Arachidonic Acid and Eicosapentaenoic Acid Metabolism in Juvenile Atlantic Salmon as Affected by Water Temperature
Autor/a
Norambuena, Fernando
Morais, Sofia
Emery, James A.
Turchini, Giovanni M.
Fecha de publicación
2015-11-24ISSN
1932-6203
Resumen
Salmons raised in aquaculture farms around the world are increasingly subjected to suboptimal environmental conditions, such as high water temperatures during summer seasons. Aerobic scope increases and lipid metabolism changes are known plasticity responses of fish for a better acclimation to high water temperature. The present study aimed at investigating the effect of high water temperature on the regulation of fatty acid metabolism in juvenile Atlantic salmon fed different dietary ARA/EPA ratios (arachidonic acid, 20:4n-6/ eicosapentaenoic acid, 20:5n-3), with particular focus on apparent in vivo
enzyme activities and gene expression of lipid metabolism pathways. Three experimental diets were formulated to be identical, except for the ratio EPA/ARA, and fed to triplicate groups of Atlantic salmon (Salmo salar) kept either at 10°C or 20°C. Results showed that fatty acid metabolic utilisation, and likely also their dietary requirements for optimal performance, can be affected by changes in their relative levels and by environmental temperature in Atlantic salmon. Thus, the increase in temperature, independently from dietary treatment, had a significant effect on the β-oxidation of a fatty acid including EPA, as
observed by the apparent in vivo enzyme activity and mRNA expression of pparα -transcription factor in lipid metabolism, including β-oxidation genes- and cpt1 -key enzyme responsible for the movement of LC-PUFA from the cytosol into the mitochondria for β-oxidation-, were both increased at the higher water temperature. An interesting interaction was observed in the transcription and in vivo enzyme activity of Δ5fad–time-limiting enzyme in the biosynthesis pathway of EPA and ARA. Such, at lower temperature, the highest mRNA expression and enzyme activity was recorded in fish with limited supply of dietary EPA, whereas at higher temperature these were recorded in fish with limited ARA supply. In consideration that fish at higher water temperature recorded a significantly increased feed intake, these results clearly suggested that at high, sub-optimal water temperature, fish metabolism attempted to increment its overall ARA status -the most bioactive LC-PUFA participating in the inflammatory response- by modulating the metabolic fate of dietary ARA (expressed as % of net intake), reducing its β-oxidation and favouring synthesis and deposition. This correlates also with results from other recent studies showing that both
immune- and stress- responses in fish are up regulated in fish held at high temperatures. This is a novel and fundamental information that warrants industry and scientific attention, in consideration of the imminent increase in water temperatures, continuous expansion of aquaculture operations, resources utilisation in aquafeed and much needed seasonal/adaptive nutritional strategies.
Tipo de documento
Artículo
Versión del documento
Versión publicada
Lengua
English
Materias (CDU)
639 - Caza. Pesca. Piscicultura
Páginas
25
Publicado por
Public Library of Science
Publicado en
PLoS ONE
Citación
Norambuena, Fernando, Sofia Morais, James A. Emery, and Giovanni M. Turchini. 2015. "Arachidonic Acid And Eicosapentaenoic Acid Metabolism In Juvenile Atlantic Salmon As Affected By Water Temperature". PLOS ONE 10 (11): e0143622. doi:10.1371/journal.pone.0143622.
Número del acuerdo de la subvención
EC/FP7-PEOPLE/274184/EU/Gastrointestinal and neuropeptides regulating food intake in fish in response to dietary lipid composition/GASTRONEUROPEP
Program
Aqüicultura
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