Effects Of Propofol Or Etomidate Pretreatment On Lung Ischemia-reperfusion Injury

Objective：To investigate the effect of propofol and etomidate on lung ischemia-reperfusioninjury in rabbit in vivo．Methods：36healthy New Zealand male rabbits were randomly divided into four groups(n=9), sham surgery group (C), ischemia-reperfusion (IR) group, propofolpretreatment group (P) and etomidate pretreatment group (E).Group C: Chest ofrabbits was opened175min without any treatment.Group IR:Left lung hilum wasclamped for45min，after the lungs were ventilated for120min,no drug treatment；Group P:Left lung hilum was clamped for45min，after the lungs were ventilated for120min,10min before clamped left lung with blocking infusion of propofol2mg/kg.Group E:Left lung hilum was clamped for45min， after the lungs wereventilated for120min,10min before clamped left lung blocking infusion of etomidate0.9mg/kg.The left lung wet-dry weight (W/D),superoxide dismutase(SOD),malondialdehyde (MDA) and neutrophil percentage of the lavage fluid wereto be measure at the end of the experiment. we observe the pathology change of leftlung tissue by HE staining and the apoptosis cell of left lung tissue.Results:1、Changes of lung W/D ratio: Take the left lung tissue at2h after perfusion.TheW/D ratio of left lung in group IR was signifigantly higher than group C、group Pand group E (P<0.05). Compared with group P and group E, the W/D ratio of leftlung was signifigantly lower in group C(P<0.05);There was no significant distinctbetween group P and group E(P>0.05).2、SOD activity and MDA content:The SOD activity and MDA content of rabbitblood samples are not significantly different in each group on basis state, （P>0.05）.Ischemia45min, The SOD activity of group IR is obviously lower thanthe other three groups (P<0.05).The group P and group E are lower than C group (P <0.05),there is no significant difference between group P and group E (P>0.05);TheMDA content of group IR is higher than the other three groups, without statisticaldifferences(P>0.05). The group P and group E are higher than group C,withoutstatistical differences (P>0.05).The group E is higher than group P, without statisticaldifferences(P>0.05).Perfusion2h,The SOD activity of group C were higher thangroup IR、 groupP and group E (P<0.05).The group IR is lower than group P andgroup E,without statistical differences (P>0.05).There is no significant differencebetween group P and group E(P>0.05).The MDA value of group IR is significantlyhigher than group C、 group P and group E (P<0.05).Compared with group C,theMDA value was signifigantly higher in group P and group E (P <0.05).The group Pwas lower than group E, without statistical differences(P<0.05).3、 Lung cell apoptosis:Cut the left lung tissue at2h after perfusion,Theapoptotic index of group C was significantly lower than the other three groups(P<0.05), Compared with group P and group E,the cell apoptotic index weresignificantly higher in group IR(P<0.05).There was no significant difference betweenthe group P and group E(P>0.05).4、Pathology observed cases of lung: Morphologically of alveoli is normal ingroup C,there have not red blood cells and inflammatory cells in alveoli.A lot ofalveolar collapse in group IR,there have a large number of red blood cells andinflammatory cells in alveolar.Some alveolar collapse in group P,there have some redblood cells and inflammatory cells in alveolar.Some alveolar collapse in groupE,there have some red blood cells and inflammatory cells in alveolar.The degree ofgroup P and group E are between degree of group C and group IR.5、 Neutrophil percentage of the Lavage fluid: The percentage neutrophils ofgroup IR was significantly higher than the other groups (P<0.05).Group P and groupE the percentage of neutrophils was higher than group C (P<0.05).Group P wasslightly higher than group E, without statistical differences(P>0.05).Conclusion: 1、The lungs tissue was severely destroyed in ischemia-reperfusion.2、Propofol and etomidate could protect the lungs against LIRI in rabbit in vivo,without statistical differences.