Brain metabolism of exogenous pyruvate.

摘要: Pyruvate given in large doses may be neuroprotective stroke, but it is not known to what degree the brain metabolizes pyruvate. Intravenous injection of [3-13C]pyruvate led dose-dependent labelling cerebral metabolites so that at 5 min after 18 mmoles [3-13C]pyruvate/kg (2 g sodium pyruvate/kg), approximately 20% glutamate and GABA were labelled, as could detected by 13C nuclear magnetic resonance spectrometry ex vivo. Pyruvate, 9 mmoles/kg, was equivalent glucose, a substrate for tricarboxylic acid (TCA) cycle activity. Inhibition glial TCA with fluoroacetate did affect formation [4-13C]glutamate or [2-13C]GABA from [3-13C]pyruvate, reduced [4-13C]glutamine 50%, indicating predominantly neuronal metabolism exogenous Extensive [3-13C]lactate [2-13C]pyruvate demonstrated reversible carboxylation pyruvate malate equilibration fumarate, presumably neurones, anaplerotic intermediates detected. Too rapid amounts seizure activity, respiratory arrest death. We conclude an excellent energy neurones vivo, care must taken avoid seizure-inducing effect doses.