Oxidative decarboxylation of aspartate, alanine and glycine in developing rabbit brain

1. 1. Slices of immature rabbit brain were incubated in media utilizing as sole substrates, uniformly labeled with ¹⁴C: glucose, l-alamine, l-aspartate and glycine. In addition, slices were incubated with radioinert glucose combined with each of the labeled amino acids above. 2. 2. Only glucose supported O₂ uptake above the levels found with endogenous substrate. The addition of the amino acids to the glucose-containing media did not change the rate of O₂ uptake. 3. 3. The carbon skeletons of l-alanine and l-aspartate are oxidized to CO₂ by developing brain at all ages studied to a significant degree. The carbon skeleton of glycine is poorly oxidized to CO₂ at the same ages. The addition of glucose to each of the media containing l-aspartate and l-alanine leads to a great increase in amount of the amino acid carbon oxidized to CO₂ at all ages studied. The synergistic effect of increase of l-alanine oxidation when glucose is present has not previously been noted. 4. 4. The findings of these experiments suggest the availability of some amino acids as normal or emergency substrates of oxidative decarboxylation in the developing animal brain.