Gill filament-based EROD assay for monitoring waterborne dioxin-like pollutants in fish.
A sensitive, accurate, and straightforward way to determine basal and induced ethoxyresorufin O-deethylase (EROD) activities in gill filaments, using rainbow trout as model species, is described. Tip pieces of primary gill filaments were incubated in tissue culture plate wells containing HEPES-Cortland buffer supplemented with 7-ethoxyresorufin. Each well was sampled on two occasions, and resorufin concentrations were determined by measuring the fluorescence with a plate reader. EROD activity was calculated from the difference in resorufin concentration and the interval between the two samplings. EROD activity was found to be significantly induced by 6 h of exposure to waterborne beta-naphthoflavone (1 microM). EROD in gills was also induced by caging rainbow trout in a polluted river or by laboratory exposure of fish to water extracted from that river. There was no loss of EROD activity when gill tissue was kept in ice-cold buffer for up to 1 d, which promotes the use of the method for studying fish exposed in the wild. We propose this novel method as a way to monitor dioxin-like compounds in aquatic environments.
Department of Environmental Toxicology, Evolutionary Biology Centre, Uppsala University, Sweden.
E Maria
EM
Jönsson
Ingvar
I
Brandt
Björn
B
Brunström
D000818:Animals; D001681:Biological Assay; D019363:Cytochrome P-450 CYP1A1 / Q000032:analysis / Q000494:pharmacology*; D004147:Dioxins / Q000009:adverse effects*; D004784:Environmental Monitoring / Q000379:methods; D005880:Gills / Q000502:physiology*; D017686:Oncorhynchus mykiss / Q000502:physiology*; D012680:Sensitivity and Specificity; D014873:Water Pollutants / Q000009:adverse effects*
D004147:Dioxins; D014873:Water Pollutants; D019363:Cytochrome P-450 CYP1A1