Characterization of in vivo tissue redox status, oxygenation, and formation of reactive oxygen species in postischemic myocardium.
The current study aims to characterize the alterations of in vivo tissue redox status, oxygenation, formation of reactive oxygen species (ROS), and their effects on the postischemic heart. Mouse heart was subjected to 30 min LAD occlusion, followed by 60 min reperfusion. In vivo myocardial redox status and oxygenation were measured with electron paramagnetic resonance (EPR). In vivo tissue NAD(P)H and formation of ROS were monitored with fluorometry. Tissue glutathione/glutathione disulfide (GSH/GSSG) levels were detected with high-performance liquid chromatography (HPLC). These experiments demonstrated that tissue reduction rate of nitroxide was increased 100% during ischemia and decreased 33% after reperfusion compared to the nonischemic tissue. There was an overshoot of tissue oxygenation after reperfusion. Tissue NAD(P)H levels were increased during and after ischemia. There was a burst formation of ROS at the beginning of reperfusion. Tissue GSH/GSSG level showed a 48% increase during ischemia and 29% decrease after reperfusion. In conclusion, the hypoxia during ischemia limited mitochondrial respiration and caused a shift of tissue redox status to a more reduced state. ROS generated at the beginning of reperfusion caused a shift of redox status to a more oxidized state, which may contribute to the postischemic myocardial injury.
Zhu
Xuehai
X
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, The Ohio State University College of Medicine, Columbus, Ohio 43210, USA.
Zuo
Li
L
Cardounel
Arturo J
AJ
Zweier
Jay L
JL
He
Guanglong
G
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004578:Electron Spin Resonance Spectroscopy; D005978:Glutathione / Q000378:metabolism; D019803:Glutathione Disulfide / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D015428:Myocardial Reperfusion Injury / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism*
D017382:Reactive Oxygen Species; D009249:NADP; D005978:Glutathione; D019803:Glutathione Disulfide