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Effects of flow and energy metabolism on injury and Rb + uptake in pig hearts: An 87 Rb and 31 P NMR study
Author(s) -
Kupriyanov Valery V.,
Sun Jiankang,
Jilkina Olga,
Dai Guangping,
Deslauriers Roxanne
Publication year - 2001
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1283
Subject(s) - phosphocreatine , perfusion , chemistry , metabolism , blood flow , ischemia , fissipedia , nuclear magnetic resonance , medicine , energy metabolism , biochemistry , physics
In this work the roles of coronary flow (CF) and metabolism in Rb + (K + congener) uptake were studied. In isolated pig hearts the left anterior descending artery (LAD) was cannulated to maintain adequate perfusion of the LAD bed. Rb + loading was initiated and the LAD flow was either completely stopped (no flow (NF)) or reduced to 12% (low flow (LF)), or buffer was deoxygenated without change in flow (hypoxic flow (HYP)) for 2 h. CF through the LAD was then restored to normal, or perfusion was switched to oxygenated buffer. Serial 87 Rb MR images or localized 31 P spectra were acquired to compare the Rb + uptake and energetics in the left ventricular (LV) anterior (ischemic/hypoxic) and posterior (normal) walls. End‐ischemic/hypoxic 87 Rb signal intensities in the anterior wall were higher and the fluxes were greater in the HYP and LF groups than in the NF group. Phosphocreatine and ATP decreased less significantly and recovered better in the HYP and LF groups. Upon reperfusion/reoxygenation, the HYP and LF groups showed higher 87 Rb signal intensities and smaller or no infarctions in the anterior wall compared to those in the NF group. Ischemia reduces Rb + uptake due to both flow limitations and metabolic inhibition of cellular transport. 87 Rb MRI has a potential for distinguishing necrotic and reversibly damaged tissue. Magn Reson Med 46:963–973, 2001. © 2001 Wiley‐Liss, Inc.