title: Carbon flux through citric acid cycle pathways in perfused heart by 13C NMR spectroscopy.
abstract: Mathematical models of the TCA cycle derived previously for 14C tracer studies have been extended to 13C NMR to measure the 13C fractional enrichment of [2-13C]acetyl-CoA entering the cycle and the relative activities of the oxidative versus anaplerotic pathways. The analysis is based upon the steady-state enrichment of 13C into the glutamate carbons. Hearts perfused with [2-13C]acetate show low but significant activity of the anaplerotic pathways. Activation of two different anaplerotic pathways is demonstrated by addition of unlabeled propionate or pyruvate to hearts perfused with [2-13C]acetate. In each case, the amount of [2-13C]acetate being oxidized and the relative carbon flux through anaplerotic versus oxidative pathways are evaluated.
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000105:Acetyl Coenzyme A / Q000378:metabolism; D000818:Animals; D002244:Carbon / Q000378:metabolism; D002247:Carbon Isotopes; D002952:Citric Acid Cycle; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008954:Models, Biological; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000085:Acetates; D002247:Carbon Isotopes; D005971:Glutamates; D018698:Glutamic Acid; D000105:Acetyl Coenzyme A; D002244:Carbon