| Excessive absorption of salt is more important to cause ascites problems（ascites syndrome,AS）and destruction in broilers.Compared with the salt in the diet,broilers are more sensitive to salt in the drinking water.80 1-day-old AA broilers were randomly divided into 4 groups after 7 days of normal development,and fed with different concentrations:scenario（Control,C;0%Na Cl）;low-salt group（Freshwater,L-SW;0.1%Na Cl）;medium Salt group（low saline,M-SW;0.25%Na Cl）;high salt group（high saline,H-SW;0.5%Na Cl）,performed on 35 days;using chicken embryo kidney cells（CEK cells）as the test object,using external Source Ang Ⅱ to treat cells.In this experiment,80 1-day-old AA broilers were fed normally for 7 days and then randomly divided into 4 groups,fed with different concentrations of salt water:control group（Control,C;0%Na Cl）;fresh water group（Freshwater,L-SW;0.1%Na Cl）;Low-salt water（M-SW;0.25%Na Cl）;high-salt water（H-SW;0.5%Na Cl）.Using chicken embryo kidney cells（CEK cells）as the test object,the cells are treated with exogenous Ang Ⅱ.The results of blood biochemical tests,ELISA tests,kidney tissue sections and TUNEL tests,fluorescent real-time quantitative PCR and western blotting show that:（1）Broilers HCT>0.36 accounted for 30%in M-SW group,and AHI>0.28 accounted for5%;broilers H-SW group HCT>0.36 accounted for 65%;AHI>0.28 accounted for 30%;meanwhile,broiler chickens in H-SW group developed ascites symptoms.The kidney index（kidney weight/body weight）of broilers in the M-SW group and H-SW group was significantly higher than that in the C group（P<0.01）,and there was no significant difference in the kidney index of the broiler chickens in the M-SW group and the H-SW group（P>0.05）.Serum biochemical results showed that the CRE and BUN of broilers in the M-SW group and H-SW group gradually increased with the increase of the time of using saline（P<0.01）.HE staining of kidney tissue showed that the kidneys of broiler chickens in the M-SW group and H-SW group had different degrees of vacuolar degeneration and fibrosis,accompanied by lymphocyte infiltration and nuclear pyknosis.And TUNEL test showed that the kidneys of broiler chickens in the M-SW group and H-SW group had apoptosis.Western blotting test showed that the phosphorylation of JAK2 and STAT3 in the kidneys of broilers in the M-SW group and H-SW group was significantly increased（P<0.01）,and renal aquaporin（AQP2）and renal type 3 sodium hydrogen exchanger（NHE3）were expressed Significantly increased（P<0.01）.The ELISA test results showed that the serum angiotensin Ⅱ（Ang Ⅱ）of the L-SW group increased significantly（P<0.05）,and the serum Ang Ⅱ of the M-SW group and the H-SW group increased significantly（P<0.01）.The serum Ang Ⅱ level of broilers in the H-SW group reached the highest peak on the 28th day.The Ang Ⅱ level of the broilers in the M-SW group increased with the increase of the salt water use.At 35 days,the serum Ang Ⅱ concentration of the broilers in the M-SW group was higher than that in the H-SW group（P<0.01）.The results of q RT-PCR showed that the expression of REN and ACE in broilers in each group increased significantly（P<0.01）,and the expression of AGT in broiler chickens in the M-SW group and H-SW group increased significantly（P<0.01）.The expression of the three genes in the M-SW group was significantly higher than that of the other groups（P<0.01）.Correspondingly,the Western blot results showed that the expression of angiotensin Ⅱ type 1 receptor（AGTR1）protein in the kidneys of the M-SW group and H-SW group was significantly increased（P<0.01）,and the expression of AGTR1 in the kidney of broilers in the M-SW group was the highest.（2）After treating the cells with 10-7M,10-6M,10-5M exogenous Ang Ⅱ for 24 h,CCK-8 results show that CEK cell activity decrease with the increase of exogenous Ang Ⅱ concentration,and it is significantly different from the control group（P<0.01）.Cells are treated with 10-5M exogenous Ang Ⅱ for 12h,24h,and 48h after flow cytometry.With the increase of exogenous Ang Ⅱ treatment time,cell apoptosis increase,and there is a significant difference compared with the control group（P<0.01）.Western blot results showed that10-6M Ang Ⅱ（P<0.05）and 10-5M Ang Ⅱ（P<0.01）can significantly increase the expression of AGTR1 in CEK cells.10-6M Ang Ⅱ（P<0.05）and 10-5M Ang Ⅱ（P<0.01）can significantly increase JAK2/STAT3 phosphorylation in CEK cells.10-6M Ang Ⅱ（P<0.05）and 10-5M Ang Ⅱ（P<0.01）can significantly increase the expression of AQP2 in CEK cells;10-5M Ang Ⅱ can significantly increase the expression of NHE3 in CEK cells（P<0.01）.In summary,high-salt drinking water can induce AS in broilers;by promoting the increase of Ang Ⅱ in broilers,inducing the increases of AGTR1;inducing abnormal increases AQP2 and NHE3 in kidney to affect water and salt metabolism;activating the JAK2/STAT3 pathway to induce kidney damage. |
