13C-NMR analysis of alanine metabolism by isolated perfused livers from C3HeB/FeJ mice infected with African trypanosomes.

1. Isolated perfused livers from mice infected with Trypanosoma brucei rhodesiense formed substantially more [3-13C]-lactate from [3-13C]-alanine than livers from uninfected mice. Quantities formed by infected livers increased as infection progressed. 2. Infected livers produced more 13C-labeled glutamate and glutamine, with label scrambled between C-2 and C-3. Scrambling also produced [2,3-13C]-aspartate, [2-13C]-alanine and [2-13C]-lactate. Delayed appearance of label in C-4 of glutamate/glutamine in infected livers reflects significant endogenous stores of unlabeled acetyl CoA. 3. Although differences do exist in catabolism of [3-13C]-alanine by perfused livers from infected and control mice, trypanosomiasis does not cause permanent breakdown or blockage of hepatic alanine metabolism.