Thermal and metabolic factors affecting bioaccumulation of triazine herbicides by rainbow trout (Oncorhynchus mykiss).
The bioaccumulation of the triazine herbicides terbutryn and terbuthylazine in rainbow trout was investigated at water temperatures of 4 degrees C, 10 degrees C, and 17 degrees C. The synergetic effect of water temperature and herbicide on fish liver detoxification metabolism was also studied by measuring liver ethoxyresorufin-O-deethylase (EROD) and UDP-glucuronosyltransferase (UDPGT) activities. The bioaccumulation of terbutryn increased significantly with increasing water temperature. However, temperature seemed to have no effect on the bioaccumulation of terbuthylazine. Both chemicals decreased the measured enzyme activities. Also, temperature effects were significant. In all tests the highest liver EROD activities were measured in fish exposed to a water temperature of 4 degrees C, and the activities decreased with increasing water temperature. The thermal effects on fish liver UDPGT activity differed between the herbicides. The highest activities at a water temperature of 4 degrees C were measured in fish exposed to terbutryn, whereas fish exposed to terbuthylazine had the highest liver UDPGT activities at 17 degrees C. Measuring liver detoxification metabolism together with bioaccumulation increases the understanding of bioaccumulation of chemicals in different environmental conditions.
Tarja
Nakari
N
Finnish Environment Institute, Hakuninmaantie 6, FIN-00430 Helsinki, Finland. tarja.nakari@ymparisto.fi
Kirsti
Erkomaa
E
Marja
Luotola
L
Kari
Ennola
E
D000818:Animals; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D006540:Herbicides / Q000493:pharmacokinetics*; D008658:Inactivation, Metabolic; D008099:Liver / Q000378:metabolism*; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D013696:Temperature; D014227:Triazines; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D006540:Herbicides; D014227:Triazines; D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1; D014453:Glucuronosyltransferase