ABSTRACT
Objective To explore whether dexmedetomidine(Dex)could mitigate acute lung in-jury induced by hind limb ischemia reperfusion(I/R).Methods One hundred and twenty SD rat weigh-ting 250-300 g were allocated to receive hind limb I/R,I/R plus Dex (25 μg/kg Dex was intraperitoneal in-jection 30 min before ischemia)and norm control group,and each group was further divided into five sub-groups:before operation and 4 h ischemia followed by 0,1,3 and 6 h reperfusion.After euthanization,lung W/D weight ratio,PaO2 ,SOD,MDA and TNF-α were determined.Results Compared with group C, hind limb I/R injury significantly increased serum TNF-α concentration and W/D ratio,with significantly decreasing PaO2 level at any time of reperfusion in the group I/R,the concentration of MDA increased and the SOD activity decresed at 1,3,6 h of reperfusion.Conversely,W/D ratio as well as the concentration of TNF-αin the serum of the I/R plus group Dex were significantly lower than those of the I/R at 6 h of reperfusion,PaO2 level increased respectively;the concentration of MDA decresed at 1,3,6 h of reperfusion and the SOD activity increased at 3,6 h of reperfusion in I/R plus group Dex.Conclusion Dex mitigates a-cute lung injury induced by unilateral hind limb I/R in rats.The mechanisms may involve attenuating oxida-tive stress and inhibiting inflammatory response.