工作，个人可以做出规定，但不幸的是这可能从来没有在任何动物模型中被复制。因此，在实验PV曲线的最大音量是威慑由最大压力由研究者任意设定开采。我们的目标是建立一个压力，其中所述PV曲线是平坦的，但不幸的是哺乳动物的肺PV曲线的膨胀肢是从不平坦的。所以大多数研究者设定一个压力，其中所述膨胀曲线开始变平基本上，典型30厘米H 2 O在小鼠，然而，PV曲线更为复杂与充气肢双驼峰，并且其中该膨胀肢常常仍然在30厘米水柱2 O 10急剧上升，所以30不是为一个好的结束点PV曲线。出于这个原因，我们使用35厘米的H 2 O为压力极限为鼠标PV曲线，这是在该充气四肢我们已审查所有菌株的开始变平的压力。 由于PV曲线本身很非线性的，光伏环的外观将取决于从弯道开始处的体积。一些商业通风允许用户做大型光伏循环，从初始的F钢筋混凝土，但如果将FRC体积是未知的话，是不可能解读的改变与任何病理，例如PV曲线，因为这些变化可以简单地从开始体积的变化造成的，而不是结构改变在肺中。因此，没有一个绝对量的测量，PV曲线几乎是不可能的解释，因此没有什么效用。虽然，有几种方法来测量肺容积，这些往往笨重，需要特殊的设备。在这里所描述的简单的方法，所述PV曲线的体内脱气过程后从零开始体积。 总之，本文说明了一个简单的方法，以规范肺PV曲线的测量在小鼠肺，并限定可从该曲线被链接到肺的结构来计算几个度量。的PV曲线因此提供肺功能测试具有在能够检测小鼠通讯表型的结构变化的直接应用肺疾病如肺气肿和纤维化。

<table border="0" cellpadding="0" cellspacing="0" width="692">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Name of Material/ Equipment</td>
			<td style="width:127px;">Company</td>
			<td style="width:155px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;"></td>
			<td style="width:127px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;"></td>
			<td style="width:127px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:244px;">&#160;Syringe Pump</td>
			<td style="width:127px;">Harvard Apparatus</td>
			<td>55-2226</td>
			<td>Infuse/Withdraw syringe pump</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Pump 22 Reversing Switch&#160;</td>
			<td style="width:127px;">Harvard Apparatus</td>
			<td>552217</td>
			<td>&#160;included with pump</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:127px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Linear displacement transformer</td>
			<td style="width:127px;">Trans-Tek, Inc.</td>
			<td style="width:155px;">0244-0000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;"></td>
			<td style="width:127px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">5 mL glass syringe</td>
			<td style="width:127px;">Becton Dickenson</td>
			<td style="width:155px;"></td>
			<td>Several other possible vendors</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;"></td>
			<td style="width:127px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Digital recorder</td>
			<td style="width:127px;">ADInstruments</td>
			<td>PL3504</td>
			<td>Several other possible vendors</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Bridge Amp Signal Conditioner</td>
			<td style="width:127px;">ADInstruments</td>
			<td>FE221</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:127px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Gas tank,100% oxygen</td>
			<td style="width:127px;">Airgas, Inc</td>
			<td style="width:155px;"></td>
			<td>Any supplier or hospital source will work</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;"></td>
			<td style="width:127px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pressure Transducer - 0-1psi&#160; millivolt output</td>
			<td>Omega Engineering</td>
			<td>PX-137</td>
			<td>Range: &#8776;0-60 cmH2O</td>
		</tr>
	</tbody>
</table>

