The Effects Of Dexmedetomidine On Glomerular Endothelial Glycocalyx During Kidney Ischemia-reperfusion Injury In Rats

ObjectiveTo explore the effect of dexmedetomidine on glomerular endothelial glycocalyx during kidney ischemia-reperfusion injury in rats and its possible mechanism.MethodsTwenty eight adult male Sprague-Dawley rats were randomly divided into four groups(n = 7 each): sham group(group S),sham + dexmedetomidine group(group SD),ischemia-reperfusion group(group R)and ischemia-reperfusion +dexmedetomidine group(group RD).Dexmedetomidine was intraperitoneal injected with a dose of 25 ?g/kg when 30 min before operation in groups SD and RD,and the same volume of saline was injected in groups S and R,respectively.Sham operation was conducted in groups S and SD,and 45 min of ischemia followed by 24 hours reperfusion in groups R and RD.After 24 hours,levels of serum creatinine(Scr)and blood urea nitrogen(Bun)and kidney tissue histopathology were evaluated.The glomerular endothelial glycocalyx was visualized by transmission electron microscopy and confocal microscopy.Levels of Syndecan-1,Heparanase-1 and Tie2 were measured in kidney tissues.ResultsCompared with group S,blood Scr and Bun were significantly increased(P <0.05),kidney tissue histopathology injury was significantly aggravated,the structure of the glomerular endothelial glycocalyx was significantly damaged under electron microscopy and confocal microscopy,the expression levels of Syndecan-1 and Tie2 in kidney tissue were significantly decreased(P < 0.05),and the expression level of Heparanas-1 was significantly increased(P < 0.05)in group R.Compared with group R,blood Scr and Bun were significantly reduced(P < 0.05),kidney tissue histopathology injury was significantly alleviated,the structure destruction of the glomerular endothelial glycocalyx was significantly reduced under electron microscopy and confocal microscopy,the expression levels of Syndecan-1 and Tie2 in kidney tissue were significantly increased(P < 0.05),and the expression level of Heparanase-1 was significantly reduced(P < 0.05)in group RD.ConclusionDexmedetomidine-pretreatment attenuates kidney ischemia-reperfusion injury in rats maybe through protecting and restoring the glomerular endothelial glycocalyx.The renoprotective effects are probably related to Heparanase-1 inhibition and Tie2 activation.