title: [Evaluation of N-acetyl-L-tryptophan in long-term intravenous administration in growing rats].
abstract: Utilization of N-acetyl-L-tryptophan as a source of L-tryptophan is tested in growing rats receiving total parenteral nutrition for twelve days. The three solutions tested are isonitrogenous and isocaloric. Solution 1 contains an adequate amount of L-tryptophan, while in solution 2 two thirds of the L-tryptophan are substituted by a corresponding amount of glycine. In solution 3, the entire L-tryptophan is replaced by N-acetyl-L-tryptophan. Weight gain and nitrogen balance are similar under the infusion with either the adequate amount of L-tryptophan or the N-acetyl-L-tryptophan. The solution 2 in which two thirds of the L-tryptophan are replaced by glycine yields significantly lower results for weight gain and nitrogen retention. The results indicate that tryptophan from N-acetyl-L-tryptophan, when given intravenously, is utilized by the rat for protein synthesis and growth as well as free tryptophan.
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D008134:Long-Term Care; D008297:Male; D010289:Parenteral Nutrition, Total; D051381:Rats; D011919:Rats, Inbred Strains; D014364:Tryptophan / Q000008:administration & dosage / Q000031:analogs & derivatives*
chemical_list: D000596:Amino Acids; C006392:N-acetyltryptophan; D014364:Tryptophan
vernacular_title: Die Verwertung von N-Acetyl-L-Tryptophan bei langfristiger intravenöser Verabreichung in wachsenden Ratten.