CYP1A expression in liver and gills of rainbow trout (Oncorhynchus mykiss) after short-term exposure to dibenzothiophene (DBT).

ABSTRACT

Dibenzothiophene (DBT), a common component of crude oil, is a widespread environmental pollutant of known adverse effects to aquatic vertebrates. However, the molecular mechanism by which DBT exerts its effects still remains unknown. Our goal for this study was to examine DBT effects on CYP1A expression in liver and gills of rainbow trout after short-term exposure. Juvenile trout individuals were injected intraperitoneally with two doses of DBT (10 or 50mgkg(-1)) and were kept in tanks for 8 and 24h (T=14 degrees C), then their gene expression levels were evaluated by Real-Time qPCR and Western-blot analysis. Treatment with DBT at either dose decreased CYP1A mRNA levels through the exposure period, which resulted in the final decrease of CYP1A protein levels in liver and gills on the end of experiment (24h). Thus, our results showing significant depletion of CYP1A molecules in metabolic tissues upon DBT treatment correlate with those previous reports that indicate a role of DBT in reducing CYP1A activity in fish.