Metabolism following brain injury and treatment with exogenous fuels was studied. Injury-induced increases in lactate labeling via the pentose phosphate and pyruvate recycling pathways were not improved by fuel treatment. Sodium pyruvate improved neuronal oxidative metabolism. Injury-induced decreases in labeling via pyruvate carboxylase were improved by fuel treatment. Metabolic effects in astrocytes may contribute to improved cerebral glucose utilization following injury.