title: Isolation of tryptophan as an inhibitor of ovalbumin permeation and analysis of its suppressive effect on oral sensitization.
abstract: Tryptophan was isolated from rat feces as an active compound against ovalbumin permeation in an in vitro Caco-2 cell model. Tryptophan dose-dependently inhibited ovalbumin permeation with accompanying increase in transepithelial electric resistance, and its inhibitory activity reached a plateau at 10 mM. Brown Norway rats were sensitized by intragastric administration of ovalbumin together with or without tryptophan. Antibody levels specific to ovalbumin in the sera and proliferative responses of spleen mononuclear cells to ovalbumin were significantly lower in rats administered ovalbumin plus tryptophan than those administered ovalbumin alone. These results suggest that tryptophan suppresses oral sensitization to ovalbumin, probably via suppression of ovalbumin absorption from the intestinal tract.
authors.affiliation: Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Watanabe
authors.forename: Kyoko
authors.initials: K
authors.lastname: Fukumoto
authors.forename: Eri
authors.initials: E
authors.lastname: Fukushi
authors.forename: Kei
authors.initials: K
authors.lastname: Sonoyama
authors.forename: Jun
authors.initials: J
authors.lastname: Kawabata
mesh_terms: D000284:Administration, Oral; D000485:Allergens / Q000494:pharmacology; D000818:Animals; D000906:Antibodies / Q000378:metabolism; D018938:Caco-2 Cells; D004305:Dose-Response Relationship, Drug; D005243:Feces; D005512:Food Hypersensitivity / Q000517:prevention & control; D006801:Humans; D007114:Immunization / Q000379:methods; D007422:Intestines / Q000187:drug effects; D008297:Male; D010047:Ovalbumin / Q000008:administration & dosage* / Q000037:antagonists & inhibitors / Q000276:immunology; D010539:Permeability; D051381:Rats; D011914:Rats, Inbred BN; D017208:Rats, Wistar; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D014364:Tryptophan / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000485:Allergens; D000906:Antibodies; D014364:Tryptophan; D010047:Ovalbumin