| 1. |
- Birgersson, Lina, 1989, et al.
(författare)
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Thyroid function and immune status in perch (Perca fluviatilis) from lakes contaminated with PFASs or PCBs
- 2021
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier BV. - 0147-6513 .- 1090-2414. ; 222
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Tidskriftsartikel (refereegranskat)abstract
- The environment contains a multitude of man-made chemicals, some of which can act as endocrine disruptors (EDCs), while others can be immunotoxic. We evaluated thyroid disruption and immunotoxic effects in wild female perch (Perca fluviatilis) collected from two contaminated areas in Sweden; one site contaminated with perand polyfluoroalkyl substances (PFASs) and two sites contaminated with polychlorinated biphenyls (PCBs), with one reference site included for each area. The hepatic mRNA expression of thyroid receptors alpha and beta, and the thyroid hormone metabolising iodothyronine deiodinases (dio1, dio2 and dio3) were measured using real-time PCR, while the levels of thyroid hormone T3 in plasma was analysed using a radioimmunoassay. In addition, lymphocytes, granulocytes, and thrombocytes were counted microscopically. Our results showed lower levels of T3 as well as lower amounts of lymphocytes and granulocytes in perch collected from the PFAS-contaminated site compared to reference sites. In addition, expressions of mRNA coding for thyroid hormone metabolising enzymes (dio2 and dio3) and thyroid receptor alpha (thra) were significantly different in these fish compared to their reference site. For perch collected at the two PCB-contaminated sites, there were no significant differences in T3 levels or in expression levels of the thyroid-related genes, compared to the reference fish. Fish from one of the PCB-contaminated sites had higher levels of thrombocytes compared with both the second PCB lake and their reference lake; hence PCBs are unlikely to be the cause of this effect. The current study suggests that lifelong exposure to PFASs could affect both the thyroid hormone status and immune defence of perch in the wild.
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| 2. |
- Bresolin de Souza, Karine, et al.
(författare)
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Increased activity of lysozyme and complement system in Atlantic halibut exposed to elevated CO2 at six different temperatures.
- 2016
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Ingår i: Marine environmental research. - : Elsevier BV. - 1879-0291 .- 0141-1136. ; 122, s. 143-147
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Tidskriftsartikel (refereegranskat)abstract
- Ocean acidification and rising seawater temperature are environmental stressors resulting from the continuous increase of the atmospheric CO2 concentration due to anthropogenic activities. As a consequence, marine fish are expected to undergo conditions outside of their tolerance range, leading to physiological challenges with possible detrimental implications. Our research group has previously shown that exposure to elevated CO2 modulated the immune system of the Atlantic halibut. To further investigate this finding, we analysed non-specific immune components in blood plasma of Atlantic halibut (Hippoglossus hippoglossus) juveniles acclimated to six different temperatures (5, 10, 12, 14, 16 and 18°C), and to water pH of 8.0 (control) or 7.6 (predicted for year 2100) for three months. Plasma ions (K(+), Na(+), Ca(++), Cl(-)) and lactate concentrations were also measured. The analysis of plasma ions did not show any trends related to temperature or CO2 exposure, and the majority of the experimental fish were able to maintain ionic balance. The results show that both innate immune components (lysozyme and alternative complement system) had increased activities in response to elevated CO2, representing a CO2-related impact on the halibut's immune system. The increased activity of lysozyme and complement system is possibly part of the acclimatization process, and might be protective.
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| 3. |
- Frenzilli, Giada, et al.
