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Inhibition of carbohydrate oxidation during the first minute of reperfusion after brief ischemia: NMR detection of hyperpolarized 13 CO 2 and H 13 CO 3 −
Author(s) -
Merritt Matthew E.,
Harrison Crystal,
Storey Charles,
Sherry A. Dean,
Malloy Craig R.
Publication year - 2008
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.21760
Subject(s) - phosphocreatine , lactate dehydrogenase , chemistry , ischemia , oxygen , alanine , pyruvic acid , dehydrogenase , cytosol , pyruvate dehydrogenase complex , metabolism , biochemistry , enzyme , medicine , energy metabolism , amino acid , organic chemistry
Isolated rat hearts were studied by 31 P NMR and 13 C NMR. Hyperpolarized [1‐ 13 C]pyruvate was supplied to control normoxic hearts and production of [1‐ 13 C]lactate, [1‐ 13 C]alanine, 13 CO 2 and H 13 CO − 3was monitored with 1‐s temporal resolution. Hearts were also subjected to 10 min of global ischemia followed by reperfusion. Developed pressure, heart rate, oxygen consumption, [ATP], [phosphocreatine], and pH recovered within 3 min after the ischemic period. During the first 90 s of reperfusion, [1‐ 13 C]alanine and [1‐ 13 C]lactate appeared rapidly, demonstrating metabolism of pyruvate through two enzymes largely confined to the cytosol, alanine aminotransferase, and lactate dehydrogenase. 13 CO 2 and H 13 CO − 3were not detected. Late after ischemia and reperfusion, the products of pyruvate dehydrogenase, 13 CO 2 and H 13 CO − 3were easily detected. Using this multinuclear NMR approach, we established that during the first 90 s of reperfusion PDH flux is essentially zero and recovers within 20 min in reversibly‐injured myocardium. Magn Reson Med 60:1029–1036, 2008. © 2008 Wiley‐Liss, Inc.