fig1

Figure 1. Energy metabolism in the healthy and aged heart. The red arrow facing up indicates an increase, and the arrow facing down indicates a decrease. PDK4: Pyruvate dehydrogenase kinase 4; PGC1α: PPAR gamma coactivator 1-alpha; PPARα: peroxisome proliferator-activated receptor α; PDH: pyruvate dehydrogenase; CPT1: carnitine palmitoyl transferase 1; BDH1: β-hydroxybutyrate dehydrogenase 1; LAT: L-type amino acid transporters; MPC: mitochondrial pyruvate carrier; MCT: monocarboxylate transporter; BCKDH: branched-chain alpha-keto acid dehydrogenase; NADH: nicotinamide adenine dinucleotide; SCOT: succinyl-CoA:3-ketoacid-CoA transferase. Created in BioRender. Seubert, J. (2026) https://BioRender.com/2piydk5.