Karlos X. Moreno1, Scott Sabelhaus1, Matthew E. Merritt1, A Dean Sherry1, Craig R. Malloy1
The effect of [3-13C]pyruvate on [lactate] and [alanine] was studied in Langendorff-mode rat hearts. A 90 second perfusion with 2 mM [3-13C]pyruvate increased [lactate] and [alanine]. During the inhibition of aminotransferases by AOA, an increase in [alanine] was not observed, but, unexpectedly, [lactate] did not increase either. Lactate production was inhibited due to the lack of NADH replenishment from the malate-aspartate shuttle. These results support a reversal of the malate-aspartate shuttle to provide NADH for the production of lactate following a rapid increase in [pyruvate].