title: Evaluation of the preruminant calf as a model for the study of human carotenoid metabolism.
abstract: This study evaluated the preruminant calf as an animal model for the study of human carotenoid metabolism. Fifteen newborn male Holstein calves were fed a carotenoid-free milk replacer diet to maintain them in the preruminant state. After a 7-d adjustment period, three calves were killed and 12 calves received a single oral dose (20 mg) of beta-carotene in the form of water-soluble beadlets. Blood samples were collected periodically and samples of various tissues were collected when the calves were killed. Three animals each were killed by exsanguination at 1, 3, 6 and 11 d post-dosing. Serum beta-carotene concentrations peaked between 12 and 30 h post-dosing and declined slowly afterwards. Serum data were fitted to a two-compartment model and yielded an elimination constant (k2) that was similar to reported human values. Adrenal tissue showed significant concentrations of beta-carotene by 24 h post-dosing, and levels were still elevated at 264 h. Liver, spleen and lung beta-carotene concentrations were significantly elevated by 24 h and rapidly declined thereafter. Adipose and kidney peak beta-carotene concentrations were observed at 72 and 144 h, respectively. Heart and muscle did not display significant changes in beta-carotene concentrations. The preruminant calf shows promise as an animal model for the study of absorption and metabolism of carotenoids by humans.
authors.affiliation: Division of Nutritional Sciences, University of Illinois, Urbana 61801.
authors.forename: C L
authors.initials: CL
authors.lastname: Poor
authors.forename: T L
authors.initials: TL
authors.lastname: Bierer
authors.forename: N R
authors.initials: NR
authors.lastname: Merchen
authors.forename: G C
authors.initials: GC
authors.lastname: Fahey
authors.forename: M R
authors.initials: MR
authors.lastname: Murphy
authors.forename: J W
authors.initials: JW
authors.lastname: Erdman
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000284:Administration, Oral; D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D002338:Carotenoids / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002417:Cattle / Q000378:metabolism*; D005069:Evaluation Studies as Topic; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D013154:Spleen / Q000378:metabolism; D014018:Tissue Distribution; D014801:Vitamin A / Q000032:analysis; D019207:beta Carotene
chemical_list: D019207:beta Carotene; D014801:Vitamin A; D002338:Carotenoids