Protective Effect Of Dexmedetomidine On Endothelial Glycocalyx During Sepsis In Rat Model

ObjectiveTo investigate the protective effect of dexmedetomidine on endothelial glycocalyx during sepsis in rat acute lung injury model and it’s possible mechanism.MethodsThirty-six healthy male Sprague-Dawley rats,weighing 210-260 g,were randomly divided into three groups: a control group(Group C),a sepsis group(group S),and a dexmedetomidine group(Group D).Rats with sepsis acute lung injury were established by cecal ligation and puncture method in group S and group D.In group D,dexmedetomidine(40ug/kg)was injected intraperitoneally 30 min before modeling.Equal volume sterile saline was administered in the goup C and group S.After 24 hours,the pathological examination,arterial oxygen partial pressure and apoptotic index were observed.The contents of SOD and MDA in lung tissue were measured.The ratio of lung wet/dry weight of each group was calculated.The protein expressions of HSPE,SDC-1,ICAM-1,TNF-α,NF-κB were detected by Westerning blot.Results(1)The comparison of arterial blood gas : Compared with group C,oxygen partial pressure was decreased while carbon dioxide partial pressure was increased significantly in group S and D.Compared with group S,oxygen partial pressure was increased while carbon dioxide partial pressure was decreased in group D,the difference was statistically significant.(2)The comparison of lung wet/dry weight ratio : Compared with the group C,the wet/dry weight ratios of the lungs were significantly increased in the group S and the group D.Compared with the group S,the lung wet/dry weight ratio was significantly decreased in the group D.(3)The comparison of apoptotic index of trachea and lung tissue : Compared with group C,the apoptosis indexes were increased in group S and group D;Compared with group S,the apoptosis index was decreased significantly in group D.(4)The comparison of MDA and SOD activity :Compared with group C,the activities of SOD were decreased and the contents of MDA were increased in group S and group D;Compared with group S,the activity of SOD was increased and the content of MDA were decreased significantly in group D.(5)The comparison of protein expression: Compared with group C,the expressions of HSPE,SDC-1,ICAM-1,TNF-α and NF-κB were significantly up-regulated in group S and group D;Compared with group S,Those protein expressions were significantly down-regulated in group D.(6)The comparison of the pathological examination: No lung tissue edema and alveolar exudation in group C.A lot of exudation and inflammatory cell infiltration and pulmonary edema in group S,and light microscopy also showed the alveolar structural damage was lighter and the ammount of inflammatory cell was significantly reduced in group D.ConclusionDexmedetomidine can protect against acute lung injury by downregulating the expression of acetylsulfatase,anti-inflammatory,anti-oxidative stress,anti-apoptosis,and reducing pulmonary vascular endothelial glycocalyx lesions during sepsis.