PARENT SESSION
PM14 - Role of Biomarkers/Bioindicators in Ecological Risk Assessment
Monday, 18 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P338) CYP1A expression in longear sunfish as a biomarker of PCB exposure.
Brammell, Ben*,1, Price, David1, Arzuaga, Xabier1, Birge, Wes1, Elskus, Adria1, 1 University of Kentucky, Lexington, Kentucky, United States
ABSTRACT- Induction of cytochrome P-450 1A occurs in response to exposure to environmental pollutants such as polyhalogenated aromatic hydrocarbons and polycyclic aromatic hydrocarbons and is a widely used biomarker of exposure to these compounds. Studies with a number of species have demonstrated levels of CYP1A protein expression and activity that are higher in fish at polluted sites relative to fish captured from clean sites. Longear sunfish (Lepomis megalotis) are found in a variety of freshwater ecosystems. The widespread distribution of this species and the fact that they spend their entire life within a small area make them good habitat sentinels and thus good candidates for biomonitoring. Recent studies in our laboratory indicate longear sunfish demonstrate relatively low sensitivity to induction of CYP1A following exposure to polychlorinated biphenyls (PCBs). Longear sunfish collected from a PCB contaminated site had relatively low levels of CYP1A activity (measured as hepatic microsomal ethoxyresorufin-o-deethylase, EROD) similar to EROD activities obtained in fish collected from a clean site. Longear from the contaminated site had muscle tissue PCB concentrations associated with CYP1A induction in other species. Results from laboratory studies indicate that CYP1A protein levels in fish injected with varying concentrations of PCB 77 were similar to controls. We propose that CYP1A activity may be an inadequate biomarker of PCB exposure in longear sunfish and possibly other members of the Lepomis genus.
Key words: CYP1A, longear sunfish, biomonitor, polychlorinated biphenyl