ISSN:
1573-5168
Keywords:
vitamin E
;
tocopherol
;
Atlantic salmon
;
fish
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The purpose of this work was to study the turnover of a, γ andδtocopherol (TOH) in Atlantic salmon (Salmo salar, L.). Fish induplicate tanks were fed a diet containing 150 mg kg-1α-TOH and 100 mg kg-1 each of γ and δTOHadded as tocopheryl acetates. After fillet TOH concentrations had adjustedto the dietary supplementation levels, samples were taken from fish that hadbeen deprived of feed for 100 h, and from fish that had been fed regularlyuntil sampling. The retained levels of tocopherols in plasma correspondedgrossly with their biological activities, as found in experiments withmammals (α:γ:δ≈100: 20:3). The plasma concentrationsof α-, γ and δTOH amounted to 65, 44 and 15%,respectively, in unfed compared to fed fish. Very low density lipoprotein(VLDL), appeared to contain a greater fraction of plasma α-TOH than ofplasma δTOH. The mitochondrial fraction of liver, but not that of darkmuscle, was highly enriched in α-TOH, and less in γ andδTOH. The concentration ratios in liver and bile indicate thatδ, and to some extent, γTOH are excreted in the bile at a higherrate than α-TOH. The data fit the hypothesis that Atlantic salmonliver contains a tocopherol binding protein with higher affinity forα-TOH than for the other tocopherol homologues. This appears toprevent excretion of α-TOH in the bile, and stimulate incorporation ofα-TOH in VLDL for subsequent secretion into the blood stream. As aconsequence, α-TOH is retained in the body to a greater extent thanγ and α-TOH.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007798102002
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