measurement of the pressure-volume curve in mouse lungs

近几十年来鼠标已经成为了各种肺部疾病的主要动物模型。在肺气肿或纤维化模型中，必不可少的表型变化，最好是由变化在肺弹性测量评估。到最好的理解小鼠这样的病状底层的具体机制，它是必不可少的，以使功能测量能反映显影病理。虽然有许多方法测量弹性，经典方法是，总肺压力容积（PV）的曲线进行过肺容积的整个范围。这种测量已经取得了对成人肺部几乎所有的哺乳动物物种距今近100年了，这样的PV曲线也是在胎儿肺发育肺表面活性物质功能的发现和了解发挥了重要作用。不幸的是，这样的总的PV曲线还没有得到广泛报道，在小鼠，尽管事实上，它们可以提供对macrosc有用信息在肺的结构变化OPIC影响。尽管局部的PV曲线测量刚刚变化肺容积有时报道，没有绝对的体积的量度，总的PV曲线的非线性性质使得这些部分的那些非常难以解释。在本研究中，我们描述一个标准化的方法来测量总PV曲线。我们然后测试这些曲线来检测在两个常见肺病理学，肺气肿和纤维化改变小鼠肺结构的能力。结果显示，与这些疾病预期的结构性变化一致的几个变量显著的变化。小鼠肺PV曲线的该测量从而提供了一种简单的装置来监视随时间变化的病理生理改变和治疗程序的潜在影响的进展。

虽然为光伏曲线的步骤中演示了仅用于控制健康小鼠的视频中，我们检查了PV曲线来检测小鼠的功能和病理变化与两个不同的常见病症，肺气肿和纤维化的能力。这些传统车型的详细信息在其他地方12,13描述。很简单，麻醉用3％异氟醚后肺气肿是由3个或6ü猪胰弹性蛋白酶灌输到气管引起的，研究3周后，和纤维化是由0.05ü博莱霉素灌输到气管引起的，在此之后的研究2周侮辱。 <p class="jov...

Watch this Scientific Journal Video about Measurement of the Pressure-volume Curve in Mouse Lungs at JoVE.com

Measurement of the Pressure-volume Curve in Mouse Lungs

Here we present a protocol to simply and reliably measure the lung pressure-volume curve in mice, showing that it is sufficiently sensitive to detect phenotypic parenchymal changes in two common lung pathologies, pulmonary fibrosis and emphysema. This metric provides a means to quantify the lung&#8217;s structural changes with developing pathology.

在小鼠肺压力容积曲线的测量

In recent decades the mouse has become the primary animal model of a variety of lung diseases. In models of emphysema or fibrosis, the essential ...

measurement-of-the-pressure-volume-curve-in-mouse-lungs

Research

Education

JoVE Core

JoVE Journal

Physics

Medicine

Unit 1

The Kinetic Theory of Gases

SCIENTISTS IN ACTION

18.5K 次观看.  Johns Hopkins University. Here we present a protocol to simply and reliably measure the lung pressure-volume curve in mice, showing that it is sufficiently sensitive to detect phenotypic parenchymal changes in two common lung pathologies, pulmonary fibrosis and emphysema. This metric provides a means to quantify the lung’s structural changes with developing pathology.

视频: Measurement of the Pressure-volume Curve in Mouse Lungs

The Measurement and Treatment of Suppression in Amblyopia

Amblyopia, a developmental disorder of the visual cortex, is one of the leading causes of visual dysfunction in the working age population. Current estimates put the prevalence of amblyopia at approximately 1-3%1-3, the majority of cases being monocular2. Amblyopia is most frequently caused by ocular misalignment (strabismus), blur induced by unequal refractive error (anisometropia), and in some cases by form deprivation.
Although amblyopia is initially caused by abnormal visual input in infancy, once established, the visual deficit often remains when normal visual input has been restored using surgery and/or refractive correction. This is because amblyopia is the result of abnormal visual cortex development rather than a problem with the amblyopic eye itself4,5 . Amblyopia is characterized by both monocular and binocular deficits6,7 which include impaired visual acuity and poor or absent stereopsis respectively. The visual dysfunction in amblyopia is often associated with a strong suppression of the inputs from the amblyopic eye under binocular viewing conditions8. Recent work has indicated that suppression may play a central role in both the monocular and binocular deficits associated with amblyopia9,10 .
Current clinical tests for suppression tend to verify the presence or absence of suppression rather than giving a quantitative measurement of the degree of suppression. Here we describe a technique for measuring amblyopic suppression with a compact, portable device11,12 . The device consists of a laptop computer connected to a pair of virtual reality goggles. The novelty of the technique lies in the way we present visual stimuli to measure suppression. Stimuli are shown to the amblyopic eye at high contrast while the contrast of the stimuli shown to the non-amblyopic eye are varied. Patients perform a simple signal/noise task that allows for a precise measurement of the strength of excitatory binocular interactions. The contrast offset at which neither eye has a performance advantage is a measure of the "balance point" and is a direct measure of suppression. This technique has been validated psychophysically both in control13,14 and patient6,9,11 populations.
In addition to measuring suppression this technique also forms the basis of a novel form of treatment to decrease suppression over time and improve binocular and often monocular function in adult patients with amblyopia12,15,16 . This new treatment approach can be deployed either on the goggle system described above or on a specially modified iPod touch device15.

