The mRNA levels of CYP1A, GST, and SOD1 were quantified by real-time RT PCR. CYP1A and antioxidant enzyme activities were dramatically higher at the Sarayköy station, where OCP pollution is higher than the other two stations. Mn-SOD is responsible for the increase in total SOD activity in the Sarayköy samples. However, gene expression levels of certain enzymes were heavily suppressed. Our findings show that the transcriptional and functional responses of CYP1A and antioxidant enzymes are inversely correlated.