title: The effect of dietary lipid composition on the intestinal uptake and tissue distribution of benzo[a]pyrene and phenanthrene in Atlantic salmon (Salmo salar).
abstract: Uptake of polycyclic aromatic hydrocarbons (PAHs) across the intestine is suggested to occur in association with dietary lipids. Partial replacement of fish ingredients by vegetable ingredients in aquafeeds has led to increased levels of PAHs in marine farmed fish. We therefore investigated, intestinal uptake, tissue distribution and PAH metabolism after a single dose of (14)C-benzo[a]pyrene (BaP) or (14)C-phenanthrene (PHE) given to Atlantic salmon (Salmo salar) acclimatized to a fish oil or vegetable oil based diet. Both BaP and PHE were absorbed along the intestine. Fish oil based feed increased BaP concentration in the pyloric caeca and that of PHE in the proximal intestine. In contrast, vegetable oil increased BaP concentrations in the distal intestine. Extraction of whole body autoradiograms removed PHE-associated radiolabeling almost completely from the intestinal mucosa, but not BaP-associated radiolabeling, indicating the presence of BaP metabolites bound to cellular macromolecules. This observation correlates with the increased cyp1a expression in the proximal intestine, distal intestine and liver in the BaP exposed group. Furthermore, BaP-induced cyp1a expression was higher in the distal intestine of salmon fed fish oil compared to the vegetable oil fed group. PHE had no significant effect on cyp1a expression in any of these tissues. We conclude that dietary lipid composition affects intestinal PAH uptake. Fish oil based feed increased intestinal PAH concentrations probably due to an enhanced solubility in micelles composed of fish oil fatty acids. Increased BaP accumulation in the distal intestine of vegetable oil fed fish seems to be associated with a reduced Cyp1a-mediated BaP metabolism.
authors.affiliation: Radboud University, Institute for Water and Wetland Research, Department of Animal Ecology and Physiology, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands; National Institute of Nutrition and Seafood Research, P.O. Box 2029 Nordnes, 5817 Bergen, Norway. Electronic address: s.degelder@science.ru.nl.
authors.forename: Stefan
authors.initials: S
authors.lastname: de Gelder
authors.affiliation: University of Life Science (NMBU), Faculty of Veterinary Medicine and Biosciences, Department of Food Safety and Infection Biology, P.O. Box 8146 Dep., 0033 Oslo, Norway.
authors.forename: Marit J
authors.initials: MJ
authors.lastname: Bakke
authors.affiliation: Radboud University, Institute for Water and Wetland Research, Department of Animal Ecology and Physiology, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Vos
authors.affiliation: National Institute of Nutrition and Seafood Research, P.O. Box 2029 Nordnes, 5817 Bergen, Norway.
authors.forename: Josef D
authors.initials: JD
authors.lastname: Rasinger
authors.affiliation: University of Life Science (NMBU), Faculty of Veterinary Medicine and Biosciences, Department of Food Safety and Infection Biology, P.O. Box 8146 Dep., 0033 Oslo, Norway.
authors.forename: Kristian
authors.initials: K
authors.lastname: Ingebrigtsen
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway.
authors.forename: Merete
authors.initials: M
authors.lastname: Grung
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo, Norway.
authors.forename: Anders
authors.initials: A
authors.lastname: Ruus
authors.affiliation: Radboud University, Institute for Water and Wetland Research, Department of Animal Ecology and Physiology, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands.
authors.forename: Gert
authors.initials: G
authors.lastname: Flik
authors.affiliation: Radboud University, Institute for Water and Wetland Research, Department of Animal Ecology and Physiology, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands.
authors.forename: Peter H M
authors.initials: PHM
authors.lastname: Klaren
authors.affiliation: National Institute of Nutrition and Seafood Research, P.O. Box 2029 Nordnes, 5817 Bergen, Norway.
authors.forename: Marc H G
authors.initials: MHG
authors.lastname: Berntssen
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001564:Benzo(a)pyrene / Q000378:metabolism* / Q000633:toxicity; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis / Q000235:genetics; D065693:Cytochrome P-450 Enzyme Inducers / Q000378:metabolism / Q000633:toxicity; D004041:Dietary Fats / Q000008:administration & dosage* / Q000378:metabolism; D004790:Enzyme Induction; D005395:Fish Oils / Q000008:administration & dosage* / Q000378:metabolism; D065570:Gastric Absorption; D007408:Intestinal Absorption / Q000187:drug effects; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects; D008099:Liver / Q000378:metabolism; D010616:Phenanthrenes / Q000378:metabolism* / Q000633:toxicity; D010938:Plant Oils / Q000008:administration & dosage* / Q000378:metabolism; D020317:Salmo salar / Q000378:metabolism*; D012995:Solubility; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D065693:Cytochrome P-450 Enzyme Inducers; D004041:Dietary Fats; D005395:Fish Oils; D010616:Phenanthrenes; D010938:Plant Oils; D001564:Benzo(a)pyrene; C031181:phenanthrene; D019363:Cytochrome P-450 CYP1A1
keywords: Aquafeeds; Fish oil; Intestinal absorption; PAH metabolites; Polycyclic aromatic hydrocarbons (PAH); Vegetable oil