1H NMR observation of redox potential in liver.

1H NMR spectral editing techniques can select the distinct signals of lactate, pyruvate, beta-hydroxybutyrate, and acetoacetate and provide a unique way to monitor the biochemical processes in vivo. These metabolite levels reflect the near-equilibrium dehydrogenase activity and therefore the cellular redox state. The quantitative comparison between the 1H NMR and biochemical assay data is in excellent agreement. Lactate/pyruvate and beta-hydroxybutyrate/acetoacetate ratios, obtained from normalized 1H NMR spectra, respond directly to changes in the cytosolic and mitochondrial redox states. Because NMR is noninvasive, our results set the groundwork for implementing these techniques to observe tissue redox states in vivo.