Abstract
The 13C-fractional enrichments in the lactate and alanine methyl carbon positions were determined by 1H NMR spectroscopy of extracts of rat hearts perfused with various concentrations of [3-13C]pyruvate ± unlabeled glucose or acetate. In general, the 13C-fractional enrichment of the alanine methyl carbon pool paralleled the 13C-fractional enrichment of the acetyl-CoA which entered the TCA cycle (as determined by 13C-isotopomer analysis) while the 13C-fractional enrichment of the lactate methyl carbon was always significantly lower, consistent with a pool of lactate which does not mix with exogeneous [3-13C]pyruvate. This has also been examined in intact, perfused, KCl-arrested rat hearts supplied with [3-13C]pyruvate by proton double quantum motabolite specific spectroscopy (MSS). A comparison of MSS spectra of intact hearts with one pulse spectra of extracts of those same hearts indicates there is a sizeable non-enriched pool of lactate in the intact hearts which is not visible by NMR spectroscopy.
Original language | English (US) |
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Pages (from-to) | 247-250 |
Number of pages | 4 |
Journal | FEBS Letters |
Volume | 303 |
Issue number | 2-3 |
DOIs | |
State | Published - Jun 1 1992 |
Keywords
- C-fractional enrichment
- MSS spectroscopy
- NMR-invisible lactate
- Perfused heart
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology