EFFECTS OF 2,3,7,8-TCDD AND CONTAMINATED SEDIMENT ON THE CYTOCHROME P4501A ORTHOLOGUE IN RAINBOW-TROUT (ONCORHYNCHUS-MYKISS) AND CARP (CYPRINUS-CARPIO), USING CATALYTIC AND IMMUNOCHEMICAL TECHNIQUES

Polyclonal antibodies, anti-perch P4501A and anti-cod P4501A, both show cross-reactions with the P4501A orthologue in rainbow trout and carp. These fish were treated either with a single intraperitoneal dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), or exposed to Rotterdam harbour sediment, heavily contaminated with polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs) and polychlorobiphenyls (PCBs). In the fish exposed to a single TCDD dose the total P450 content was well correlated with both 7-ethoxyresorufin 0-deethylase (EROD) and P4501A protein content. For the sediment-exposed fish, the correlation between EROD and P4501A protein was lower. High correlations were found between EROD activity and the cytochrome P4501A content, as measured with enzyme-linked immunosorbent assay (ELISA) in both rainbow trout and carp. The higher correlations for the individual sampling periods, i.e. 3, 6 and 12 weeks, indicate a difference in time course between the EROD activity and P4501A protein content. Based on these results it is concluded that EROD, ELISA and, even a nonspecific parameter such as total P450 content, give supplemental information about the induction process.