MOUSE BLADDER CARCINOGENICITY OF CERTAIN TRYPTOPHAN METABOLITES AND OTHER AROMATIC NITROGEN COMPOUNDS SUSPENDED IN CHOLESTEROL.

Abstract

Summary The carcinogenicity of seven metabolites of the essential amino acid tryptophan and nine other nitrogen-containing aromatic compounds was studied by the individual suspension of these chemicals in cholesterol pellets and the surgical implantation of the pellets into the bladders of mice. Pellets consisting of the 8-methyl ether of xanthurenic acid, xanthurenic acid, 8-hydroxyquinaldic acid, 3-hydroxy-l-kynurenine, and 3-hydroxyanthranilic acid—all metabolites of tryptophan—and N-hydroxy-2-acetylaminofluorene, N-acetyl-2-naphthylhydroxylamine, and 2-naphthylhydroxylamine suspended in this medium induced a statistically greater number of bladder carcinomas than did cholesterol pellets alone. Pellets of 4,8-quinolinediol, kynurenic acid, 8-hydroxyquinoline-N-oxide, 2,8-quinolinediol, 2,6-quinolinediol, 2-naphthylacetamide, 2-nitronaphthalene, and 2-amino-1-naphthol hydrochloride mixed with cholesterol were not significantly more active than were the pellets of cholesterol. The significance of the data is discussed and related to the abnormalities of tryptophan metabolism observed in some patients with urinary bladder cancer.