(författare)
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Bisphenol A and Bisphenol S Induce Endocrine and Chromosomal Alterations in Brown Trout
- 2021
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Ingår i: Frontiers in endocrinology. - : Frontiers Media SA. - 1664-2392. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Bisphenol A is a widely used compound found in large amount of consumer products. As concerns have been raised about its toxicological and public health effect, the use of alternatives to bisphenol A are now increasing. Bisphenol S is one of the analogues being used as a replacement for bisphenol A despite the fact that little is known about the effects of bisphenol S on living organisms. In this study, we investigated the potential endocrine and genotoxic effects of bisphenol A and bisphenol S in juvenile brown trout (Salmo trutta). The fish were exposed to the compounds for either 2 weeks or 8 weeks via sustained-release cholesterol implants containing doses of 2 mg/kg fish or 20 mg/kg fish of the substances. The effects on the thyroid hormone levels and the estrogenic disrupting marker vitellogenin were evaluated, along with the genotoxic markers micronucleated cells and erythrocyte nuclear abnormalities. An increase in plasma vitellogenin was observed in fish exposed to the high dose of bisphenol A for 2 weeks. At this experimental time the level of the thyroid hormone triiodothyronine (T3) in plasma was elevated after bisphenol S exposure at the high concentration, and paralleled by an increase of micronucleated cells. Moreover, bisphenol A induced an increase of micronuclei frequency in fish erythrocytes after the exposure at the lowest dose tested. Taken together the results indicate that both bisphenol A and its alternative bisphenol S cause endocrine disrupting and genotoxic effects in brown trout, although suggesting two different mechanisms of damage underlying bisphenol A and bisphenol S activity.
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| 4. |
- Gräns, Albin, 1979, et al.
(författare)
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Aerobic scope fails to explain the detrimental effects on growth resulting from warming and elevated CO2 in Atlantic halibut
- 2014
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Ingår i: Journal of Experimental Biology. - : The Company of Biologists. - 0022-0949 .- 1477-9145. ; 217:5, s. 711-717
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Tidskriftsartikel (refereegranskat)abstract
- As a consequence of increasing atmospheric CO2, the world's oceans are becoming warmer and more acidic. Whilst the ecological effects of these changes are poorly understood, it has been suggested that fish performance including growth will be reduced mainly as a result of limitations in oxygen transport capacity. Contrary to the predictions given by the oxygen- and capacity-limited thermal tolerance hypothesis, we show that aerobic scope and cardiac performance of Atlantic halibut (Hippoglossus hippoglossus) increase following 14–16 weeks exposure to elevated temperatures and even more so in combination with CO2-acidified seawater. However, the increase does not translate into improved growth, demonstrating that oxygen uptake is not the limiting factor for growth performance at high temperatures. Instead, long-term exposure to CO2-acidified seawater reduces growth at temperatures that are frequently encountered by this species in nature, indicating that elevated atmospheric CO2 levels may have serious implications on fish populations in the future.
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| 5. |
- Hedén, Ida, 1984, et al.
(författare)
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Dietary replacement of fishmeal with marine proteins recovered from shrimp and herring process waters promising in Atlantic salmon aquaculture
- 2023
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Ingår i: Aquaculture. - 0044-8486. ; 574
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Tidskriftsartikel (refereegranskat)abstract
- There is a general agreement that fish meal (FM) and fish oil (FO) are valuable resources for aquafeed, but that the production cannot keep the same pace as the current growth of the aquaculture industry. Therefore, there is a need to find alternative sources for lipids and protein. This study examines the possibility of using proteins recovered from seafood industry side stream waters as a complement to FM in feed for Atlantic salmon. To recover the proteins, herring and shrimp process side streams waters were flocculated then treated with dissolved air flotation (DAF), which is considered a gentle technology. Shrimp steam water was used to obtain shrimp protein (SP) and herring salt brine to obtain herring protein (HP). The recovered semi-solid protein fraction was spray dried and formulated into experimental diets at inclusion levels of 1.9–10% (dw/dw). Two feeding trials were conducted to investigate; 1) the properties of different flocculants to recover SP from shrimp steam water, alginate (Alg; 1.9% inclusion), carrageenan (Carr; 2.0% inclusion) and a synthetic flocculant from Kemira (Kem; 3.8% inclusion). 2) total or partial replacement of FM with SP-Alg (10% and no FM) and HP-Alg (3% and 8% FM). For both feeding trials each diet was provided to triplicate tanks (n = 31 and 30/tank) of Atlantic salmon with a start weight of 193 g (duration 10 weeks) and 304 g (duration 7 weeks) respectively. All fish showed similar feed intake, feed conversion ratio (on tank basis) and weight gain. The inclusion of SP or HP as total or partial replacement of FM did neither influence adiposity of the fish, as measured by condition factor, nor heposomatic index (HSI). No negative effect of the alternative protein could be found through histological examination of the intestine. In feeding trial two, diets did not affect the adaptive immune indicators CD8α and MHC II. The SP-Alg diet did not affect intestinal barrier and transporting functions, assessed using Ussing-chamber technology. However, HP-Alg affected the trans-epithelial resistance, which indicate that the intestinal barrier function could be affected by low inclusions. We conclude that from a biological perspective, SP recovered from shrimp steaming waters using Alg and DAF technology represents a new marine biomass with potential as a replacement for FM in Atlantic salmon feed. To diversify the possibility of using flocculants to retrieve proteins we also suggest further investigation of the potential to use Carr in larger inclusions.
