Study On The Changes And Correlation Of Alveolar Macrophages And Vascular Endothelial Cells In Early Sepsis-induced Acute Lung Injury Rats Produced By Cecal Ligation And Puncture

Objective:The study was performed to dynamicly view the changes of alveolar macrophages and the impairment of lung vascular endothelial of early sepsis-in-duced ALI rats,and to briefly discuss the correlation and possible mechanism.The sepsis-induced ALI model was produced by cecalligation and puncture(C-LP).Method: 66 SD rats,male and female informal,were randomly divided into three groups as follows:(1)normal control group(n=6);(2)sham operation group(n=30);(3)sepsis-induced ALI group(n=30). sham operation and sepsis-induced ALI group were further divided respectively into 3h,9h,24h,36h and 48h subgroups after CLP,each subgroup of sham operation and sepsis-induced ALI group had six rats.All rats were measured macrophage inflammatory protein-1α(MIP-1α) in Bronchial Alvolar Lavage Fluid;detected the changes of E-selectin,TNF-αin blood serum;observed impairment of vascular endothelial cell and TypeⅡalveolar epithelial cells using electron microscope. Calculated lung wet weight/dry weight ratio(W/D),lung index and lung water content after weighing wet weight and dry weight of lung.Results:1.The Bronchial Alvolar Lavage Fluid levels of MIP-1αobviously rised at 3 hours after CLP,significantly more than normal and sham operation group's(p<0.05),reached to peak value(1.45±0.34ng/ml) at 24 hours point,after that startd to drop down,but still exceed normal and sham operation group's(p<0.05).2.The serum levels of TNF-αin sepsis-induced ALI group after CLP was significantly higher than that of normal and sham operation group's(p<0.01),reached maxlmum(390.94±27.70pg/ml) at 24 hours point.Then,there was a downward trend,but still higher than the normal and sham operation group's(p<0.01).3.The serum level of E-selectin began to increase at 3 hours after CLP(0.26±0.02ng/ml).significantly higher than the normal and sham operation group's(p<0.05),at 24 hours point got to peak(0.40±0.01ng/ml).4. The lung wet weight/dry weight ratio,lung index and lung water content were all significantly higher than the normal group's(p<0.05) and sham operation group's(p<0.05),and kept high level. The above indicators in the sham operation group at all time points were significantly higher than the normal control group's (p<0.05).5.The damage of vascular endothelial cell and TypeⅡalveolar epithelial cells'impairments were gradually aggravated in sepsis-induced ALI model through electron microscope,and the score of vascular endothelial cell gradually rised with time-lapse.The normal function of ATⅡwas maintained by its normal form,which destroyed gradually in this experiment.6.The Bronchial Alvolar Lavage Fluid MIP-1αand serum E-selectin had obviously direct correlation.The coefficient correlation was 0.407,and F=5.557, P<0.05, the regression equation:y(MIP-1α)=0.504+1.814x(E-selectin).Conclusions:1.In the process of sepsis-induced ALI,alveolar macrophages may contribute to increase the inflammation injury of lung,and high inflammatory state increased pulmonary vascular permeability,which contribute to form pulmonary edema,all these may play an important pole in the process of sepsis-induced ALI.2.The collection of alveolar macrophages and the damages of vascular endothelial had obeviously direct correlation,which hints alveolar macrophages and vascular endothelial may play an important role in sepsis-induced ALI.