Toxic Effect Of Organophosphorus And Organochlorine Pesticides On Zebrafish (Brachydanio Rerio)

The use of a large number of pesticides,most of which remain in the soil,the surface runoff into the water environment pollution caused by water,through the food chain into the human body,the impact on human health.The use of pesticides is very wide,agriculture,animal husbandry,fishery,the use of large,due to the use of a long time,to human health and water environment,a serious threat,causing widespread concern.In this paper,using zebrafish as experimental materials,the organic chlorine pesticide Cypermethrin,organophosphorus pesticide Phoxim and trichlorfon exposure to liquid,the semi static method,the research on zebrafish toxicity.The acute toxicity test of beta cypermethrin on zebrafish 96 h-LC₅₀(LC₅₀)value was 0.650 mg/L,highly toxic to aquatic organisms;Phoxim on zebrafish 96 h-LC₅₀ value was 6.482 mg/L,highly toxic to aquatic organisms;trichlorfon on zebrafish 96 h-LC₅₀ value was27.877 mg/L,toxic to aquatic organisms.Determination of Phoxim and trichlorfon combined toxicity to zebrafish,the results for the synergistic effect of combined use of greater toxicity to fish.The activity of Phoxim SOD,acetylcholinesterase?AChE?and peroxidase?POD?was determined by spectrophotometer:?1?Under the action of Phoxim,the protein concentration in the experimental group was higher than that in the control group,and the protease activity showed an upward trend.?2?In the experiment of 24 h,all exposure concentrations of SOD activity compared with the control group,increased significantly from low concentration group to group the change trend of high concentration firstly increased and then decreased,the concentrations are induced by different degrees,show that in zebrafish just contact phoxim,causing oxidative stress in zebrafish in vivo,by increasing the activity of SOD to resist external stimulation,reduce the effect of external stimulus of the body,in the 6 mg/L group effect on zebrafish head SOD activity reached maximum,the induction rate was 119%.With the extension of time,the activity of SOD in the head of zebrafish was decreased,and the activity of SOD was inhibited in the high concentration group.?3?Compared with the control group,the overall performance of zebrafish head acetylcholinesterase inhibition decreased,the control group of zebrafish head AChE activity remained unchanged,the experiment group and the activity of AChE were affected,AChE activity increased with the exposure concentration increased,compared with the control group showed a significant dose effect relationship.The longer the exposure time,the lower the activity of ACh E,which showed the time effect relationship.?4?The control group zebrafish head POD activity remained unchanged,the experimental group of phoxim stress POD activity showed first induced inhibition phenomenon;show that there is a significant time between POD activity and phoxim concentration effect relationship of brain tissue of zebrafish.In the low concentration group,zebrafish head POD activity was significantly higher than the control group,the activity of POD induced antioxidant capacity in zebrafish is activated in the high concentration group,the inhibition rate was significantly lower than the control group,with the increase of exposure concentrations,POD activity increased first and then decreased with the increased exposure time;growth and exposure concentration.A large number of free radicals induced by pollutants beyond the zebrafish resist ability,leading to cell damage,thus resulting in the decrease of POD activity.