The metabolic fate of glutamine nitrogen in the perfused rat kidney.

The fate of glutamine amide and amino nitrogen was determined in the perfused rat kidney. There is a deficit of about 40% in the recovery of glutamine nitrogen and NH3 in the perfusion medium. After correction for the tissue conetent of glutamine, the remaining nitrogen was fully accounted for by small amounts of NH3, glutamate, aspartate and a compound that liberated glutamate on acid hydrolysis, probably 5-oxopyrrolidine-2-carboxylate (pyroglutamate). The latter accounted for 8% of the glutamine metabolized.