Dietary methylmercury and vegetable oil affects brain lipid composition in Atlantic salmon (Salmo salar L.)

Amlund, Heidi; Andreasen, Lise; Torstensen, Bente E.

doi:10.1016/j.fct.2011.12.041

Cited by 9 publications

(8 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar to Brodtkorb et al (1997), brain NL were composed predominantly of SAFA and when required, these could serve as energy source (De Roos, 1994) even if most energy is mobilized from glycogen in teleost brains (Soengas & Aldegunde, 2002). The high abundance of the monosaturated FA 18:1n-9 was reported in total lipids (Tocher & Harvie, 1988;Stoknes et al, 2004;Amlund et al, 2012) and the membrane lipids (Brodtkorb et al, 1997) of neural tissues (brain and eyes) of trout, salmon and marine fish species (Geurden et al, 1998). Farkas et al (2000) suggested that high levels of 18:1n-9 and 22:6n-3 in fish membranes are required for proper fusion and signal transduction rates in cold-adapted animals.…”

Section: Discussionmentioning

confidence: 99%

Polyunsaturated fatty acids in fish tissues more closely resemble algal than terrestrial diet sources

et al. 2020

View full text Add to dashboard Cite

The River Continuum Concept implies that consumers in headwater streams have greater dietary access to terrestrial basal resources, but recent studies have highlighted the dietary importance of high-quality algae. Algae provide consumers with physiologically important omega-3 (n-3) polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA). However, terrestrial plants and most benthic stream algae lack the long-chain (LC) n-3 PUFA docosahexaenoic acid (DHA, 22:6n-3), which is essential for neural development in fish and other vertebrates. We sampled subalpine streams to investigate how the PUFA composition of neural (brain and eyes), muscle, and liver tissues of freshwater fish is related to their potential diets (macroinvertebrates, epilithon, fresh and conditioned terrestrial leaves). The PUFA composition of consumers was more similar to epilithon than to terrestrial leaves. Storage lipids of eyes most closely resembled dietary PUFA (aquatic invertebrates and algae). However, DHA and arachidonic acid (ARA, 20:4n-6) were not directly available in the diet but abundant in organs. This implies that algal PUFA were selectively retained or were produced internally via enzymatic PUFA conversion by aquatic consumers. This field study demonstrates the nutritional importance of algal PUFA for neural organs in aquatic consumers of headwater regions.

show abstract

Section: Discussionmentioning

confidence: 99%

Polyunsaturated fatty acids in fish tissues more closely resemble algal than terrestrial diet sources

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Reduced DHA level in the brain and the retina have been seen in other animal models with severe n -3 FA deficiency ( 8 , 9 ) , including marine fish larva ( 10 , 11 ) , and has been linked to reduced neuromotor activity, learning skills and visual acuity in various animals. In Atlantic salmon, studies investigating FA composition of the brain and eye have mostly been carried out with dietary long-chain n -3 FA far above the expected requirement ( 12 , 13 ) . These studies observed that brain and retina DHA levels were highly conserved and not affected by diet, whereas tissue n -6 FA and to some extent EPA were more affected by diet.…”

mentioning

confidence: 99%

Long-term feeding of Atlantic salmon in seawater with low dietary long-chain n-3 fatty acids affects tissue status of the brain, retina and erythrocytes

