A Novel 13C MRS-Based Marker of Pyruvate Cycling in Perfused Mouse Liver Using [2-13C] Pyruvate and 13C MRS<

Corin O'Dell Miller¹, Haiying Liu¹, Leslie Balogh², Jin Cao¹, Mike R. Tota³, Reshma Patel³

A 13C MRS approach was employed in perfused mouse livers metabolizing substrate levels of [2-13C] pyruvate to develop a novel ex-vivo marker of pyruvate recycling based on the 13C-enrichment in lactate. Inhibition of each of the pyruvate recycling pathways (PEPCK via 3-mercapto-picolinic acid, and Malic enzyme via tartronic acid) reduced this marker in liver extracts while simultaneous inhibition of each pathway further reduced this marker to levels near the LOQ. Real time data from whole perfused livers agreed with data from extracts of freeze-clamped livers indicating that this approach may be translatable to whole tissues and possibly in vivo.