The Protective Effect Of Dexmedetomidine In Rats With Renal Ischemia Reperfusion And The Impact On CXCR4 Expression

Objective:To explore the protective effect of dexmedetomidine in rat with renal ischemia reperfusion and the impact on the expression of CXCR4.Methods:SPF male SD rats(40)were randomly divided into four equal groups:sham group(group S),ischemic reperfusion group(group I/R),dexmedetomidine preconditioning group(group Pre/Dex)and dexmedetomidine post-treatment group(group Post/Dex).For group S,we lift right kidneys after anesthesia and laparotomy;We built an ischemia-reperfusion model with group I/R by cutting off the right kidney,and lefting the right one ischemia for 45min,then transfusing blood for 60min;As for group Pre/Dex,researchers made a puncture in the rats' femoral vein,and transfused 1ug/kg dexmedetomidine for 10 min,followed by infusing 0.5ug/kg dexmedetomidine until SMI;The study reperfused in the left renal of group Post/Dex,and then infused dexmedetomidine for 30 minutes.Blood sample was collected in 6 h to detect the density of creatinine and urea;ELISA was used to detect the change of content of IL-1?,TNF-a and CXCR4 in renal tissue;Histopathological changes of kidney were observed by using of pathological section and HE staining;Using ELISA and Western-blot to detect the change of CXCR4 in serum and kidney.The signification of experimental data was Mean±SD(x-±s),t-test was used as a method of comparison among groups,make statistical analysis by SPSS 13.0,P<0.05 represents significant difference.Results:Compared to group S,levels of serum creatinine and urea nitrogen in group CR and BUN had increased significantly(P<0.05);which had significant decreased in group Pre/Dex p and Post/Dex(P>0.05)compared to group I/R;while there wasn't significant difference of levels of serum creatinine and urea nitrogen in group CR and BUN between group Pre/Dex p and Post/Dex(P<0.05).Histopathological observations of kidney shows no obvious change in kidneys of group S;Serious kidney injury was found in group I/R,which showed up as obvious inflammation,tubular dilatation,congestion,edema,glomerulonephritis;While the kidney injury was significantly alleviated in group Pre/Dex and group Post/Dex,and no serious inflammatory response was detected,and unusual cellular morphology was less.Detection test shows higher content of serum IL-1? and TNF-a in group I/R?group Pre/Dex and group Post/Dex than in group S(P<0.05).Compared to group I/R,the levels of serum IL-1? and TNF-a are much lower in group Pre/Dex and Post/Dex(P<0.05).There is no significant difference between group Pre/Dex and Post/Dex(P>0.05),The detection of content of serum CXCR4 shows that,compared to group S,the content of serum CXCR4 was obviously higher in group I/R?Pre/Dex and Post/Dex(P<0.05);compared to group I/R,it is much lower in group Pre/Dex and Post/Dex(P<0.05);and the difference is not significant between group Pre/Dex and Post/Dex(P>0.05).By testing the expression level of kidney CXCR4,we found a the expression was low in group S,which is much higher in group I/R?Pre/Dex and Post/Dex,among which,group I/R expressed the most,while group Pre/Dex and Post/Dex expressed fewer.Conclusion:1.Renal ischemical reperfusion can cause renal injury which is characterized by inflammatory reaction;2.CXCR4 participates in the regulation of inflammatory cytokines in renal ischemia-reperfusion;3.Dexmedetomidine can reduce inflammatory reaction by reducing CXCR4 expression,thus alleviating renal ischemia reperfusion injury and protecting kidney to some degree.