Effects Of Single And Combined Exposure Of Atrazine And Chlorpyrifos On Gonad,Serum And Related Indicators Of Common Carp

Atrazine is a herbicide which is a nitrogen-containing triazine compound and chlorpyrifos is a kind of organophosphorus insecticides.These are two commonly used pesticides in modern agricultural production,which could penetrate into aquatic system and affect aquatic organism,especially fish,through leaching,runoff and other methods.Aquatic environmental toxicology has been a burgeoning research focus,which refers to biology,phytology,microbiology,medicine and other fields.In this experiment,by using carp as model animals and first applying gene cloning technique to clone ER-a 和 VTG-Ⅱ gene,we studied the effects of single atrazine(0.428 and 0.428μg/L)and chlorpyrifos(0.116 and 0.116 μg/L)and combined treatment of atrazine and chlorpyrifos(0.113 and 0.113 μ/L)subchronic exposure on carp’s antioxidant capacity,residue in carp;s liver tissue and related genes amplification(ER-a and VTG-II).Our purpose is to enrich the toxicology theory of fish and provide the basis of the healthy breeding of fish.The results prove that:1.Through the observation of pathological section,results show that,compared with control group,the development rate of females carps’gonad in each treatment group is accelerating,while which of males carps slows down,which accounts for that atrazine(A)and chlorpyrifos(D)has auxo-action to the development of ovary but inhibiting effect to testes.From high to slow the sequence of the development rate of female fish gonad in each treatment group is the mixture of atrazine and chlorpyrifos at high concentration group(HG),atrazine at high concentration group(AG),chlorpyrifos at high concentration group(DG),the mixture of atrazine and chlorpyrifos at low concentration group(HD),atrazine at low concentration group(AD),chlorpyrifos at low concentration group(DD),solvent control group(BT)and blank group(KB).From high to slow the sequence of the development rate of male fish testes in each treatment group is KB、BT、DD、AD、HD、DG、AG、HG.2.The results of gas chromatographic showed that,under the exposure of single atrazine or the mixture with chlorpyrifos(H),the residual quantity of atrazine in carps’ liver tends to degression.With AD,AG,HD,HG for 525d the results are respectively 2.2111、2.7364、1.4025、1.6924μg/kg.The differences between each group is obvious(P<0.01),the residual quantity of atrazine in high concentration groups is higher than low concentration groups(P<0.05),which of the mixture treatment group is obviously lower than single atrazine treatment group(P<0.05).Under the exposure of single chlorpyrifos or the mixture with atrazine,the residual quantity of chlorpyrifos in carps’ liver tends to degression.With AD,AG,HD,HG for 525d the results are respectively 1.5374、2.0106、0.7682、1.2103μg/kg.The differences between each group is obvious(P<0.01),the residual quantity of chlorpyrifos in high concentration groups is higher than low concentration groups(P<0.05),which of the mixture treatment group is obviously lower than single chlorpyrifos treatment group(P<0.05).3.Through the detection of the effect to alkaline phosphatase,glutamic-pyruvic transaminase,total protein,albumin,blood glucose,hysozyme,glutathlone reductase and oxidation resistance of carps’ serum under the expose of singe atrazine or chlorpyrifos and their mixture,the results show that,compared with the control group,except BT group,the concentrations of alkaline phosphatase,glutamic-pyruvic and blood gulcose other treatment groups are all obviously increaasing(P<0.01 or P<0.05).Compared with control group,except BT group;the contents of total protein,albumin,lysozyme and glutamic-pyruvic are all obviously decreasing(P<0.05 or P<0.01).Compared with KB group,except BT group,the oxidation resistance of other groups are all in decline(P<0.05 or P<0.01).4.ER-a and VTG-Ⅱ gene are respectively 3439bp and 5003bp,whose homology with zebra fish are respectively 98%and 95%.The RT-PCR examination shows that ER-a mRNA and VTG-Ⅱ in carps liver are expressed in a high percentage under the expose of singe atrazine or chlorpyrifos and their mixture.The mean level of expression of ER-a mRNA in carps liver tissue is atrazine group,A-C group and chlorpyrifos group from,which is descending and all higher than blank control group,obviously different(P<0.05).The mean level of expression of VTG-ⅡmRNA in carps liver tissue is atrazine group,A-C group and chlorpyrifos group from,which is descending and all higher than blank control group,obviously different(P<0.05).So both the two have environmental estrogen effects.To sum up,after the subchronic expose of singe atrazine or chlorpyrifos and their mixture,the content and the expression of ER-a and VTG-Ⅱ mRNA are increasing,which promoted the development of female fish gonad but inhibit male testes’ development.It could bring about serum changes and also influence on liver tissue,so that the function of liver and the antioxidant system in the body are abnormal.The situation of toxic residue is,atrazine is higher than the mixture and the mixture is higher than chlorpyrifos,decreasing with time more rapidly.The results show that carps liver have strong ability of degradation to atrazine and chlorpyrifos,which have no gathering in liver.