%0 Journal Article
%T Effects of redox cycling compounds on DT diaphorase activity in the liver of rainbow trout (Oncorhynchus mykiss)
%A Joachim Sturve
%A Eir¨ªkur Stephensen
%A Lars F£¿rlin
%J Comparative Hepatology
%D 2005
%I BioMed Central
%R 10.1186/1476-5926-4-4
%X In rainbow trout, hepatic DTD activity is induced by the bifunctional AHR agonists ¦Â-NF and B(a)P and the monofunctional inducers naphthazarin, menadione and paraquat. Although exposure to both B(a)P and ¦Â-NF led to a strong 7-ethoxyresorufin-O-deethylase (EROD) induction, none of the monofunctional compounds affected the rainbow trout EROD activity. DTD was not induced by ¦Â-NF in any of the other fish species. Much higher DTD activities were observed in rainbow trout compared to the other fish species. Catalase activity was less responsive to short term exposure to prooxidants compared to DTD.Since rainbow trout hepatic DTD activity is inducible by both monofunctional and bifunctional inducers, it is suggested that rainbow trout DTD may be regulated by the same mechanisms, as in mammals. The fact that DTD is inducible in rainbow trout suggests that the enzyme may be suitable as a part of a biomarker battery when rainbow trout is used in environmental studies. It appears as if DTD activity in rainbow trout is higher and inducible compared to the other fish species studied.The aquatic environment is exposed to a great number of pollutants. Effluents from industries and sewage treatment plants as well as drainage from urban and agricultural areas contain pollutants that may damage aquatic life. A large part of these compounds exert their toxic effect by generating reactive oxygen species (ROS), causing oxidative stress [1]. Compounds such as quinones, certain polycyclic aromatic hydrocarbons (PAH) metabolites and bipyridils generate ROS through their ability to redox cycle, a process where an enzymatic one electron reduction of the parent compound is followed by an autooxidation in the presence of molecular oxygen [2]. In this reaction, the oxygen will be reduced to a superoxide ion that can lead to the formation of other ROS such as hydrogen peroxide (H2O2) and hydroxyl radicals [3]. ROS causes cell injury by oxidizing lipids, proteins and DNA leading to membrane dam
%U http://www.comparative-hepatology.com/content/4/1/4