The Protective Effect Of Dexmedetomidine On SAKI In Rats By Regulating The NF-?B/AP-1-iNOS/NO Pathway

Septic acute kidney injury?SAKI?is a systemic complication of high clinical morbidity and mortality in veterinary medicine.The search for effective drugs and the elucidation of key pharmacodynamic mechanisms are the focus of research in this area.Previous studies on the pathophysiology of SAKI have focused on inflammatory response.In recent years,the focus of research has shifted to oxidative stress.Our previous study found that Dexmedetomidine?DEX?has a protective effect on SAKI in dogs by reducing oxidative stress injury.Therefore,SAKI model was established in this experiment and use DEX to intervene.From the perspective of inhibiting the generation of oxidative stress factors to study the regulatory mechanism of DEX on NF-?B/AP-1-iNOS/NO,and based on this,regulate the?₂-AR and I₂R to explore the target of DEX efficacy.This experiment can further improve its molecular mechanism of pharmacological action and provide theoretical basis and experimental basis for future clinical treatment of SAKI and related mechanism mechanisms.In this study,42 healthy SD rats were randomly divided into seven groups:Group C,Group L,Group W,Group D,Group A,Group I and Group Z.The rats in each group were given intraperitoneal injection of 10 mg/kg LPS.Group W and D,A,I,and Z groups were intraperitoneally injected with 15 mg/kg 1400 W and 30?g/kg DEX 30 min earlier.At 30 min before DEX injection,group A was intraperitoneally injected with 250?g/kg Atipamezole?ATI?,group I was injected intraperitoneally with 1.5 mg/kg Idazoxan?IDA?,group Z was injected intraperitoneally with 250?g/kg ATI and 1.5 mg/kg IDA,group C was injected with an equal volume of saline.Cardiac blood was collected 4 h after the molds were made,the rats were sacrificed and the kidneys were taken for reserve.We determin the protective mechanisms and efficacy of DEX on rat SAKI through renal function tests,kidney histopathological observation,oxidative stress-related factor detection,inducible nitric oxide synthase?iNOS?activity and NO content determination,a series of assays such as changes in mRNA and protein expression levels.The test results are as follows:The result of renal function tests showed that the BUN content of L group was the highest among all groups,the two groups of A and I is the second.BUN levels of W and D group was higher than that of I group?p<0.01?and group C was the lowest?p<0.01?.The serum creatinine?SCr?levels in L,A and Z groups were significantly higher than those in W group,D group and I group?p<0.01?,the level of SCr in group C was the lowest.The ratio of BUN/SCr in L,A and Z groups was significantly higher than that in W group,D group,and I group?p<0.01?,and the ratio of BUN/SCr in group W was significantly higher than that in group D and I?p<0.05?.The BUN/SCr in group C was the lowest and the ratio is within the normal range of 12:1-20:1;The levels of urinary Kidney injury molecule 1?KIM-1?in groups L,A and Z were higher than that of other groups,while the levels of urinary KIM-1 in group C were the lowest?p<0.01?compared with groups W,D and I.HE staining showed that the structure of renal tissue in group C was normal and there was no obvious pathological change in renal tubule and renal interstitium.The tubular epithelial cells in groups L,A and Z were swollen and necrotic,partial cavitation degeneration occurred,the nucleus disappeared and inflammatory cells infiltrated in the renal interstitium.In the lumen,there is a red protein like material deposit.The three groups of W,D,I were obviously improved.The swelling of renal tubular epithelial cells was reduced and the infiltration of interstitial inflammatory cells in the renal interstitium decreased.The results of oxidative stress factor test showed that the Reactive nitrogen species?RNS?content in L,A and Z groups was higher than that in other groups?p<0.01?,and the RNS in C group was significantly lower than that in D group and I group?p<0.05?,the content of RNS in group W was the lowest?p<0.01?.The levels of Malondialdehyde?MDA?in group L,group A and group Z were significantly increased?p<0.01?.The levels of MDA in group D and group I were significantly lower than that of group W?p<0.01?and the group C was the lowest?p<0.01?.The activities of superoxide dismutase?SOD?in D and I groups were significantly increased and W,A,and Z groups were significantly higher than those in C and L groups?p<0.01?.The highest concentration of glutathione?GSH?was found in group D,GSH content was significantly down-regulated in group C,group I,and group D?p<0.01?,the levels of GSH in group W were significantly higher than those in groups L,A,and Z?p<0.01?,with the lowest levels of GSH in group L.The activity of iNOS and the level of NO were detected by ELISA.The iNOS activity of L,A and Z groups was significantly increased?p<0.01?.Excess NO was one of the inducing factors of microcirculation disturbance and oxidative stress injury.NO levels in L,A and Z groups were significantly increased compared with other groups?p<0.01?,and NO levels in W,D and I groups were significantly decreased higher than C group?p<0.05?.Real-time PCR results display that the expressions of c-Jun mRNA,c-Fos mRNA,NF-?B mRNA and iNOS mRNA in L,W,A and Z groups were significantly increased compared with other groups?p<0.01?.Western Blot analysis showed that the expressions of c-Jun,c-Fos,p-I?B/I?B and p-NF-?B in L,W,A,and Z groups were significantly higher than that in other groups.The expression of c-Jun protein in group I was the lowest?p<0.01?.The expression of c-Fos protein was the lowest in group C?p<0.01?.The results of this study indicate that a large amount of NO accumulated in rats can stimulate the body to produce RNS and cause oxidative stress injury,which plays an important role in LPS induced SAKI in rats.DEX can reverse LPS-induced SAKI in rats by alleviating the oxidative stress injury in the body.DEX can down-regulate the mRNA expression of NF-?B/AP-1,inhibit the iNOS activity,reduce the release of NO,reduce oxidative stress factors in sepsis rats,improve oxidative stress and reduce AKI induced by sepsis.