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

基本信息

批准号：
9252529
负责人：
Matthew W. Kay
金额：
$ 19.06万
依托单位：
GEORGE WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2019-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9252529
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 Hemoglobin A 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 Oxides 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 experimental study fluorescence imaging fluorophore imaging study improved metabolic abnormality assessment novel oxidation product development public health relevance response

项目摘要

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（由申请人提供）：离体灌注心脏是研究心脏力学、代谢和电生理学的有用模型，其主要缺点是基于晶体的灌注液，例如 Krebs-Henseleit 溶液（KHS），不能维持足够的心肌。全氟化碳 (PFC) 是一种流行的人造 O2 载体，并且正在积极研究其临床用途，但由于安全问题，其开发大多已停止。 PFC 乳液商业来源的丧失给科学界带来了痛苦，因为 PFC 对于灌注心脏研究和组织工程方法特别有价值，但尚未满足证明各个实验室可以“内部”制造 PFC 乳液的需求。此外，与荧光成像（包括光学绘图）兼容的富氧灌注液将显着提高此类研究的生理意义，尤其是在氧合不足的灌注心脏制剂中测试日益复杂的心脏病假设。光学测绘系统的发展使得能够在收缩的心脏中进行测绘——具有非常高氧气需求的制剂，证明 PFC 灌注液可以维持心肌氧合并提供氧气储备，同时不会显着干扰心肌功能的可见光光学评估，这肯定会建立一种新的方法。我们的目标是使用定制的 PFC 乳剂在灌注心脏研究中提供氧储备并重建生理冠状动脉流速，以便心肌代谢、原位线粒体。我们还将使用一种新颖的运动跟踪光学映射方法来阐明基于 PFC 的氧合对肌膜 KATP 通道激活的影响。通过APD变化）、心率和传导速度在完全工作的离体兔心脏准备中我们的主要目标是。严格证明基于 PFC 的灌注液和具有运动跟踪功能的光学测绘是研究离体心脏的能量学和电生理学的强大组合。第一个目标是确定维持肌红蛋白氧合和氧化所需的 PFC 浓度（重量/体积）。第二个目的是测量 PFC 对几种常见荧光团（包括）荧光信号衰减的影响。 di-4-ANEPPS、RH237、Rhod-2AM 和 BCECF 第三个目标是光学绘制离体双心室工作心脏 PFC 灌注前后 APD 和 CV 的变化。该项目开发的方法可应用于任何灌注器官。实验，对基础全心研究产生具体而实质性的影响。