Amblyopia is a developmental disorder of the visual cortex that is often accompanied by strong suppression of one eye. We present a new technique for measuring and treating interocular suppression in patients with amblyopia that can be deployed using virtual reality goggles or a portable iPod Touch device.

测量和制止在弱视治疗

Amblyopia, a developmental disorder of the visual cortex, is one of the leading causes of visual dysfunction in the working age population. Current ...

科研

医学

In vivo Measurement of the Mouse Pulmonary Endothelial Surface Layer

The endothelial glycocalyx is a layer of proteoglycans and associated glycosaminoglycans lining the vascular lumen. In vivo, the glycocalyx is highly hydrated, forming a substantial endothelial surface layer (ESL) that contributes to the maintenance of endothelial function. As the endothelial glycocalyx is often aberrant in vitro and is lost during standard tissue fixation techniques, study of the ESL requires use of intravital microscopy. To best approximate the complex physiology of the alveolar microvasculature, pulmonary intravital imaging is ideally performed on a freely-moving lung. These preparations, however, typically suffer from extensive motion artifact. We demonstrate how closed-chest intravital microscopy of a freely-moving mouse lung can be used to measure glycocalyx integrity via ESL exclusion of fluorescently-labeled high molecular weight dextrans from the endothelial surface. This non-recovery surgical technique, which requires simultaneous brightfield and fluorescent imaging of the mouse lung, allows for longitudinal observation of the subpleural microvasculature without evidence of inducing confounding lung injury.

In vivo Measurement of the Mouse Pulmonary Endothelial Surface Layer

The endothelial glycocalyx/endothelial surface layer is ideally studied using intravital microscopy. Intravital microscopy is technically challenging in a moving organ such as the lung. We demonstrate how simultaneous brightfield and fluorescent microscopy may be used to estimate endothelial surface layer thickness in a freely-moving in vivo mouse lung.

在体测量小鼠肺血管内皮表面层

The endothelial glycocalyx is a layer of proteoglycans and associated glycosaminoglycans lining the vascular lumen. In vivo, the glycocalyx is highly ...

Technical Aspects of the Mouse Aortocaval Fistula

Technical aspects of creating an arteriovenous fistula in the mouse are discussed. Under general anesthesia, an abdominal incision is made, and the aorta and inferior vena cava (IVC) are exposed. The proximal infrarenal aorta and the distal aorta are dissected for clamp placement and needle puncture, respectively. Special attention is paid to avoid dissection between the aorta and the IVC. After clamping the aorta, a 25 G needle is used to puncture both walls of the aorta into the IVC. The surrounding connective tissue is used for hemostatic compression. Successful creation of the AVF will show pulsatile arterial blood flow in the IVC. Further confirmation of successful AVF can be achieved by post-operative Doppler ultrasound.

The goal is to produce an arteriovenous fistula that is simple and reproducible. This method does not use sutures or glue adhesive. Therefore the samples can be used with the least amount of foreign materials for analysis.

在的鼠标Aortocaval瘘的技术方面

Technical aspects of creating an arteriovenous fistula in the mouse are discussed. Under general anesthesia, an abdominal incision is made, and the aorta ...

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 ...

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 ...

