Oxygen-rich perfusate that is compatible with optical assessments of myocardial physiology

与心肌生理学光学评估兼容的富氧灌注液

• 批准号: 9112060
• 负责人: Matthew W. Kay
• 金额: $ 21.53万
• 依托单位: GEORGE WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9112060
• 关键词: Attenuated; Basic Science; Binding; Blood; Blood Vessels; Cardiac; Cardiovascular system; Clinical; Communities; Consumption; Contracts; Coronary; Custom; Development; Disadvantaged; Disease; Electrophysiology (science); Emulsions; Erythrocytes; Fluorescence; Fluorocarbons; Gap Junctions; Glyburide; Goals; Heart; Heart Arrest; Heart Diseases; Heart Rate; Heart Research; Hemoglobin; Housing; In Situ; Individual; Laboratories; Laboratory Research; Maps; Measurement; Measures; Mechanics; Metabolic; Metabolism; Mitochondria; Morphologic artifacts; Motion; Myocardial; Myocardium; Myoglobin; Optics; Organ; Oryctolagus cuniculus; Oxidation-Reduction; Oxygen; Perfusion; Pharmacologic Substance; Physiological; Physiology; Preparation; Probability; Safety; Signal Transduction; Source; Study models; System; Testing; Tissue Engineering; Vasodilation; Visible Radiation; Weight; Work; Workload; attenuation; base; crystalloid; fluorescence imaging; fluorophore; improved; meetings; metabolic abnormality assessment; novel; oxidation; product development; public health relevance; research study; response

 DESCRIPTION (provided by applicant): The isolated perfused heart is a useful model for studying cardiac mechanics, metabolism, and electrophysiology. Its critical disadvantage is that crystalloid-based perfusate, such as Krebs-Henseleit solution (KHS), does not maintain adequate myocardial oxygenation, especially when metabolic demand is high. Perfluorocarbons (PFC) were a popular artificial O2 carrier and were actively studied for clinical use, although development has mostly ceased due to safety concerns. The loss of commercial sources of PFC emulsions detrimentally impacts the scientific community because PFC are particularly valuable for perfused heart studies and tissue engineering approaches. There is an unmet need to demonstrate that individual laboratories can make a PFC emulsion "in-house", with the goal of enabling increasingly sophisticated hypotheses of cardiac disease to be tested in adequately oxygenated perfused heart preparations. Additionally, an oxygen-rich perfusate that is compatible with fluorescence imaging, including optical mapping, will dramatically elevate the physiological significance of such studies, especially as optical mapping systems evolve to enable mapping in contracting hearts -- preparations that have a very high oxygen demand. Demonstrating that PFC perfusate maintains myocardial oxygenation and provides oxygen reserve while not substantially interfering with visible-light optical assessments of myocardial function will surely establish a new paradigm for excised heart studies. Our objective is use a custom-made PFC emulsion to provide oxygen reserve in perfused heart studies and reestablish physiological coronary flow rates, such that myocardial metabolism, in-situ mitochondrial function, and electrophysiology can be studied without physiological artifacts associated with inadequate oxygenation, such as KATP channel activation and vasodilation. We will also use a novel motion-tracking optical mapping approach to elucidate the effects of PFC-based oxygenation on sarcolemmal KATP channel activation (via APD changes), heart rate, and conduction velocity in fully working isolated rabbit heart preparations. Our primary goal is to rigorously show that a PFC-based perfusate and optical mapping with motion tracking is a powerful combination for studying energetics and electrophysiology in excised hearts. The first Aim is to determine the PFC concentration (weight/vol) that is required to maintain myoglobin oxygenation and oxidation of the ETC for excised hearts that are arrested, contracting, and working. The second Aim is to measure the effect of PFC on the fluorescence signal attenuation of several common fluorophores, including di-4-ANEPPS, RH237, Rhod- 2AM, and BCECF. The third Aim is to optically map changes in APD and CV before and after PFC perfusion in excised biventricular working hearts. Approaches developed in this project could be applied in any perfused organ experiment, having specific and substantial impact on basic whole-heart research.

 描述（由适用提供）：孤立的灌注心脏是研究心脏力学，代谢和电生理学的有用模型。它的关键灾难是，基于结晶的灌注液，例如Krebs-Henseleit溶液（KHS），并不能保持足够的心肌氧合，尤其是当代谢需求较高时。全氟化合物（PFC）是一种流行的人造O2载体，并且在临床上进行了积极研究，尽管由于安全问题，开发主要停止。 PFC乳液的商业来源丧失会对科学界有害，因为PFC对于灌注心脏研究和组织工程方法特别有价值。尚无满足的需要证明，个别实验室可以在内部“内部”制作PFC乳液，目的是使越来越复杂的心脏病假设在充分氧合的灌注心脏制剂中进行测试。此外，与荧光成像相兼容的富氧灌注液（包括光学映射）将显着提高此类研究的物理意义，尤其是随着光学映射系统的发展，可以在合同心中绘制映射 - 氧气需求很高的制剂。证明PFC灌注液可维持心肌充氧并提供氧气储备，同时没有实质上干扰对心肌功能的可见光光学评估，这肯定会为出色的心脏研究建立新的范式。我们的目标是使用定制的PFC乳液在灌注心脏研究中提供氧气储备，并重新建立身体冠状动脉流量，从而可以在没有与氧气不足的katp Channel Activation和Vasodyation和Vasodyation相关的情况下研究心肌代谢，原位线粒体功能和电生理学。我们还将使用一种新型的运动跟踪光学映射方法来阐明基于PFC的氧合对肌膜KATP通道激活（通过APD变化），心率和传导速度在完全工作的孤立兔心脏制剂中的影响。我们的主要目标是 严格地表明，具有运动跟踪的基于PFC的灌注液和光学映射是研究出色心脏中能量和电生理学的强大组合。第一个目的是确定维持肌红蛋白氧合和ETC的氧化所需的PFC浓度（重量/VOL），以使其被捕，收缩和工作的出色心脏。第二个目的是测量PFC对几种常见荧光团的荧光信号衰减的影响，包括DI-4-Anepps，RH237，Rhod-2am和BCECF。第三个目的是在PFC灌注前后在出色的双脑室工作心脏中进行光学绘制APD和CV的变化。该项目中开发的方法可以应用于任何灌注器官实验中，对基本的全心研究具有特定而实质性的影响。