TY - JOUR
T1 - Assessing the sensitivity of Atlantic salmon (Salmo salar) to dietary endosulfan exposure using tissue biochemistry and histology
AU - Glover, Chris N.
AU - Petri, Dietrich
AU - Tollefsen, Knut Erik
AU - Jørum, Nanne
AU - Handy, Richard D.
AU - Berntssen, Marc H.G.
N1 - Funding Information:
The present project was jointly funded by the Norwegian Research Council (Project Number 16449/S40), the Norwegian Seafood Federation (FHL), and NIFES. The authors wish to thank Bjarte Sævareid and the staff at Lerang Research Station, Skretting ARC, for their excellent assistance in the feeding trial. Superb technical support was provided by Sonja Ylving, Åse Bakketun, Jacob Wessels and Eivind Farmen Finne. The authors are additionally grateful to Jan Vidar Jakobsen from EWOS Innovation and Ellinor Helland from Biomar for their contribution to the planning and execution of this study.
PY - 2007/10/15
Y1 - 2007/10/15
N2 - The incorporation of plant-based ingredients, and the possible carry-over of pesticides such as endosulfan, in fish feeds may present new toxicological challenges to aquacultural species. Biological responses of Atlantic salmon (Salmo salar) to a 35-day dietary endosulfan exposure at levels ranging from 4 to 710 μg kg-1 were assessed using tissue histology and biochemistry. Liver 7-ethoxyresorufin-O-deacetylase (EROD) activity was significantly elevated in the highest exposure group (710 μg kg-1) by day 35. Other hepatic indicators of stress impacts and responses (glutathione-S-transferase and glutathione peroxidase activities and hepatic α-tocopherol content) remained unchanged. Branchial Na+, K+-ATPase activity was significantly reduced at day 14 in the highest exposure group, but returned to control levels by day 35. Conversely, intestinal Na+, K+-ATPase activity was significantly inhibited at day 35, but again only at the highest exposure level. In contrast to the biochemical results, hepatic and intestinal histology revealed effects of exposure even at the lowest dose tested (4 μg kg-1). In the posterior intestine, pathology was characterised by vacuolation and fusion of villi, and in the most severe cases, loss of epithelial integrity in villi tips. In the liver the primary effects were glycogen depletion and lipidosis. These changes were typical of a generalised stress response. While histology endpoints may prove to be the most sensitive indicators of dietary endosulfan exposure, the organismal relevance of these structural changes must be considered in the absence of effects in other biomarkers at dietary levels less than 710 μg kg-1.
AB - The incorporation of plant-based ingredients, and the possible carry-over of pesticides such as endosulfan, in fish feeds may present new toxicological challenges to aquacultural species. Biological responses of Atlantic salmon (Salmo salar) to a 35-day dietary endosulfan exposure at levels ranging from 4 to 710 μg kg-1 were assessed using tissue histology and biochemistry. Liver 7-ethoxyresorufin-O-deacetylase (EROD) activity was significantly elevated in the highest exposure group (710 μg kg-1) by day 35. Other hepatic indicators of stress impacts and responses (glutathione-S-transferase and glutathione peroxidase activities and hepatic α-tocopherol content) remained unchanged. Branchial Na+, K+-ATPase activity was significantly reduced at day 14 in the highest exposure group, but returned to control levels by day 35. Conversely, intestinal Na+, K+-ATPase activity was significantly inhibited at day 35, but again only at the highest exposure level. In contrast to the biochemical results, hepatic and intestinal histology revealed effects of exposure even at the lowest dose tested (4 μg kg-1). In the posterior intestine, pathology was characterised by vacuolation and fusion of villi, and in the most severe cases, loss of epithelial integrity in villi tips. In the liver the primary effects were glycogen depletion and lipidosis. These changes were typical of a generalised stress response. While histology endpoints may prove to be the most sensitive indicators of dietary endosulfan exposure, the organismal relevance of these structural changes must be considered in the absence of effects in other biomarkers at dietary levels less than 710 μg kg-1.
KW - Dietary toxicity
KW - Feed legislation
KW - Histology
KW - Organochlorine pesticide
KW - Pathology
UR - http://www.scopus.com/inward/record.url?scp=34547917197&partnerID=8YFLogxK
U2 - 10.1016/j.aquatox.2007.06.013
DO - 10.1016/j.aquatox.2007.06.013
M3 - Journal Article
C2 - 17675176
AN - SCOPUS:34547917197
SN - 0166-445X
VL - 84
SP - 346
EP - 355
JO - Aquatic Toxicology
JF - Aquatic Toxicology
IS - 3
ER -