Effects of di-n-butyl phthalate on gills- and liver-specific EROD activities and CYP1A levels in juvenile red snapper (Lutjanus argentimaculatus)

Di-n-butyl phthalate, one of the most easily detected pollutants of phthalate esters in the environment, has been added to the priority list of hazardous substances by many countries. As one of low molecular weight phthalates, Di-n-butyl phthalate may have a great adverse potency on various aquatic organisms. In this study, the juvenile red snapper, Lutjanus argentimaculatus, was exposed to the concentrations of Di-n-butyl phthalate (20 mu g L-1, 100 mu g L-1 and 500 mu g L-1) for 15 days. EROD activities and CYP1A levels were measured in liver and gill tissues. In gills, the similar effect has been found to inhibit or induce EROD activities and CYP1A levels, and there existed a good correlation between them. Whereas in the case of the liver, a moderate correlation was observed between EROD activities and CYP1A levels, which was mainly due to the inhibited EROD activities and the CYP1A levels with no significant difference by day 15. In conclusion, this study revealed the similar and different effects of cytochrome P450 enzymes on fish in the time-, concentration-, and tissue-dependent Di-nbutyl phthalate exposure. Furthermore, as the adverse effects indicated between CYP1A levels and EROD activities, metabolic mechanisms of phthalates in different tissues should be highly emphasized in future studies.