Synthesis and Metabolism of Tritium-Labeled DL-Kynurenine.

Abstract

DL-Kynurenine was labeled with tritium by the Wilzbach procedure. Intraperitoneal injection of tritium-labeled DL-kynurenine into rats was followed by the excretion of labeled quinolinic acid and N1-methyl -nicotinamide in the urine. The evidence is definite that kynurenine can serve as a precursor of quinolinic acid and N -methylnicotinamide. During 24 hours after injection of 1 mg of labeled DL-kynurenine, 6.86% was excreted as unchanged labeled kynurenine.