| 1. |
- de Gelder, Stefan, et al.
(författare)
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Transepithelial transfer of phenanthrene, but not of benzo[a]pyrene, is inhibited by fatty acids in the proximal intestine of rainbow trout (Oncorhynchus mykiss)
- 2018
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Ingår i: Comparative Biochemistry and Physiology Part C: Toxicology and Pharmacology. - : Elsevier BV. - 1532-0456 .- 1878-1659. ; 204, s. 97-105
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 Elsevier Inc. The inclusion of vegetable oils in aquafeeds introduces contaminating polycyclic aromatic hydrocarbons (PAHs) in salmonids. Since lipophilic PAHs solubilize in micelles composed of lipids, bile salts and fatty acids, dietary lipid composition can alter intestinal transepithelial PAH transfer. We studied the uptake of two PAHs, viz. benzo[a]pyrene (BaP) and phenanthrene (PHE), in rainbow trout (Oncorhynchus mykiss) intestine. We also investigated the effects of two fatty acids, viz. fish oil-derived eicosapentaenoic acid (EPA, 20:5n-3) and vegetable oil-derived oleic acid (18:1n-9) on intestinal uptake. Radiolabeled PAHs were solubilized in micelles composed of tritiated EPA and oleic acid, respectively, and administrated to intestinal segments mounted in Ussing chambers. In the absence of micelles, PHE accumulation was two times higher than BaP in the mucosal and serosal layers of proximal and distal intestine. Administration of PHE in micelles composed of oleic acid resulted in a 50% lower accumulation of PHE in the mucosal layers of the proximal intestine compared to EPA-composed micelles. Accumulation of EPA and oleic acid in the proximal intestinal mucosa correlated negatively with the transepithelial transfer of these fatty acids across the proximal intestinal epithelium. Transepithelial PHE transfer across the proximal intestine was reduced by 30% in co-exposure with EPA-composed micelles compared to 80% with oleic acid micelles. BaP was not transferred across the intestine. We conclude that the lipid composition of an aquafeed is an important determinant of PAH bioavailability. Therefore, lipid composition should be an important consideration in choosing vegetable oils as alternatives for fish oil in aquafeeds.
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| 2. |
- Haitina, Tatjana, 1981-
(författare)
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Function, Pharmacology, Evolution and Anatomical Localization of G Protein-Coupled Receptors and Solute Carriers
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The G protein-coupled receptors (GPCRs) and solute carriers (SLC) are two large families of membrane-bound proteins. The aim of this study was to characterize these two families in terms of evolution and function. The melanocortin (MC) receptors belong to the Rhodopsin family of GPCRs and we cloned the MC4 and MC5 receptors from the rainbow trout, MC3 and MC5 from the spiny dogfish and MCa and MCb from the river lamprey. Pharmacological characterization of the cloned MC receptors demonstrated higher affinity for adrenocorticotropic hormone (ACTH) compared to melanocyte stimulating hormone (MSH) peptides (alpha-, beta- and gamma-MSH). We performed expression analysis with reverse transcription PCR, which showed that the MC4 and MC5 receptors in the rainbow trout are expressed centrally as well as in peripheral tissues. The dogfish MC3 and MC5 receptors were expressed in the brain, while the lamprey MCa and MCb receptors were expressed in the periphery. An extensive tissue localization analysis was performed for the entire family of Adhesion GPCRs in the rat and mouse. Using quantitative real-time PCR (qRT-PCR) we discovered that the majority of GPCRs were expressed either specifically in the CNS or ubiquitously in the CNS and peripheral tissues. We identified all non-olfactory GPCRs in the dog and classified them into Adhesion, Frizzled, Glutamate, Rhodopsin and Secretin families. The dog GPCR repertoire seemed to be more similar to the human repertoire than to the repertoires in rodents. Solute carrier family 25 includes mitochondrial membrane transporters. Using bioinformatics techniques we identified 14 novel members of the SLC25 family, which now has 46 members. We identified orthologs of the novel SLC25 family members in yeast and performed expression analysis of 9 of them with qRT-PCR on a panel containing 30 central and peripheral tissues from the rat. To conclude, this study has expanded our knowledge of the repertoire of genes coding for membrane-bound proteins and provided information about their functional roles.
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| 3. |
- Vindas, Marco A., et al.
(författare)
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How do individuals cope with stress? : Behavioural, physiological and neuronal differences between proactive and reactive coping styles in fish
- 2017
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Ingår i: Journal of Experimental Biology. - : The Company of Biologists. - 0022-0949 .- 1477-9145. ; 220:8, s. 1524-1532
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Tidskriftsartikel (refereegranskat)abstract
- Despite the use of fish models to study human mental disorders and dysfunctions, knowledge of regional telencephalic responses in non-mammalian vertebrates expressing alternative stress coping styles is poor. As perception of salient stimuli associated with stress coping in mammals is mainly under forebrain limbic control, we tested region-specific forebrain neural (i.e. mRNA abundance and monoamine neurochemistry) and endocrine responses under basal and acute stress conditions for previously characterised proactive and reactive Atlantic salmon. Reactive fish showed a higher degree of the neurogenesis marker proliferating cell nuclear antigen (pcna) and dopamine activity under basal conditions in the proposed hippocampus homologue (Dl) and higher post-stress plasma cortisol levels. Proactive fish displayed higher post-stress serotonergic signalling (i.e. higher serotonergic activity and expression of the 5-HT1A receptor) in the proposed amygdala homologue (Dm), increased expression of the neuroplasticity marker brain-derived neurotropic factor (bdnf) in both Dl and the lateral septum homologue (Vv), as well as increased expression of the corticotropin releasing factor 1 (crf(1)) receptor in the Dl, in line with active coping neuro-profiles reported in the mammalian literature. We present novel evidence of proposed functional equivalences in the fish forebrain with mammalian limbic structures.
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