Fish oil replacement in rainbow trout diets and total dietary PUFA content : II) Effects on fatty acid metabolism and in vivo fatty acid bioconversion

This study aimed to gain a better understanding of the metabolic fate of dietary fatty acids in rainbow trout, with a specific focus on the effect of varying total C18 PUFA level. Fish were fed a control fish oil based diet or one of five experimental fish oil deprived diets formulated with a consta...

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Bibliographic Details
Main Authors: Thanongsak Thanuthong, David Francis, Elizabeth Manickam, Shyamalie Sendadheera, David Cameron-Smith, Giovanni Turchini
Format: Other Non-Article Part of Journal/Newspaper
Language:unknown
Published: 2011
Subjects:
Zoology
alpha-linolenic acid (18:3n-3)
desaturase
elongase
fish oil replacement
linoleic acid (18:2n-6)
Science & Technology
Life Sciences & Biomedicine
Fisheries
Marine & Freshwater Biology
SALMON SALMO-SALAR
MACCULLOCHELLA-PEELII-PEELII
BETA-OXIDATION CAPACITY
VEGETABLE-OIL
MURRAY COD
OLIVE OIL
DOCOSAHEXAENOIC ACID
DELTA-6 DESATURASE
GENE-EXPRESSION
BALANCE METHOD
Salmo salar
Online Access:http://hdl.handle.net/10536/DRO/DU:30044373
https://figshare.com/articles/journal_contribution/Fish_oil_replacement_in_rainbow_trout_diets_and_total_dietary_PUFA_content_II_Effects_on_fatty_acid_metabolism_and_in_vivo_fatty_acid_bioconversion/20993371
Description
Summary:This study aimed to gain a better understanding of the metabolic fate of dietary fatty acids in rainbow trout, with a specific focus on the effect of varying total C18 PUFA level. Fish were fed a control fish oil based diet or one of five experimental fish oil deprived diets formulated with a constant 1/1 ratio of 18:3n-3/18:2n-6 and varying total C18 PUFA levels for a period of 7 weeks. The transcriptional changes of the Δ-6 desaturase and elongase enzymes in direct comparison to in vivo fatty acid bioconversion, estimated using the whole-body fatty acid balance method, were analysed. The main findings were that i) the efficiency of Δ-6 desaturase was negatively affected by C18 PUFA availability, but the total apparent in vivo enzyme activity was directly proportional to C18 PUFA substrate availability; ii) Δ-6 desaturase had a greater affinity towards n-3PUFA than n-6PUFA; iii) excessive C18 PUFA substrate availability could limit the availability of Δ-6 desaturase to act on C24 fatty acid; iv) the elimination of dietary n-3LC-PUFA (enzyme products) up-regulated the transcription rate of Δ-6 desaturase; but v) the total apparent in vivo enzyme activity was directly and positively affected by substrate availability, and not product presence/absence nor the extent of the enzyme transcription rate.

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