Study On EHDPHP-Induced Oxidative Stress And Cell Apoptosis In Chicken Kidneys

Organic phosphorus flame retardants(OPFRs)are widely used in many industries due to their excellent performance.However,the widespread application of OPFRs is often accompanied by increasingly serious environmental pollution and biosafety hazards.2-ethylhexyl diphenyl phosphate(EHDPHP)is a widely used organophosphorus flame retardant.Studies have shown that EHDPHP intake can cause abnormal development in mice,but its specific mechanism is not fully understood.The research on the biological toxicity of EHDPHP on poultry is almost blank.Therefore,in order to detect the toxic effects and mechanisms of EHDPHP on chickens,this experiment selected the EHDPHP metabolic organ kidney as the target organ to study the oxidative stress and cell apoptosis in EHDPHP poisoned chicken kidneys.In this experiment,90 pre-fed 7-day-old Hyland white feather laying hens were selected and treated with different concentrations of EHDPHP by gavage.Kidney samples were taken for detection and analysis on the 14 th,28th,and 42 nd days after gavage.This experiment examined the impact of EHDPHP on the growth and development of chickens by examining their clinical symptoms and changes of weight,examined the damage caused by EHDPHP to the renal morphology and structure through changes in chicken kidney dissection and histopathological changes,analyzed the effect of EHDPHP on renal function through changes in urea nitrogen(BUN)and creatinine(Cr)in chicken serum,analyzed the effect of EHDPHP on the level of oxidative stress in the kidney and mitochondria through the changes of reactive oxygen species(ROS)and malonaldehydic acid(MDA)content,superoxide dismutase(SOD)activity and mitochondrial membrane potential in chicken kidney,and detected the expression changes of apoptosis related factors(pro-apoptotic factors Caspase-3,Caspase-8,Caspse-9,BAX,and anti-apoptotic factor Bcl-2)in chicken kidneys using real-time fluorescence quantitative PCR and Western Blot methods.The results showed that under EHDPHP exposure chickens grew slowly,the kidneys were swelled,the color became darker,the texture was brittle,and the organ index was significantly increased.Under the microscope,different degrees of apoptosis can be seen in the renal tubular epithelial cells,mainly manifested as deep cytoplasm staining,nuclear chromatin condensation,cell shrinkage and rounding,and the basement membrane was not closely linked.At the same time,cell necrosis and dissolution and increased number of erythrocyte in the stroma were observed.The results of serological examination showed that the contents of BUN and Cr in serum of EHDPHP exposure group were increased(P<0.05).The results of oxidative stress kit showed that the level of oxidative stress in the kidney of chickens increased significantly under EHDPHP exposure,mainly manifested by the increase of reactive oxygen species and peroxide product MDA content(P<0.05),and the activity of antioxidant enzyme SOD decreased significantly(P<0.05).Meanwhile,exposed to EHDPHP also significantly decreased in renal mitochondrial membrane potential(P<0.05)and changed apoptotic factors.The m RNA and protein expression levels of pro-apoptotic factors(Caspase-3,Caspase-8,Caspse-9,BAX)in the kidney were significantly increased(P<0.05),and the m RNA and protein expression levels of anti-apoptotic factors(Bcl-2)were significantly decreased(P<0.05).The above changes were aggravated with the increase of EHDPHP concentration.The results showed that EHDPHP can cause chicken kidney damage through oxidative stress and apoptosis,and inhibit the growth and development of chickens.This study provides a scientific basis for further exploring the toxic damage mechanism of EHDPHP and the safe use and pollution control of EHDPHP.