Glutathione S-transferase cytosolic isoforms as biomarkers of polychlorinated biphenyl (Arochlor-1254) experimental contamination in rainbow trout.

At the present work, different groups of rainbow trouts have been intraperitoneally treated with a polychlorinated biphenyls commercial mixture (Arochlor-1254) at three doses (5, 20 and 70 mg PCBs/ kg body weight) and they have been sampled at 0 (injection moment), 3, 6 and 9 weeks after xenobiotic exposure. Purification and characterization of the cytosolic isoforms of glutathione S-transferases from three different rainbow trout organs (liver, kidney and gills) have been developed in order to establish the existence of some enzymatic induction process. According to the enzymatic activity levels and protein content, liver samples showed the highest glutathione S-transferases induction process, and resulting dose and time dependent. Directly related, HPLC results from liver retained-affinity purified samples determined that this process was mainly associated to a pi-class related isoenzyme. Only some of the different GST isoenzymes from rainbow trout liver cytosol showed to be specifically induced by the polychlorinated biphenyls treatment, rendering these isoenzymes as valuable biomarkers for exposure to these environmental pollutants.