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Direct observation of lactate and alanine by proton double quantum spectroscopy in rat hearts supplied with [3‐ 13 C]pyruvate
Author(s) -
Piyu Zhao,
A. Dean Sherry,
Craig R. Malloy,
Evelyn E. Babcock
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80530-t
Subject(s) - alanine , isotopomers , metabolite , spectroscopy , chemistry , nuclear magnetic resonance spectroscopy , carbon 13 , pyruvic acid , proton , citric acid cycle , metabolism , analytical chemistry (journal) , biochemistry , stereochemistry , amino acid , chromatography , organic chemistry , molecule , physics , quantum mechanics
The 13 C‐fractional enrichments in the lactate and alanine methyl carbon positions were determined by 1 H NMR spectroscopy of extracts of rat hearts perfused with various concentrations of [3‐ 13 C]pyruvate ± unlabeled glucose or acetate. In general, the 13 C‐fractional enrichment of the alanine methyl carbon pool paralleled the 13 C‐fractional enrichment of the acetyl‐CoA which entered the TCA cycle (as determined by 13 C‐isotopomer analysis) while the 13 C‐fractional enrichment of the lactate methyl carbon was always significantly lower, consistent with a pool of lactate which does not mix with exogeneous [3‐ 13 C]pyruvate. This has also been examined in intact, perfused, KCl‐arrested rat hearts supplied with [3‐ 13 C]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.