title: Detection of amino acids as possible promoters of bladder cancer in rats by measuring their enhancement of agglutination of bladder cells by concanavalin A.
abstract: The effects of amino acids on the enhanced agglutinability of bladder cells with concanavalin A induced by subcarcinogenic treatment with N-butyl-N-(4-hydroxybutyl)nitrosamine were examined. The amino acids examined were L-alanine, L-arginine, L-asparagine, L-aspartic acid, L-cysteine, L-glutamic acid, L-glutamine, L-glycine, DL- and L-histidine, L-hydroxyproline, L-isoleucine, D- and L-leucine, L-lysine, L-methionine, DL- and L-phenylalanine, L-proline, L-serine, L-threonine, DL-, D- and L-tryptophan, L-tyrosine and D- and L-valine. They were added to powdered diet at a concentration of 2.0%. L-Leucine, L-isoleucine, L-valine, DL- and D-tryptophan prolonged the period during which the bladder cells showed enhanced agglutinability with concanavalin A. Leupeptin, a protease inhibitor, and L-leucyl-L-leucine were also examined at a concentration of 0.1% because of their similar chemical structures, and were found to have the same effect. The tumor-promoting effects of DL-tryptophan and leupeptin have already been established by in vivo carcinogenesis experiments. The effects of L-leucine, L-isoleucine, L-valine, D-tryptophan and L-leucyl-L-leucine, detected by this short term assay, suggest that these compounds may also be promoters of bladder cancer in rats.
mesh_terms: D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D002085:Butylhydroxybutylnitrosamine; D002449:Cell Aggregation / Q000187:drug effects*; D003043:Cocarcinogenesis; D003208:Concanavalin A / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D001743:Urinary Bladder / Q000187:drug effects* / Q000473:pathology; D001749:Urinary Bladder Neoplasms / Q000139:chemically induced*
chemical_list: D000596:Amino Acids; D003208:Concanavalin A; D002085:Butylhydroxybutylnitrosamine