Fig. 4

Metabolic pathways with compounds that can be used as molecular imaging probes for HP MRI. A wide variety of metabolic pathways have already been visualized or have the potential to be visualized using hyperpolarization technology that can be applied to different pathological states of the cell including cardiovascular disease and a large variety of cancers. 1. Metabolism of C1 (red dots) in pyruvate. The asterisks on selected compounds represent enrichment of ¹³C in the second pass of pyruvate in TCA cycle. 2. Metabolism of C1 (brown dots) in DHA using a pool of NADPH derived from the pentose phosphate pathway. 3. Metabolism of C1 (blue dots) and C5 (green dots) of glutamine. 4. Metabolism of C1 and C4 (purple dots) of fumarate unrelated to TCA metabolites. 5. Metabolism of extracellular bicarbonate (gray dots). MTC1 monocarboxylate transporter 1, MTC4 monocarboxylate transporter 4, System ASC amino acid transporter, GLUTs glucose transporters, DCT dicarboxylate transporter, DHAR dehydroascorbate reductase, GR glutathione reductase, GSH glutathione, GSSG glutathione disulfide, LDH lactate dehydrogenase, ALT alanine transaminase, CA carbonic anhydrase, PC pyruvate carboxylase, PDH pyruvate dehydrogenase, CS citrate synthase, GLS glutaminase, GLDH glutamate dehydrogenase, IDH isocitrate dehydrogenase, OGDC oxoglutarate dehydrogenase complex, SCS succinyl CoA synthetase, SQR succinate dehydrogenase, FH fumarate hydratase, MDH malate dehydrogenase, FUM fumarase. Cofactors have been omitted for brevity