Eun-Hee Leea, Moonkoo Kima,b, Young-Sun Moona, Un Hyuk Yima,b, Sung Yong Haa,Chang-Bum Jeongc, Jae-Seong Leec, Jee-Hyun Junga,b,*
aOil & POPs Research Group, Korea Institute of Ocean Science & Technology, Geoje, 53201, Republic of Korea
bDepartment of Marine Environmental Science, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea
cDepartment of Biological Science, College of Science, Sungkyunkwan University, Suwon, 16419, Republic of Kore
*Corresponding author
Abstract
To demonstrate the effects of weathered crude oil residue on the immune systems of resident fish, we measured the changes in toxic chemical concentrations, apoptosis, phagocytosis, metabolism, immune-related gene expression, and cell cycle arrest in livers or kidneys for up to 96h after the weathered Iranian heavy crude oil (WIHCO) exposure by oral gavage in juvenile rockfish Sebastes schlegeli. Parent polyaromatic hydrocarbons (PAHs) in livers increased up to 5590ng/g after 6h exposure and then declined rapidly within 24h. Hepato-detoxification and immune-related gene expression were also significantly increased (P<0.05) after 6h exposure and then declined rapidly within 24h. However, biliary PAH metabolites and EROD activity remained elevated throughout the test period. Flow cytometry analysis also indicated sustained apoptosis and cell cycle arrests with reduced phagocytic activity for 96h. Taken together, these results demonstrate rapid declination of the parent PAHs, whereas PAH metabolites remained much longer in tissues with prolonged suppression of immunity in molecular and cellular level, suggesting that weathered crude oil residue is likely linked to the high incidence of immune dysfunction in residential rockfish in oil spill area.
Keywords : Oil spill, Immune system, PAHs, Apoptosis, Flow cytometry, Phagocytosis