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Updated: May 14, 2026

One-step Metabolomics: Carbohydrates, Organic and Amino Acids Quantified in a Single Procedure
Published on: June 25, 2010
Increased conversion of tryptophan to nicotinamide in rats by dietary valproate
Katsumi Shibata1, Rina Kondo, Mitsue Sano
1Department of Food Science and Nutrition, School of Human Cultures, The University of Shiga Prefecture, Hikone, Shiga, Japan. kshibata@shc.usp.ac.jp
Abstract:
Valproic acid (VPA) is a short-chained, branched fatty acid that is widely used in humans as an anticonvulsant and mood stabilizer, and has been reported to increase the liver NAD concentration. We investigated the effects of VPA on the conversion of tryptophan to nicotinamide. Rats were fed diets containing various amounts of VPA (0, 0.5, and 1.0% in the diets) for 14 d, 24-h urine samples were collected, and tryptophan and its catabolites were measured. We found that the conversion of tryptophan to nicotinamide was increased by feeding a diet containing VPA (p<0.01; 0% vs. 1.0% VPA). Of the intermediates formed during the conversion of tryptophan to nicotinamide, the tryptophan to 3-hydroxyanthranilic acid step was not affected by the administration of VPA, while such metabolites beyond quinolinic acid as nicotinamide and its catabolites were significantly increased (p<0.01; 0% vs. 1.0% VPA). This increase was dependent on the intake of VPA.
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