title: Induction and localization of hepatic CYP4501A in flounder and rainbow trout exposed to benzo[a]pyrene.
abstract: The hepatic detoxification system in Baltic flounder and rainbow trout was characterized under experimental conditions. Fish were exposed to benzo[a]pyrene (BaP, 10 and 50mg/kg, ip) or vehicle for 2, 5, and 10 days (in rainbow trout also for 20 days) and then sacrificed. Control fish were sampled at days 0 and 10 (flounder) or day 20 (rainbow trout). The hepatic distribution of CYP1A was analyzed immunohistochemically and microsomal ethoxyresorufin O-deethylase activity was determined spectrophotometrically. The kinetics of the CYP1A responses (EROD) was similar in both species, while a species-specific difference in the magnitude of the response was observed. CYP1A was demonstrated in the hepatocytes in both fish species 2 days after BaP administration and throughout the experiment. In rainbow trout a CYP1A response in the vascular endothelium of liver parenchyma was detected 2 days postadministration, while the corresponding reaction in flounder was seen 5 days postadministration. Thus, our results confirm previous reports that the CYP1A response is species specific. Furthermore, the induction of hepatic CYP1A in Baltic flounder reflects pathophysiological effects induced by polycyclic aromatic hydrocarbon compounds and, consequently, is a parameter useful when monitoring the anthropogenic effects on the Baltic Sea environment.
authors.affiliation: Laboratory of Aquatic Pathobiology, Department of Biology, Abo Akademi University, Artillerigatan 6, FIN-20520 Abo, Finland. chira.malmstrom@schering.fi
authors.forename: C M
authors.initials: CM
authors.lastname: Malmström
authors.forename: K
authors.initials: K
authors.lastname: Koponen
authors.forename: P
authors.initials: P
authors.lastname: Lindström-Seppä
authors.forename: G
authors.initials: G
authors.lastname: Bylund
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D019363:Cytochrome P-450 CYP1A1 / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D005387:Finland; D005432:Flounder / Q000378:metabolism*; D007150:Immunohistochemistry; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D012623:Seawater; D013045:Species Specificity; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene; D019363:Cytochrome P-450 CYP1A1