EFFECTS OF CHLORPYRIFOS INSECTICIDE ON CYP1 FAMILY GENES EXPRESSION AND ACETYLCHOLINESTERASE ENZYME ACTIVITY IN ORYZIAS JAVANICUS

摘要

dEffects of chlorpyrifos (0.01-0.5 mg/L) on differential expression of CYP1 genes in exposed-fish tissues for 5 days and characteristics of the intrinsic variations of acetylcholinesterase (AChE) activity and recovery in medaka fish tissues were evaluated for 20 days. Javanese medaka CYP1 genes transcript expression was detected in all tissues, including the liver, gill and intestine of the fish exposed to different concentrations of the insecticide for 5 days. The CYP1A gene induction level in each tissue increased with higher concentrations of chlorpyrifos. CYP1B1 transcription was detected in all of observed tissues. The CYP1C1 transcription in all evaluated tissues increased 2- to 5-fold at all chlorpyrifos levels after 1 day of exposure. Significant effects and interactions of the insecticide concentrations and exposure time were found in fish tissues AChE activity. A trend occurred in which AChE inhibition increased with higher insecticide concentrations and exposure duration. Tissue AChE activity was significantly inhibited after 1 day of exposure to the chemical, but liver AChE activity showed the lowest concentration. Recovery was occurred after holding the fish in clean water for 5 days, but the activity in all exposure groups was still significantly lower than that in the control group. Full recovery was only found in liver AChE activity after keeping the fish in clean water for 15 days at the lowest concentration. The findings of the study can serve as sensitive multi-biomarkers to characterize toxicological impacts and monitor aquatic environments.