¹H NMR and hyperpolarized ¹³C NMR assays of pyruvate-lactate: a comparative study.

Abstract

Pyruvate-lactate exchange is mediated by the enzyme lactate dehydrogenase (LDH) and is central to the altered energy metabolism in cancer cells. The measurement of exchange kinetics using hyperpolarized (13) C NMR has provided a biomarker of response to novel therapeutics. However, the observable signal is restricted to the exchanging hyperpolarized (13) C pools and the endogenous pools of (12) C-labelled metabolites are invisible in these measurements. In this study, we investigated an alternative in vitro (1) H NMR assay, using [3-(13) C]pyruvate, and compared the measured kinetics with a hyperpolarized (13) C NMR assay, using [1-(13) C]pyruvate, under the same conditions in human colorectal carcinoma SW1222 cells. The apparent forward reaction rate constants (kPL ) derived from the two assays showed no significant difference, and both assays had similar reproducibility (kPL  = 0.506 ± 0.054 and kPL  = 0.441 ± 0.090 nmol/s/10(6) cells; mean ± standard deviation; n = 3); (1) H, (13) C assays, respectively). The apparent backward reaction rate constant (kLP ) could only be measured with good reproducibility using the (1) H NMR assay (kLP  = 0.376 ± 0.091 nmol/s/10(6) cells; mean ± standard deviation; n = 3). The (1) H NMR assay has adequate sensitivity to measure real-time pyruvate-lactate exchange kinetics in vitro, offering a complementary and accessible assay of apparent LDH activity.

• Authors: Deborah K Hill, Yann Jamin, Matthew R Orton, Nicolas Tardif, Harold G Parkes, Simon P Robinson, Martin O Leach, Yuen-Li Chung, Thomas R Eykyn
• Journal: NMR in biomedicine (NMR Biomed) Vol. 26 Issue 10 Pg. 1321-1325 (Oct 2013) ISSN: 1099-1492 [Electronic] England
• PMID: 23712817 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 John Wiley & Sons, Ltd.

Chemical References

• Carbon Isotopes
• Protons
• Lactic Acid
• Pyruvic Acid
• L-Lactate Dehydrogenase

Topics

• Carbon Isotopes
• Cell Line, Tumor
• Humans
• L-Lactate Dehydrogenase (metabolism)
• Lactic Acid (metabolism)
• Magnetic Resonance Spectroscopy
• Protons
• Pyruvic Acid (metabolism)