Uptake of orally administered beta-carotene by blood plasma, leukocytes, and lipoproteins in calves.
The uptake of beta-carotene by blood cells, plasma, and lipoproteins was studied in bull calves that were orally administered a single (Exp. 1; n = 18 Angus calves) or multiple (Exp. 2; n = 16 Holstein calves) doses of beta-carotene. Administration of beta-carotene increased plasma beta-carotene and the amount of beta-carotene associated with each lipoprotein fraction. Before beta-carotene treatment, the total amount of beta-carotene associated with the high-density lipoprotein (HDL) was three- to fourfold higher than the amount associated with low-density lipoprotein (LDL) and fivefold higher than the amount associated with very-low-density lipoprotein (VLDL). The relative increase in total beta-carotene associated with the lipoproteins was greater for LDL than for HDL or VLDL. Orally administered beta-carotene increased the uptake of beta-carotene by lymphocytes. Subcellular fractions of blood lymphocytes isolated from animals fed beta-carotene revealed that beta-carotene was taken up in significant amounts by the mitochondrial, nuclear, and microsomal fractions. The profile of beta-carotene uptake by these subcellular fractions did not mirror that observed in plasma. In contrast, beta-carotene was not detectable in blood neutrophils and erythrocytes in either beta-carotene-supplemented or unsupplemented calves. Treatment did not influence the concentrations of retinol or alpha-tocopherol in plasma, lipoproteins, lymphocytes, neutrophils, or erythrocytes. These data revealed the presence of beta-carotene in bovine lymphocyte subcellular fractions and suggest a possible physiological role of beta-carotene in these cells.
Chew
B P
BP
Department of Animal Sciences, Washington State University, Pullman 99164-6320.
Wong
T S
TS
Michal
J J
JJ
D000284:Administration, Oral; D000818:Animals; D002338:Carotenoids / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002417:Cattle / Q000097:blood / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D008074:Lipoproteins / Q000097:blood / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D008861:Microsomes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism; D014801:Vitamin A / Q000097:blood; D014810:Vitamin E / Q000097:blood; D019207:beta Carotene
D008074:Lipoproteins; D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids