Effect of dexmedetomidine on scalds-induced acute lung injury in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of dexmedetomidine on acute lung injury induced by scalds in rats.Methods Seventy-five male Sprague-Dawley rats,weighing 200-220 g,were randomly divided into 5 groups (n =15 each) using a random number tablecontrol group (group C),scald group (group S),dexmedetomidine group (group D),α-bungarotoxin (α-BGT) group,and dexmedetomidine+ α-BGT group (group D+α-BGT).About 30％ of the total body surface was shaved and then exposed to 98 ℃ water for 12 s in S,D,α-BGT and D+α-BGT groups.The back of rats was exposed to 37 ℃ water for 12 s in group C.Rats were resuscitated with lactated Ringer's solution injected intraperitoneally according to Parkland formula within 24 h after establishment of the model.In D,α-BGT,and D+α-BGT groups,dexrnedetomidine 40 μg/kg,α7 nicotinic acetylcholine receptor antagonist α-BGT 1 μg/kg,and α-BGT 1 μg/kg plus dexmedetomidine 40 μg/kg were injected intraperitoneally,respectively,at 15 min before establishnent of the model.At 24 h after establishment of the model,the rats were sacrificed,and lungs were removed for examination of the pathological changes and for determination of myeloperoxidase (MPO) activity,in terleukin-1beta (IL-1β),tumor necrosis factor-alpha (TNF-α),and IL-6 contents (by enzyme-linked immunosorbent assay),and nucleoprotein factor kappa B (NF-κB) (by Western blot).The lung water content [(wet weight-dry weight)÷wet weight× 100％] was calculated.Results Compared with group C,the lung water content,MPO activities,and contents of IL-1β,TNF-α and IL-6 were significantly increased,and the expression of NF-κB was up-regulated in S,α-BGT and D groups (P＜0.05).Compared with group S,the lung water content,MPO activities,and contents of IL-1β,TNF-α and IL-6 were significantly decreased,and the expression of NF-κB was down-regulated in D and D+α-BGT groups (P＜0.05),and no significant change was found in the parameters mentioned above (P＞0.05),and the pathological changes were significantly attenuated in group α-BGT.Compared with group D,the lung water content,MPO activities,and contents of IL-1β,TNF-α and IL-6 were significantly increased,the expression of NF-κB was up-regulated (P＜0.05),and the pathological changes were aggravated in group D + α-BGT.Conclusion Dexmedetomidine can mitigate scalds-induced acute lung injury in rats.