title: Microorganisms in the gastrointestinal tract of the rat prevent absorption of the mutagen-carcinogen 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole.
abstract: The extent to which lactic acid bacteria, intestinal bacteria, and yeast from the gastrointestinal tract of rats suppress the absorption of 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole (Trp-P-1) was investigated. Trp-P-1 was absorbed from the small intestine very rapidly, but in the stomach it was slowly absorbed, requiring 1 or 2 h after administration. When mixtures of Trp-P-1 and freeze-dried microorganisms were administered to rats for 1 h, the amounts of Trp-P-1 absorbed from the small intestine were significantly reduced, and the levels of Trp-P-1 in blood decreased by 40.4-64.7% compared with a control in which only Trp-P-1 was administered. There were no significant differences between the organisms used. In vitro, freeze-dried cells of the strains tested bound 51-97% of Trp-P-1. The Trp-P-1 bound to cells was effectively extracted by aqueous methanol, ethanol, ammonia (50 g/L), and solutions of MgCl2 and CaCl2 (100 mM/mL), but little was extracted by water and solutions of KCl, NaCl, and buffers at various pH values.
authors.affiliation: Department of Biology, York University, Toronto, ON, Canada.
authors.forename: X B
authors.initials: XB
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Ohta
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001419:Bacteria / Q000378:metabolism; D002243:Carbolines / Q000097:blood / Q000302:isolation & purification / Q000378:metabolism*; D002273:Carcinogens / Q000378:metabolism*; D004064:Digestive System / Q000378:metabolism / Q000382:microbiology*; D007408:Intestinal Absorption; D007421:Intestine, Small / Q000378:metabolism*; D008099:Liver / Q000737:chemistry; D008297:Male; D009153:Mutagens / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach / Q000737:chemistry; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D002243:Carbolines; D002273:Carcinogens; D009153:Mutagens; C019132:3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole