Metabolic Flux Analysis in Hepatic Systems

Metabolic flux analysis in hepatic systems entails the quantitative assessment of substrate utilisation and pathway activity within liver tissue. By integrating stable-isotope tracing with mathematical models, researchers can resolve dynamic flows through glycolysis, gluconeogenesis, the tricarboxylic acid (TCA) cycle and ancillary pathways. This approach illuminates how the liver maintains systemic energy balance, regulates blood glucose and orchestrates biosynthetic functions under varying physiological or pathological conditions. Recent advances in high-resolution mass spectrometry, magnetic resonance spectroscopy and computational algorithms have extended the depth of flux estimation from cell lines to intact ex vivo liver slices and whole-organ perfusions. Such developments have revealed species-specific differences in anaplerotic contributions, uncovered unexpected reversible reactions within the TCA cycle and enabled personalisation of metabolic phenotyping in human tissue. Ultimately, hepatic flux analysis informs the design of targeted therapies for metabolic disorders, refines nutritional interventions and enhances our fundamental understanding of organ-level metabolism.

Research from Nature Portfolio

Recent studies have deployed global 13C tracing combined with untargeted mass spectrometry to map fluxes in intact human liver tissue ex vivo. By incubating surgical specimens with uniformly labelled substrates, investigators reconstructed multiple pathways simultaneously, quantifying rates of gluconeogenesis, TCA cycle turnover and ancillary routes such as de novo creatine synthesis. This approach uncovered significant divergences between human and rodent hepatic metabolism, including enhanced branched-chain amino acid transamination and donor-specific glucose output linked to insulin sensitivity. The methodology offers a versatile platform for probing individual metabolic phenotypes and for evaluating pharmacological modulators of liver function in a setting that preserves tissue architecture and cellular interactions.

Metabolic Flux Analysis in Hepatic Systems publication trend

The graph below shows the total number of articles in metabolic flux analysis in hepatic systems across all publications each year (not limited to Nature Index journals).

Technical terms

Metabolic flux analysis: Quantitative determination of reaction rates through metabolic pathways using tracer data and computational models.

Isotope tracing: Use of stable-isotope-labelled substrates (e.g. 13C, 2H) to track atom flows through metabolic networks.

Anaplerosis: Replenishment of TCA cycle intermediates via pathways such as pyruvate carboxylation or amino acid transamination.

Isotopomer: Molecular species differing only in the position or number of stable-isotope labels.

Compartmental modelling: Mathematical framework that represents distinct cellular or organ compartments to estimate flux distributions from tracer kinetics.

References

1. Global 13C tracing and metabolic flux analysis of intact human liver tissue ex vivo. Nature Metabolism (2024).
2. Propionate Increases Hepatic Pyruvate Cycling and Anaplerosis and Alters Mitochondrial Metabolism*. Journal of Biological Chemistry (2016).
3. Reversibility of the mitochondrial isocitrate dehydrogenase reaction in the perfused rat liver. Evidence from isotopomer analysis of citric acid cycle intermediates.. Journal of Biological Chemistry (1994).
4. Multitissue 2H/13C flux analysis reveals reciprocal upregulation of renal gluconeogenesis in hepatic PEPCK-C–knockout mice. JCI Insight (2021).
5. Metabolic flux between organs measured by arteriovenous metabolite gradients. Experimental & Molecular Medicine (2022).