title: Peroral administration of specific antibody enhances carcinogen excretion.
abstract: Ingested carcinogens may exert effects directly on the gastrointestinal epithelium or after absorption and transport to other tissues. To determine the effect of anti-carcinogen antibody ingestion on dietary carcinogen excretion, a mixture of specific IgA or IgG and the model carcinogen 125I-N-2-(4-hydroxyphenyl-acetamido) fluorene (125I-pHP-AAF) was perorally administered to mice. These mice excreted more total and antibody-bound radiotracer in feces compared with controls given a similar mixture containing nonspecific antibody. In addition, urinary radiotracer excretion was reduced by 96% in specific-antibody dosed mice, indicating reduced gastrointestinal absorption of 125I-pHP-AAF. Reduced radiotracer absorption was also reflected by a 56% reduction in radiotracer content in tissues from mice receiving specific antibody. Other mice received peroral IgA before i.p. injection of 125I-PH-AAF. Specific antibody treatment consistently increased intraluminal radiotracer sequestration, as indicated by the level of total and antibody-bound radiotracer partitioning to aqueous fecal extracts. Similarly, when a mixture of 125I-pHP-AAF and IgG were injected directly into the small intestine, more radioactivity appeared in the feces of mice given specific antibody. High-performance liquid chromatography analysis of aqueous fecal extracts indicated that the majority of fecal radiotracer from specific-antibody dosed mice was unmetabolized parent compound. Thus, peroral administration of AAF-specific antibodies mixed with 125I-pHP-AAF decreased gastrointestinal absorption and increased fecal excretion of the radiotracer, suggesting a novel mechanism for protection against environmental carcinogens.
authors.affiliation: Department of Animal Science, University of Connecticut, CANR, Storrs 06269, USA.
authors.forename: M V
authors.initials: MV
authors.lastname: Rasmussen
authors.forename: L K
authors.initials: LK
authors.lastname: Silbart
mesh_terms: D015073:2-Acetylaminofluorene / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D000284:Administration, Oral; D000818:Animals; D000918:Antibody Specificity; D001682:Biological Availability; D002273:Carcinogens / Q000378:metabolism / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D005243:Feces / Q000737:chemistry*; D005260:Female; D005772:Gastrointestinal Transit; D007074:Immunoglobulin G / Q000276:immunology; D007274:Injections, Intraperitoneal; D007408:Intestinal Absorption; D007457:Iodine Radioisotopes; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D002273:Carcinogens; D007074:Immunoglobulin G; D007457:Iodine Radioisotopes; C117530:iodo-N-2-(4-hydroxyphenylacetamido)fluorene; D015073:2-Acetylaminofluorene