Figure 2.

Metabolic pathways interrogated according to ¹³C labelled position, blue C2 position, red C1 position. (A) [1-¹³C]pyruvate spectrum showing conversion to lactate, pyruvate hydrate, alanine and bicarbonate and (B) Example spectra acquired in the first 60s following [2-¹³C]pyruvate infusion in the in vivo rat heart. [2-¹³C]pyruvate is observed at 207.8 ppm. Peaks from (1) [5-¹³C]glutamate, (2) [1-¹³C]citrate, (3) [1-¹³C]acetylcarnitine, (4) [1-¹³C]pyruvate, (5) [2-¹³C]lactate & (6) [2-¹³C]alanine can be seen.