EPR oximetry in the beating heart: Myocardial oxygen consumption rate as an index of postischemic recovery
Year: 2004
Type: article
Abstract: Oxygen plays a critical role in the pathophysiology of myocardial injury during both ischemia and subsequent reperfusion (I/R). Thus, oxygen concentration is an important variable to measure during I/R. In the present work, electron paramagnetic resonance (EPR)-based oximetry was used to measure the oxygen concentration during a series of I/R episodes and oxygenation levels were correlated with the contractile and hemodynamic functions of the heart. A custom-developed electronically tunable surface coil resonator working at 1.1 GHz was used to determine tissue pO(2) in the beating heart. Microcrystalline particulate of lithium phthalocyanine was used as an EPR oximetry probe. Isolated and perfused rat hearts were subjected to 1 or 3 hr durations of preischemic perfusion, followed by 15-min I/R cycles. In hearts perfused for 3 hr prior to 15-min I/R cycles, the myocardial pO(2) decreased gradually on subsequent reperfusions of three successive I/R cycles. However, in hearts perfused for 1 hr there was almost 100% recovery of myocardial pO(2) in all three I/R cycles. The extent of oxygenation recovered in each reperfusion cycle correlated with the recovery of hemodynamic and contractile function. The results also showed that the oxygen consumption rate of the heart at the end of each I/R episode decreased in direct proportion to the functional recovery. In summary, it was observed that the amount of myocardial oxygen consumption during I/R could provide a reliable index of functional impairment in the heart.
Source: Magnetic Resonance in Medicine
DOI: 10.1002/mrm.20000
Institution: The Ohio State University
Language: English
Subfield: Pathology and Forensic Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
Awards: G1040317719, EPR Imaging of Tumor Heterogeneity and Oxygenation, IN VIVO EPR IMAGING OF FREE RADICALS AT 300 MHZ, G4468874155, G4566214955, G4771711442, CENTER FOR BIOMEDICAL EPR SPECTROSCOPY AND IMAGING, G7434693567, IN VIVO EPR IMAGING OF FREE RADICALS AT 300 MHZ, CENTER FOR BIOMEDICAL EPR SPECTROSCOPY AND IMAGING
OpenAlex ID: W2033599145