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| 6. |
- Hinchcliffe, James, 1992, et al.
(författare)
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Aquafeed ingredient production from herring (Clupea harengus) by-products using pH-shift processing: Effect from by-product combinations, protein solubilization-pH and centrifugation force
- 2019
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Ingår i: Animal Feed Science and Technology. - : Elsevier BV. - 0377-8401. ; 247, s. 273-284
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Tidskriftsartikel (refereegranskat)abstract
- There is a strong need in animal production for sustainable protein sources used in feed. The aim of the present study was to evaluate the potential of the pH-shift process as a method to concentrate proteins from complex bone-rich herring (Clupea harengus) by-products. By-product parts (frame, head, guts), protein solubilization pH (pH 2.8 or 11.3) and separation g-force (800 or 8000 g) were varied. The findings revealed that protein recovery yields of up to 60% were obtained and that higher protein yield was obtained from the alkaline than the acid process. By-product part and g-force had no significant impact on protein yield. Protein levels reached in the concentrates were 75–80 % (dw basis). Protein concentrates contained a similar amino acid profile as have been reported for fishmeal, with ~40% essential amino acids and up to 7.8% and 2.8% of lysine and methionine. Residual levels of LC n-3 PUFA as well as calcium, magnesium, potassium and phosphorous were also found in the produced protein concentrates which could be an added value. Acid produced concentrates were particularly high in calcium potassium and phosphorous. Provided a careful evaluation, the pH-shift process could become a successful alternative to classic fish meal production for increasing the use of fish by-products for production of protein ingredients for feed. © 2018 Elsevier B.V.
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| 10. |
- Kling, Peter, 1968, et al.
(författare)
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The role of GH in lipid homeostasis, energy utilization and partitioning in rainbow trout: interactions with ghrelin, leptin and insulin-like growth factor I
- 2012
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Ingår i: General and Comparative Endocrinology. - : Elsevier BV. - 0016-6480. ; 175:1, s. 153-162
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Tidskriftsartikel (refereegranskat)abstract
- The growth-promoting effects of in vivo growth hormone (GH) treatment were studied in relation to size and lipid content of energy stores including liver, mesentery, white muscle and belly flap in rainbow trout. In order to elucidate endocrine interactions and links to regulation of growth, adiposity and energy metabolism, plasma levels of GH, insulin-like growth factor I (IGF-I), leptin (Lep) and ghrelin, were assessed and correlated to growth and energy status. In addition tissue-specific expression of lepa1 mRNA was examined. Juvenile rainbow trout were implanted with sustained-release bovine GH implants and terminally sub-sampled at 1, 3 and 6 weeks. GH increased specific growth rate, reduced condition factor (CF) and increased feed conversion efficiency resulting in a redistribution of energy stores. Thus, GH decreased mesenteric (MSI) and liver somatic index (LSI). Lipid content of the belly flap increased following GH-treatment while liver and muscle lipid content decreased. Independent of GH substantial growth was accompanied by an increase in muscle lipids and a decrease in belly flap lipids. The data suggest that the belly flap may function as an energy buffering tissue during episodes of feeding and lean growth. Liver and muscle lipids were positively correlated to body weight, indicating a size-dependent change in adiposity. Hepatic lepa1 mRNA positively correlated to MSI and CF and its expression decreased following GH treatment, coinciding with decreased hepatic lipid content. Plasma Lep was positively correlated to MSI and belly flap lipid content, suggesting that Lep may communicate energy status. In summary, the observed GH tissue-specific effects on lipid metabolism in rainbow trout highlight the complex physiology of the energy reserves and their endocrine control.
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