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In vivo 13 C saturation transfer effect of the lactate dehydrogenase reaction
Author(s) -
Xu Su,
Yang Jehoon,
Shen Jun
Publication year - 2007
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.21137
Subject(s) - in vivo , lactate dehydrogenase , magnetization transfer , chemistry , nuclear magnetic resonance , pyruvic acid , reaction rate constant , pyruvate dehydrogenase complex , kinetics , biochemistry , magnetic resonance imaging , biology , enzyme , medicine , physics , microbiology and biotechnology , radiology , quantum mechanics
Lactate dehydrogenase (LDH, EC 1.1.1.27) catalyzes an exchange reaction between pyruvate and lactate. It is demonstrated here that this reaction is sufficiently fast to cause a significant magnetization (saturation) transfer effect when the 13 C resonance of pyruvate is saturated by a continuous‐wave (CW) RF pulse. Infusion of [2‐ 13 C]glucose was used to allow labeling of pyruvate C2 at 207.9 ppm to determine the pseudo first‐order rate constant of the unidirectional lactate → pyruvate flux in vivo. During systemic administration of GABA A receptor antagonist bicuculline, this pseudo first‐order rate constant was determined to be 0.08 ± 0.01 s −1 (mean ± SD, N = 4) in halothane‐anesthetized adult rat brains. In 9L and C6 rat glioma models, the 13 C saturation transfer effect of the LDH reaction was also detected in vivo. Our results demonstrate that the 13 C magnetization transfer effect of the LDH reaction may be useful as a novel marker for utilizing noninvasive in vivo MRS to study many physiological and pathological conditions, such as cancer. Magn Reson Med 57:258–264, 2007. © 2007 Wiley‐Liss, Inc.