Sissener¹,

Torstensen²,

Stubhaug

et al. 2016

Br J Nutr

View full text Add to dashboard Cite

In two long-term feeding trials in seawater, Atlantic salmon were fed EPA + DHA in graded levels, from 1·3 to 7·4 % of fatty acids (FA, 4-24 g/kg feed) combined with approximately 10 % 18 : 3n-3, at 6 and 12°C. Dietary EPA appeared to be sufficient in all diet groups, as no differences were seen in polar lipid tissue concentrations of either the brain, retina or erythrocytes. For DHA, a reduction in tissue levels was observed with low dietary supply. Effects on brain DHA at ≤1·4 % EPA + DHA of dietary FA and retina DHA at ≤2·7 % EPA + DHA of dietary FA were only observed in fish reared at 6°C, suggesting an effect of temperature, whereas tissue levels of n-6 FA increased as a response to increased dietary n-6 FA in both the brain and the retina at both temperatures. DHA levels in erythrocytes were affected by ≤2·7 % EPA + DHA at both temperatures. Therefore, DHA appears to be the limiting n-3 FA in diets where EPA and DHA are present in the ratios found in fishmeal and fish oil. To assess the physiological significance of FA differences in erythrocytes, the osmotic resistance was tested, but it did not vary between dietary groups. In conclusion, ≤2·7 % EPA + DHA of FA (≤9 g/kg feed) is not sufficient to maintain tissue DHA status in important tissues of Atlantic salmon throughout the seawater production cycle despite the presence of dietary 18 : 3n-3, and effects may be more severe at low water temperatures.Key words: EPA: DHA: Atlantic salmon: Requirements: Brain: Retina: Erythrocytes Stagnation, or even decline, in reduction fisheries (1) , combined with increased aquaculture production, necessitates the use of raw materials other than fishmeal (FM) and fish oil (FO) in feed for Atlantic salmon (Salmo salar L.). Decreased inclusion of FM and particularly FO means decreased concentration of the long-chain n-3 fatty acids (FA) EPA (20 : 5n-3) and DHA (22 : 6n-3), whereas alternative lipid sources used in commercial salmon feeds generally provide 18 : 3n-3 (2) . We have shown in two long-term trials during the seawater-stage of Atlantic salmon that low dietary EPA + DHA levels from 1·3 to 7·4 % of total FA (4-23 g/kg feed) did not affect mortality or cause severe essential FA (EFA) deficiency symptoms, but that levels >2·7 % of FA (9 g/kg feed) were required for optimal growth (G Rosenlund, BE Torstensen, I Stubhaug, N Usman and NH Sissener, et al., unpublished results). High retention efficiency of particularly DHA (>100 %) was seen in all diet groups, with retention increasing sharply to about 200 % at the lowest dietary concentrations (G Rosenlund, BE Torstensen, I Stubhaug, N Usman and NH Sissener, unpublished results), showing that the fish both efficiently store long-chain n-3 FA and also desaturate and elongate α-linolenic acid (LNA, 18 : 3n-3) to EPA and DHA. Such a capacity for elongation and desaturation has also been shown in salmon previously (3,4) , and a study on hepatocytes showed that n-3 FA were incorporated in lipid fractions to a higher extent than n-6 FA, while EFAdeficieny increased t...

show abstract

“…The proportions of 18:2 n-6, 20:3 n-6 and AA also decreased in the Hgcontaminated sea cucumber body wall (Telahigue et al, 2019) and tended to decrease in phospholipids of AA-enriched RTL-W1 cells after exposure to MeHg (Ferain et al, 2018). The reduction of AA from membrane phospholipids was also observed in phospholipids of Atlantic salmon brain after chronic dietary exposure to MeHg (5 mg/kg, 3 months) (Amlund et al, 2012), in primary rat neurons (Shanker et al, 2004) and astrocytes (Shanker et al, 2002), and in bovine pulmonary artery endothelial cell line (Mazerik et al, 2007;Sherwani et al, 2013) (5 mM MeHg, 0e120 min). Concerning the n-3 PUFA in phospholipids, Olsvik et al (2011) also showed a reduced content of EPA in Atlantic salmon brain after a 3-month exposure to MeHg (5 mg/kg) and Telahigue et al (2019) showed a lower proportion of EPA and a higher proportion of DHA after HgCl 2 contamination.…”

Section: Modulation Of Phospholipid Fatty Acid Composition By Mehgmentioning

confidence: 97%

Methylmercury displays pro-adipogenic properties in rainbow trout preadipocytes

et al. 2021

View full text Add to dashboard Cite

h i g h l i g h t s MeHg induced a dose-dependent accumulation of neutral lipids in preadipocytes. Accumulation of lipids persisted beyond the cellular exposure to MeHg. MeHg increased n-3 PUFA levels in lipid droplets and dropped AA levels in membranes. Expression of adipocyte-and lipid-specific genes was modulated by MeHg. Total mercury accumulated in cells was released when MeHg exposure stopped.

show abstract

Dietary methylmercury and vegetable oil affects brain lipid composition in Atlantic salmon (Salmo salar L.)

Cited by 9 publications

References 35 publications

Polyunsaturated fatty acids in fish tissues more closely resemble algal than terrestrial diet sources

Polyunsaturated fatty acids in fish tissues more closely resemble algal than terrestrial diet sources

Long-term feeding of Atlantic salmon in seawater with low dietary long-chain n-3 fatty acids affects tissue status of the brain, retina and erythrocytes

Methylmercury displays pro-adipogenic properties in rainbow trout preadipocytes

Contact Info

Product

Resources

About