Glutamine affects glutamate metabolism in isolated rat kidney cortex mitochondria

The active state respiration of isolated rat kidney cortex mitochondria with 10 mM glutamate as single substrate is substantially increased by the addition of 10 mM glutamine. This increase in respiration was accompanied by a higher transamination rate and was found to be insensitive to the selective inhibition of either the transamination or the desamination pathway of glutamate oxidation. These data can be explained by an approximately 2-fold elevated intramitochondrial glutamate concentration observed in the additional presence of glutamine.