Abstract： Objective To explore the effect of glutamine on changes in the expression of intercellular adhesion molecule-1(ICAM-1)and E-selectin and the characteristics of pulmonary vascular endothelial cells(VECs)in sepsis rats.Method Totally 56 Sprague-Dawley rats were randomly divided into three groups:a control group,a sepsis group and a treatment group.All experiments were performed at the animal research center at Sun Yat-sen University in Guangzhou.Sepsis was induced by injecting 4 mg/kg lipopolysaccharide(LPS).The treatment group was injected with 4 mg/kg LPS and 0.3 g/kg glutamine.The control group was not injected with either LPS or glutamine.The rats were killed at 6,12 or 24 h after treatment and pulmonary tissue samples were obtained.The expression of ICAM-1 and E-selectin in VECs was detected by reverse transcription-polymerase chain reaction and immunohistochemistry.Apoptosis of VECs lung tissue was analyzed by Hoechest-33258 staining.The ultramicrostructure of VECs was observed under an electron microscope.Data were analyzed using analysis of variance using SPSS 13.0.Results At 6,12 and 24 h,the expression of ICAM-1 and E-selectin was significantly higher in the sepsis group(relative expression;ICAM-1:0.0864 ± 0.0101,0.141 ± 0.0147 and 0.1677 ± 0.0127,respectively;E-selectin:0.1535 ±0.0180,0.0811 ±0.0107 and 0.0505 ± 0.0031,respectively)compared with the control group(ICAM-1:0.021 ±0.0032,0.0228±0.0042 and 0.0204±0.0059,respectively;E-selectin:0.0423 ±0.0108,0.0412 ±0.0066 and 0.0418 ±0.0092,respectively)(all:P＜0.01).Glutamine treatment significantly decreased(P＜0.01)the expression of ICAM-1(0.0646±0.0136,0.1202±0.0143 and 0.1378 ±0.0085,respectively)and E-selectin(0.1071 ±0.0189,0.0628±0.0088 and0.0463±0.0049,respectively)at all time points compared with the sepsis group.However,the expression of ICAM-1 and E-selectin remained significantly higher than that in the control group(all:P＜0.05).There were similar changes in the expression of pulmonary ICAM-1,E-selectin mRNA and the results of VEC apoptosis.Electron microscopy confirmed these findings.Conclusions The expression of ICAM-1 and E-selectin was significantly increased in sepsis rats,leading to necrosis and apoptosis of VECs,and the onset of acute lung injury.Glutamine had a protective effect in VECs against lipopolysaccharide-induced sepsis.