CYP1A expression in the hepatopancreas of Mullus barbatus, Merluccius merluccius and Trigla lucerna at the mouth of the river Bojana

CYP1A is one of the most sensitive biomarkers in fish of exposure to polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). These compounds induce a dose-dependent transcriptional induction of the CYP1A gene that results in increased protein concentrations. The aim of this study was the detection of changes in CYP1A protein levels as a result of the exposure of fish to PAHs and PCBs at the mouth of the river Bojana in the spring. The PAH and PCB contents in seawater and sediment were determined by gas chromatography. CYP1A induction was examined in the hepatopancreas of Red mullet (Mullus barbatus), European hake (Merluccius merluccius) and Tub gurnard (Trigla lucerna) by immunoblot analysis. Chemical analyses of seawater and sediment revealed the presence of several PAHs and PCBs. CYP1A was detected in the hepatic microsomal fraction in all examined fish species as an adaptive response to the presence of pollutants. The reported changes at the molecular level represent an early-warning signal that reflected the biological response of fish to elevated toxin concentrations in the environment.