Probing carbohydrate metabolism using hyperpolarized C-labeled molecules.

Glycolysis is a fundamental metabolic process in all organisms. Anomalies in glucose metabolism are linked to various pathological conditions. In particular, elevated aerobic glycolysis is a characteristic feature of rapidly growing cells. Glycolysis and the closely related pentose phosphate pathway can be monitored in real time by hyperpolarized C-labeled metabolic substrates such as C-enriched, deuterated D-glucose derivatives, [2- C]-D-fructose, [2- C] dihydroxyacetone, [1- C]-D-glycerate, [1- C]-D-glucono-δ-lactone and [1- C] pyruvate in healthy and diseased tissues. Elevated glycolysis in tumors (the Warburg effect) was also successfully imaged using hyperpolarized [U- C , U- H ]-D-glucose, while the size of the preexisting lactate pool can be measured by C MRS and/or MRI with hyperpolarized [1- C]pyruvate. This review summarizes the application of various hyperpolarized C-labeled metabolites to the real-time monitoring of glycolysis and related metabolic processes in normal and diseased tissues.