Study On The Effect Of Taurine On The Antioxidative Effect Of Broiler Myocardium Under Low Temperature

Ascites syndrome(AS)is a metabolic disease characterized by peritoneal effusion and heart failure in sick chickens.The typical feature of this disease is right heart hypertrophy in chickens.It is a major cause of death in broiler chickens.There is a close relationship between occurrence and low temperature environment.Long-term low temperature will cause the occurrence of oxidative stress in broiler chickens,increase the content of active oxygen in the broiler's myocardium,the dynamic imbalance between oxidation and antioxidant systems,and ultimately damage the myocardium.Keap1/Nrf2 signaling pathway plays a very important role in myocardial anti-oxidative damage.Taurine is the most abundant free amino acid in cardiomyocytes,which can improve the antioxidant capacity of cells and regulate the Keap1/Nrf2 signaling pathway.At present,there is no research report on whether Keap1/Nrf2 signaling pathway is involved in myocardial hypertrophy injury in broilers.Therefore,in this experiment,the right ventricular hypertrophy of broiler chickens was induced by low temperature,taurine was added to drinking water,and H9c2 cell hypertrophy was induced by isoproterenol(ISO)in vitro to explore the Keap1/Nrf2 signaling pathway in the process of broiler cardiac hypertrophy The impact of the treatment provides a theoretical basis for the application of taurine in the prevention and treatment of ascites syndrome.In the broiler feeding experiment,240 14-day-old broilers were randomly divided into three groups,the control(C)group,the low temperature(M)group,and the taurine low temperature(T)group.The right ventricular muscle tissue was collected at the age of 35 days.TBA method was used to detect MDA content,colorimetric method to detect GSH-Px activity,LDH activity,microplate method to detect SOD activity,visible light method to detect CAT activity;fluorescence quantitative PCR method to detect myocardial antioxidant genes(PI3K,AKT,Hsp70,Keap1,Nrf2,HO-1,NQO1,?-gcs,GCLC,GSH-Px)m RNA expression levels.(1)Antioxidant enzyme determination results: Compared with group M,the activities of SOD,CAT,and GSH-Px in group M were significantly decreased(P<0.01).Group T was compared with group M.In group T,SOD,The activities of CAT and GSH-Px increased significantly(P<0.01);compared with group C,the contents of MDA and LDH in group M increased significantly(P<0.01),group T compared with group M,T The content of MDA and LDH in the group decreased significantly(P<0.01).(2)Taurine on the expression of Keap1/Nrf2 signaling pathway factor m RNA in broiler myocardium: Compared with group C,Hsp70,PI3 K and AKT m RNA in group M were significantly increased(P<0.01),group T and group M Compared with group T,Hsp70,PI3 K and AKT m RNA decreased significantly(P<0.05);group M compared with group C,the levels of Keap1,Nrf2,HO-1,NQO1,?-gcs,GCLC,and GSH-Px m RNA in group M The expression level decreased(P<0.05).Compared with the M group,the T group Keap1,Nrf2,HO-1,NQO1,?-gcs,GCLC,and GSH-Px m RNA expression levels were significantly up-regulated in the T group(P<0.05).In the cell test,H9c2 cells were randomly divided into: control group(C group),control taurine group(CT group),ISO group(M group),ISO group+taurine(MT group).The determination method and index are the same as above.The results of the determination showed that:(1)Antioxidant enzyme determination: Compared with group C,the activities of SOD,CAT and GSH-Px in group M decreased significantly(P<0.01),group T was compared with group M,group T The activities of SOD,CAT,and GSH-Px increased significantly(P<0.01);compared with group C,the contents of MDA and LDH in group M increased significantly(P<0.01),group T and group M Compared with,the content of MDA and LDH in the T group was extremely significantly decreased(P<0.01).(2)Taurine results in the expression of Keap1/Nrf2 signaling pathway factor m RNA in H9c2 cells: Compared with group C,the expression of Hsp70,PI3 K,AKT,HO-1,and ?-gcs m RNA in group M increased significantly(P<0.01).Compared with group M,the expression of Hsp70,PI3 K,and AKT m RNA in CT group decreased significantly(P<0.05);compared with group C,group M had Keap1,Nrf2,NQO1,GCLC,GSH-Px m RNA expression level decreased(P<0.05).Compared with M group,CT group Keap1,Nrf2,HO-1,NQO1,?-gcs,GCLC,GSH-Px m RNA expression levels were significantly up-regulated(P< 0.05).1.After taurine treatment,the activity of antioxidant enzymes SOD,GSH-Px and CAT in myocardium and H9c2 cells increased,and the content of LDH and MDA decreased.It is speculated that taurine can increase the antioxidant capacity of myocardium and H9c2 cells and maintain myocardium and H9c2 Cell function.2.After taurine treatment,the negative regulatory factors Hsp70,PI3 K,and AKT m RNA were down-regulated,and Keap1,Nrf2,HO-1,NQO1,?-gcs,GCLC and GSH-Px m RNA were up-regulated.It can be inferred that taurine participates in the regulation of Keap1/Nrf2 pathway and plays an antioxidant role in protecting myocardium.In summary,taurine may enhance myocardial antioxidant capacity by up-regulating the Nrf2 signaling pathway,thereby protecting broiler myocardium under low temperature conditions.