NMR indirect detection of glutamate to measure citric acid cycle flux in the isolated perfused mouse heart.
(13)C-edited proton nuclear magnetic resonance (NMR) spectroscopy was used to follow enrichment of glutamate C3 and C4 with a temporal resolution of approximately 20 s in mouse hearts perfused with (13)C-enriched substrates. A fit of the NMR data to a kinetic model of the tricarboxylic acid (TCA) cycle and related exchange reactions yielded TCA cycle (V(tca)) and exchange (V(x)) fluxes between alpha-ketoglutarate and glutamate. These fluxes were substrate-dependent and decreased in the order acetate (V(tca)=14.1 micromol g(-1) min(-1); V(x)=26.5 micromol g(-1) min(-1))>octanoate (V(tca)=6.0 micromol g(-1) min(-1); V(x)=16.1 micromol g(-1) min(-1))>lactate (V(tca)=4.2 micromol g(-1) min(-1); V(x)=6.3 micromol g(-1) min(-1)).
Burgess
S C
SC
Department of Chemistry, University of Texas at Dallas, USA.
Babcock
E E
EE
Jeffrey
F M
FM
Sherry
A D
AD
Malloy
C R
CR
D000818:Animals; D002952:Citric Acid Cycle / Q000502:physiology*; D005260:Female; D018698:Glutamic Acid / Q000032:analysis* / Q000378:metabolism; D066298:In Vitro Techniques; D007656:Ketoglutaric Acids / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D051379:Mice; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption; D010477:Perfusion; D012680:Sensitivity and Specificity
D007656:Ketoglutaric Acids; D018698:Glutamic Acid