The Expressions Of Inflammatory Cytokines In The Renal Tissue Of Rats Induced By Paraquat And The Study On Effects Of Ulinastatin On Its

Objective:Trade name of paraquat is Gramoxone,chemical name of it1,1’-dimethyl-4,4’-dipyridylium.Because of its good effect on weeding and small pollution to the environment,it has quickly become a widely-used herbicide all over the world.With the wide application of PQ on agricultural production,the poisoning cases is gradually rising in China.PQ toxicity to humans and animals is very strong.Oral administration of PQ can cause severe organ function injury.PQ enters the body through skin contact,respiratory inhalation and gastrointestinal absorption.PQ is readily absorbed through skin,pneogaster or enteron.At present,the study of PQ poisoning has reached the molecular level,but its specific pathogenesis is still unclear.There is high mortality rate on account of lack of specific antidote heretofore.Therefore pathological mechanism of PQ poisoning is becoming a hotspot of current toxic therapeutics.After entering body and mainly aggregating in the lung,PQ cause lung injury.PQ is excreted as prototype from the kidney.So soundness of renal function is very important to remove absorbed PQ.Along with the research in recent years,PQ-induced pathophysiology may react with oxygen free radicals,oxidative stress,the release of inflammatory mediators,cell apoptosis and DNA damage and so on.Through the establishment of PQ-reduced rat models,the study observes the renal changes of pathophysiology,determinates the content of blood urea nitrogen（BUN）,creatinine（Cr）,malonyldialdehyde（MDA）and activity of superoxide dismutase（SOD）in plasma.Relying on the expressions of intercellular adhesion molecule-1（ICAM-1）,tumor necrosis factor alpha（TNF-alpha）,Interleukin-8（IL-8）in kidney tissue by immunohistochemistry,we have an attempt to explore physiopathologic mechanism and the remedial effect of Ulinastatin（UTI）on kidney damage induced by PQ.Methods:In the first place,PQ-reduced rat models are established.According to the digital meter method,one hundred and eight Sprague-Dawley rats（weighing:200-280g）are indiscriminately divided into 3 equal groups:group C（Control group,n=36）,group P（Poisoned group,n=36）,group P+U（UTI group,n=36）.PQ（25mg/kg）diluted with 0.9%NaCl is given intraperitoneally to group P and P+U,meanwhile Group C is disposed by the same way of 0.9%NaCl as group P and P+U.UTI（75mg/Kg）intraperitoneal injection is given to Group P+U once a day.After ether anaesthesia on 1^st,3^rd,7^th,14^th,21^st,28^th day,6 rats respectively from three groups were supinely in operation stage.The local skin of the abdomen was sterilized with iodine disinfectant after shaving.Abdominal aorta was expose The belly was cut so as to expose abdominal aorta.The blood was drawn and Bun,Cr,SOD activity,MDA concentration in blood were measured.The expression of ICAM-1、TNF-α、IL-8 in renal tissue was observed by the method of immunohistochemistry.Results:1.The general situation of rats after paraquat poisoning:the rats of group P and P+U took gradually on different clinical appearance in half an hour to two hours,revealing anorexia water,listlessness,apathy,irritability,a lot of secretions around mouth,nose and eyes,cyanosis of the extremities,and so on.Nevertheless,all the rats of group P+U revealed milder poisoning expressions than those in group P.2.Blood plasma measurement1)The serum levels of BUN in group P ascended more notably than those of group C on the 1^stt to 14^th day（P<0.01）,on the 21^st,28^thh day（P<0.05）;While the ascents of BUN in group P+U were observably restrained,in which,the contents of BUN on the 1^st to 21^stt day declined more conspicuously than group P（P<0.05）.Compared with those in group C,the levels of BUN in group P+U kept highly on the 1^stto 21^st day（P<0.05）.2)Compared with group C,The levels of serum Cr in group P rose remarkably at all time points（P<0.01）;After UTI treatment,the ascents of Cr in group P+U were significantly intibited.The contents of serum Cr at all time descended more significantly than those in group P（P<0.05）.The levels of Cr in group P+U remained statistically significantly higher than group C at all time（P<0.05）.3)In comparison with group C,the contents of MDA in group P rose markedly on the 1^st,3^rd,7^th day（P<0.01）,on the 14^th,21^stt day（P<0.05）;While the rises of serum MDA were significantly restrained in group P+U,in which,the contents of MDA on the 1^stt to 14^th day were obviously lower than those of the group P（P<0.05）.Compared with group C,there are statistically significant on the 1^st to 7^th day（P<0.05）.4)In comparison with those of group C,The descent of serum SOD activity in group P was statistical significant on the 1^st to 14 ^th day（P<0.05）.After UTI treatment,the activity of SOD in group P+U was higher than that of group P on the 1^st to 14 ^th day（P<0.05）,but was lower than group C on the1^st,3^rd day（P<0.05）.There were not statistical significant at other time points（P>0.05）.3.Hematoxylin-eosin staining observation:Group P:The volume of rat kidney guadually increased.It became dark red and there were the scattered blood stasis.Observation under high-power microscope:a small amount of red blood cells gathered around renal glomerulus.There is hyperemia along with inflammatory cells infiltration in renal interstitial.After PQ poisoning,the epithilial cell of renal tubular became swelling,vacuolar degeneration and necrosis.The above changes in renal tubule gradually lessened on 21^st day.UTI treatment relieved the pathological changes in rats kidney.4.Performance of IH staining before and after treatment:1)In the renal tissue of group C,there lay very infirm expressions of ICAM-1、TNF-α、IL-8.2)After PQ poisoning,the expressions of ICAM-1、TNF-α、IL-8 in group P were significantly stronger than those of control group on the 1^stt day which were chiefly viewed in the nucleus and cytoplasm of renal tubule epithelial cells.There lay statistical significant between group C and P at all time points（P<0.05 or 0.01）.By means of UTI treatment,the expressions of ICAM-1、TNF-α、IL-8 in group P+U became weakened.In comparison with group P,the expressions of ICAM-1、TNF-α、IL-8 in group P+U were obviously lower at all time（P<0.05 or 0.01）.Conclusions:1.The strong expression of ICAM-1、TNF-α、IL-8 in rat kidney after PQ poisoning indicated that the models of renal injury induced by PQ were successfully established in study.2.After PQ intraperitoneally poisoning,the treatment of UTI could significantly inhibit the expression of inflammatory factors ICAM-1,TNF-,IL-8,and improve the renal function of rats.The mechanism of UTI relieving renal injury induced by PQ is to down the expression of ICAM-1,TNF-,IL-8,to eliminate oxygen free radicals and inhibit oxidative stress.The results provide a theoretical basis for the clinical application of UTI and the PQ treatment.