Carbon flux through citric acid cycle pathways in perfused heart by 13C NMR spectroscopy

FEBS Lett. 1987 Feb 9;212(1):58-62. doi: 10.1016/0014-5793(87)81556-9.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / metabolism*
  • Acetyl Coenzyme A / metabolism
  • Animals
  • Carbon / metabolism
  • Carbon Isotopes
  • Citric Acid Cycle*
  • Glutamates / metabolism
  • Glutamic Acid
  • Magnetic Resonance Spectroscopy
  • Male
  • Models, Biological
  • Myocardium / metabolism*
  • Rats
  • Rats, Inbred Strains


  • Acetates
  • Carbon Isotopes
  • Glutamates
  • Glutamic Acid
  • Acetyl Coenzyme A
  • Carbon