A species comparison of 17-α-ethynylestradiol uptake and tissue-specific distribution in six teleost fish.
Differences exist among fish species in their sensitivity to endocrine disruptors such as 17-α-ethynylestradiol (EE2). We examined whether there were corresponding differences in EE2 uptake rates and short-term internal distribution patterns. Six freshwater species: Japanese ricefish (medaka, Oryzias latipes), goldfish (Carassius auratus), zebrafish (Danio rerio), fathead minnow (Pimephales promelas), Atlantic killifish (Fundulus heteroclitus) and rainbow trout (Oncorhynchus mykiss) were exposed to waterborne radiolabelled EE2 (100ng/L) for 2-h measurements of uptake, tissue accumulation and oxygen consumption rates (MO2). EE2 uptake rate and MO2 were relatively consistent among species (2.5-3.0 fold variation), with the only significant differences being a lower EE2 uptake rate in medaka, and lower MO2 in medaka, goldfish, and zebrafish relative to the other species. EE2 accumulation, however, exhibited two distinct patterns, suggesting differences in metabolic processing. In killifish and medaka, the highest accumulation (~50%) occurred in the liver and gallbladder, whereas in minnow, goldfish, zebrafish and trout, >50% accumulated in the carcass. No significant sex differences were found in killifish or minnow, apart from lower gill tissue EE2 accumulation in minnow females. This study demonstrated that metabolic processing of EE2 may be species-specific and tissue specific EE2 distribution profiles vary. These could be indicative of differences in overall EE2 sensitivity among species.
Department of Biology, McMaster University, Hamilton, ON, Canada. Electronic address: blewetta@mcmaster.ca.
Tamzin A
TA
Blewett
Department of Biology, McMaster University, Hamilton, ON, Canada.
Tiffany L
TL
Chow
Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada.
Deborah L
DL
MacLatchy
Department of Biology, McMaster University, Hamilton, ON, Canada.
Chris M
CM
Wood
D000818:Animals; D052244:Endocrine Disruptors / Q000378:metabolism / Q000506:poisoning; D005260:Female; D005399:Fishes / Q000378:metabolism*; D005618:Fresh Water; D005704:Gallbladder / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000506:poisoning
D052244:Endocrine Disruptors; D014874:Water Pollutants, Chemical
17α-Ethynylestradiol (EE2); Fathead minnow; Goldfish; Japanese medaka; Killifish; Rainbow trout; Tissue distribution; Zebrafish