The Research Of The Toxic Mechanism Of Dimethyl Phthalate To Danio Rerio

Phthalate(PAEs)is a chemical additive that is commonly used in plastic products to make plastics soft and elastic.Due to the widespread use of plastic products and personal care products,it is introduced into organisms and the environment.In recent years,it can cause a series of endocrine disrupting effects of internal reaction at low concentration,so it has been paid more and more attention by domestic and foreign schola rs.Dimethyl phthalate(DMP)is one of the most common types of PAEs,and it is also the simplest one with the smallest molecular weight.It is generally believed that the toxicity of PAEs is positively related to the size of side chain groups.Therefore,the study of toxicity to DMP is relatively less than the other common PAEs.However,DMP has been listed as one of the most priority pollutants to be controlled,and monoester phthalate(MMP),the first metabolite of DMP after entering the organism,has higher toxicity,so it should be paid more attention.Zebrafish,as a model organism,has become an excellent biological model for studying toxicity mechanism due to its various advantages.In order to further explore the toxicities mechanism of DM P,zebrafish was selected as a biological model to study the toxicity of DMP to zebrafish under short-term acute exposure and long-term chronic exposure.The half lethal concentration(LC50,)of DMP was measured during short-term acute exposure,and the changes of biomarkers in oxidative stress,energy metabolism and immunity of zebrafish were measured at protein and molecular levels respectively.The activities of superoxide dismutase(SOD),catalase(catalase)and glutathione(GSH)and malondialdehyde(MDA)were measured at different concentrations of DMP.It was found that with the increase of DMP concentration,SOD,CAT,GSH increased at first,and then decreased.The content of MDA remained unchanged at first,and then increased.At the molecular level,the changes of oxidative stress,energy metabolism and the expression of immune-related genes were measured by real-time fluorescence quantitative PCR.The results showed that DMP could affect the expression of genes related to oxidative stress and caused oxidative damage and the transformation from aerobic glycolysis pathway to anaerobic glycolysis pathway and the decrease of non-specific immune function at the same time.The body weight of zebrafish was measured at 30d,60d and 90d during long-term toxic exposure.The expression of hypothalamic-pituitary-thyroid(HPT)axis genes related to the regulation of thyroid hormone secretion by zebrafish was examined at molecular level.It was found that long-term exposure to DMP at environmental concentrations would cause the disorder of thyroid function in zebrafish.