title: The effects of vitamin A, beta-carotene and canthaxanthin on vitamin A metabolism and immune responses in the chick.
abstract: Chicks were fed diets containing, 0, 0.85 and 350 mg/kg vitamin A and 1 g/kg beta-carotene or canthaxanthin from hatching. Carotene increased and canthaxanthin depressed plasma and hepatic vitamin A concentrations. High vitamin A levels decreased the concentration of both carotenoids. Neither carotene nor canthaxanthin affected intestinal carotene cleavage in vitro. T-lymphocyte proliferative responses were decreased at low vitamin A intakes and enhanced at the high vitamin A intake. Carotene and canthaxanthin fed with 0.85 mg/kg vitamin A had no effect on immune response and with 350 mg/kg vitamin A prevented the enhancement of the proliferative response. It is concluded that immune response in the chick is modulated by vitamin A; carotene and canthaxanthin effects are probably due to influences on vitamin A metabolism.
authors.affiliation: Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Sklan
authors.forename: T
authors.initials: T
authors.lastname: Yosefov
authors.forename: A
authors.initials: A
authors.lastname: Friedman
mesh_terms: D000818:Animals; D016644:Canthaxanthin; D002338:Carotenoids / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002645:Chickens; D004435:Eating; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D008297:Male; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014801:Vitamin A / Q000378:metabolism* / Q000494:pharmacology; D019207:beta Carotene
chemical_list: D019207:beta Carotene; D014801:Vitamin A; D002338:Carotenoids; D016644:Canthaxanthin