Preparation Steps for Measurement of Reactivity in Mouse Retinal Arterioles Ex Vivo

Vascular insufficiency and alterations in normal retinal perfusion are among the major factors for the pathogenesis of various sight-threatening ocular diseases, such as diabetic retinopathy, hypertensive retinopathy, and possibly glaucoma. Therefore, retinal microvascular preparations are pivotal tools for physiological and pharmacological studies to delineate the underlying pathophysiological mechanisms and to design therapies for the diseases. Despite the wide use of mouse models in ophthalmic research, studies on retinal vascular reactivity are scarce in this species. A major reason for this discrepancy is the challenging isolation procedures owing to the small size of these retinal blood vessels, which is ~ &#8804; 30 &#181;m in luminal diameter. To circumvent the problem of direct isolation of these retinal microvessels for functional studies, we established an isolation and preparation technique that enables ex vivo studies of mouse retinal vasoactivity under near-physiological conditions. Although the present experimental preparations will specifically refer to the mouse retinal arterioles, this methodology can readily be employed to microvessels from rats.

Preparation Steps for Measurement of Reactivity in Mouse Retinal Arterioles Ex Vivo

Many vision-threatening ocular diseases are associated with dysfunctional retinal microvessels. Therefore, the measurement of retinal arteriole responses is important to investigate the underlying pathophysiological mechanisms. This article describes a detailed protocol for mouse retinal arteriole isolation and preparation to assess the effects of vasoactive substances on vascular diameter.

小鼠视网膜微动脉的反应性测定的制备步骤前体

Vascular insufficiency and alterations in normal retinal perfusion are among the major factors for the pathogenesis of various sight-threatening ocular ...

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

Acute myocardial infarction can lead to acute heart failure and cardiogenic shock. The evaluation of hemodynamics is critical for the evaluation of any potential therapeutic approach directed against acute left ventricular (LV) dysfunction. Current imaging modalities (e.g., echocardiography and magnetic resonance imaging) have several limitations since data on LV pressure cannot directly be measured. LV catheterization in mice undergoing coronary artery occlusion could serve as a novel method for a real-time evaluation of LV function.
At the beginning of the procedure, mice were anesthetized followed by endotracheal intubation. For LV catheterization, the right carotid artery was exposed via middle-neck incision. The catheter was introduced and placed into the LV cavity. Left thoracotomy was conducted and the left main coronary artery (LCA) was ligated. To induce reperfusion, the suture was released after 45 min. Pressure-volume data was recorded at all times.
Ligation of the LCA caused a decrease in LV systolic function as evidenced by a 30% reduction in stroke volume, LV ejection fraction (EF), and cardiac output. Maximum dP/dt as a parameter for LV contractility was also significantly reduced and diastolic function was severely impaired (minimum dP/dt -40%). Reperfusion over a period of 20 min did not lead to a complete recovery of LV function.
Real-time pressure-volume analysis served as a valid procedure for monitoring cardiac function during acute myocardial infarction in mice. Maintaining stable anesthesia and a standardized surgical approach was crucial to ensure valid results. As the early phase of acute myocardial infarction is critical for morbidity and mortality, the delineated method could be beneficial for preclinical evaluation of new strategies for cardioprotection.

Acute myocardial infarction in mice induces acute but incompletely characterized changes in left ventricular (LV) function. LV catheterization in mice undergoing coronary artery occlusion serves as a novel method for a real-time evaluation of LV function.

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 ...

Echocardiographic Measurement of Right Ventricular Diastolic Parameters in Mouse

Diastolic dysfunction is a prominent feature of right ventricular (RV) remodeling associated with conditions of pressure overload. However, the RV diastolic function is rarely quantified in experimental studies. This might be due to technical difficulties in the visualization of the RV in the apical four-chamber view in rodents. Here we describe two positions facilitating the visualization of the apical four-chamber view in mice to assess the RV diastolic function.
The apical four-chamber view is enabled by tilting the mouse fixation platform to the left and caudally (LeCa) or to the right and cranially (RiCr). Both positions provide images of comparable quality. The results of the RV diastolic function obtained from two positions are not significantly different. Both positions are comparably easy to perform. This protocol can be incorporated into published protocols and enables detailed investigations of the RV function.

Here we describe and compare two positions for obtaining the apical four-chamber view in mice. These positions enable the quantification of the right ventricular function, provide comparable results, and can be used interchangeably.

小鼠右心室舒张参数的超声心电图测量

Diastolic dysfunction is a prominent feature of right ventricular (RV) remodeling associated with conditions of pressure overload. However, the RV ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

用线 Myography 测定小鼠肠系膜动脉的等轴收缩力

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

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) ...