The Effect Of Dual Blocking Ras System On Acute Kidney Injury Induced By Paraquat Poisoning In Rats

Objective : The effects of losartan and captopril on the inflammatory related factors and Ang II in the serum and renal tissues of rats with acute renal injury induced by paraquat poisoning were observed in order to explore the protective effect of double captopri on RAS system on acute renal injury in rats with paraquat poisoning.Methods:One hundred-twenty male Sprague-Dawley rats,weighting about200-250 g,were randomly divided into five groups(n=24 per group): the saline control group(group A),paraquat poisoning group(group B),losartan group(group C),captopril group(group D),combined with losartan and captopril group(group E).Four groups of B,C,D and E were given intragastric administration of paraquat once,and A group was given the same amount of normal saline for gavage.Group C,D,and E were administered to the stomach after paraquat,immediately given the C group of rats with losartan 60mg/kg,60mg/kg in group D,60mg/kg in group D,and E group with losartan 60mg/kg combined with captopril 60mg/kg,while group A and group B were replaced by equal amount of physiological saline,and repeated every 24 hours thereafter.The general condition of rats in each group was observed.After 1 days,3 days,7days,14 days later,6 rats were killed,and the specimens of abdominal aortic blood and kidney tissue were collected.The concentration of IL-6,IL-10 and Ang II was detected by ELISA.Hematoxylin eosin staining(HE)was used to observe histopathological changes in renal tissues.RT-PCR method was used to detect the relative expression of Ang II m RNA,NF-kappab m RNA and TNFalpha m RNA in rat kidney tissue.The expressions of NF-κB,TNF-α and IL-6proteins were detected by immunohistochemistry.Results:(1)The rats in the normal saline control group performed well,the intake of water was normal,the movement was smooth,the breathing was even,and the fur was clean and tidy.In the paraquat poisoning group,rats developed poisoning symptoms within 2 hours after exposure,manifesting as burnout,irritability,reduced intake of water in different degrees,bloody discharge from the nose and mouth,loose fluffy hair,slow movement,and easy capture.Oliguria or anuria.The above poisoning reactions were also observed in the losartan,captopril and combined losartan and captopril groups,but there was no significant difference.(2)HE staining showed that in the saline control group(group A),under light microscope,renal tubules and glomeruli were clear,and no interstitial congestion and inflammatory cell infiltration were found in renal interstitium and vessels.In paraquat poisoning group(group B),there were different degrees of congestion and edema of renal interstitium within hours after intoxication,accompanied by inflammatory cell infiltration and increased erythrocytes in glomeruli.With the increase of time,the damage is aggravated.There were no obvious morphological changes on the first day in the losartan group(group C)and captopril(group D),and pathological changes were compared with the paraquat poisoning group on the 3rd,7th,and 14 th days.Some relief.Compared with the paraquat poisoning group,the degree of pathological changes in the combined losartan and captopril groups(group E)was more pronounced.(3)ELISA showed that the concentration of Ang II,IL-6 and IL-10 in serum of B group increased with the prolongation of poisoning time.Compared with group B,the third days,seventh days and fourteenth days of group C,group D and group E showed a decreasing trend(P<0.05).There was no significant difference in the comparison between the first day of each group(P>0.05).(4)Immunohistochemical display:compared with the group A,the NF-κB,TNF-αand IL-6 in the group B were highly expressed,and increased rapidly on the first day,reached the highest to the third day,and decreased in seventh,fourteenth days(P<0.05).Compared with group B,there was a difference in the third,seventh,fourteenth day trend between group C,group D and group E,and was statistically significant(P<0.05).There was no significant difference in the expression time between group C and group D at different time points(P<0.05).Compared with group C and group D,the decrease of group E was more obvious(P<0.05).(5)PCR results showed that the expression levels of NF-κB and TNF-αm RNA in the remaining groups were significantly higher than those in A group at all time points.And the highest level of expression was on the third day,but over time,its expression level also gradually decreased,and the difference was statistically significant(P<0.05).The expression of Ang II m RNA in rats of group B,group C,group D and group E increased with time.The expression of group C,group D and group E on third days,seventh days and fourteenth days were significantly lower than those in group B,and the difference was statistically significant(P<0.05).There was no significant difference in the expression level between group C and group D at any time point(P > 0.05).The descending trend of group E was more obvious than that of group C and group D in third days,seventh days and fourteenth days,and was statistically significant(P < 0.05).Conclusions:(1)Paraquat poisoning rats kidney injury with the abnormal increase of Ang II,IL-6,IL-10,TNF-α and NF-κB.(2)Losartan and Captopril reduced the expression of IL-6,IL-10,TNF-α,NF-κB and Ang II in rat serum and kidney tissue,it reduced the degree of renal injury.(3)The drugs losartan and captopril may be the effective treatment for the prevention of renal damage caused by paraquat poisoning.