The combined impact of plant-derived dietary ingredients and acute stress on the intestinal arachidonic acid cascade in Atlantic salmon (Salmo salar)

Abstract

Havforskningsinstituttets institusjonelle arkiv Brage IMR - Institutional repository of the Institute of Marine Research b r a g e i m rDette er forfatters siste versjon av den fagfellevurderte artikkelen, vanligvis omtalt som postprint. I Brage IMR er denne artikkelen ikke publisert med forlagets layout fordi forlaget ikke tillater dette. Du finner lenke til forlagets versjon i Brage-posten. Det anbefales at referanser til artikkelen hentes fra forlagets side. Ved lenking til artikkelen skal det lenkes til post i Brage IMR, ikke direkte til pdf-fil.This is the author's last version of the article after peer review and is not the publisher's version, usually referred to as postprint. You will find a link to the publisher's version in Brage IMR. It is recommended that you obtain the references from the publisher's site.Linking to the article should be to the Brage-record, not lear vacuoles and goblet cell hypertrophy and hyperplasia (4 -8) . 39Furthermore, substituting vegetable oils (VO) for fish oil (FO) 40 ingredients naturally decreases the high n-3:n-6 PUFA ratio of 41 a carnivorous fish's evolutionary consistent diet (9) . Alteration 42 of the dietary n-3:n-6 PUFA ratio can subsequently affect 43 the production of potent bioactive lipidic mediators of inflam-44 mation, termed as 'eicosanoids', which are synthesised from 45 C20 PUFA in cellular membranes (10) . 46In opposition to mammals, EPA (20 : 5n-3) predominates . Abbreviations: AA, arachidonic acid; ANF, anti-nutritional factor; COX-2, cyclo-oxygenase-2; cPLA 2 , cytosolic phospholipase A 2 ; DGLA, dihomo-g-linolenic acid; FM, fishmeal; FMFO, control diet of 100 % FM and 100 % fish oil; FO, fish oil; PLA 2 , phospholipase A 2 ; PP, plant protein; Tris, 2-amino-2-hydroxymethylpropane-1,3-diol; VO, vegetable oil; 40PP70VO, 40 % PP and 70 % VO replacement in diet; 80PP35VO, 80 % PP and 35 % VO replacement in diet; 80PP70VO, 80 % PP and 70 % VO replacement in diet.

Stress and expression of cyclooxygenases (cox1, cox2a, cox2b) and intestinal eicosanoids, in Atlantic salmon, Salmo salar L.

“…For cox2a and in particular cox2b however, we observed a very low expression in anterior enterocytes compared to posterior enterocytes. This agrees previous notions in Atlantic salmon cox2a (Oxley et al 2010), and may be linked to, in part, ion regulation and water absorption. In rats, PGE 2 will reduce water and chloride absorption (Hodeify and Kreydiyyeh 2007).…”

“…Whereas the expression was detected to be highest in the gill and at a similar lower level in muscle, midgut and hindgut, while the expression was subsequently lower in spleen and kidney and not detected in the liver. Previous studies have reported expressional differences between midgut and hindgut for cox2a (Oxley et al 2010), we could not detect any differences in expression of the cox genes between hindgut and midgut. However in our preparation we had used the whole intestine including muscle and enterocytes.…”

“…Frozen intestinal mucosa was homogenised and extracted for LCMS analysis as previously described (Oxley et al 2010) using PGB2-d4 as an internal standard. Extracts were subsequently purified by SPE (Masoodi and Nicolaou 2006) (Table 1).…”

“…This can for example enhance severity of inflammatory responses to external stimuli like vaccination (Gil-Martens 2010) which has become a necessity in intensive aquaculture. There is also some information that stress may affect the eicosanoid cascade, with many similarities to inflammatory processes (Oxley et al 2010). Increased knowledge of these mechanisms is essential for a future healthy aquaculture industry.…”

“…following stress, but not the eicosanoid content (Oxley et al 2010). It was hypothesized that this could be due to a delayed increase in eicosanoid production, which could help understand the long term effects of increased permeability seen in salmon intestines up to 48h post an acute stressor (Olsen et al 2005).…”