脓毒症大鼠肺血管内皮细胞、细胞间粘附分子1和E-选择素的变化及其意义

摘要

Objective:To observe the changes and significance of pulmonary vascular endothelial cells (VEC),ICAM-1 and E-selectin in sepsis rats.Methods:60 SD rats were randomly divided into 2 groups:the control group and the sepsis group.The sepsis model was prepared by injection of lipopolysaccharide(4 mg/kg).The expression of ICAM-1 and E-selectin in pulmonary VEC of rats was detected by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical method.The VEC apoptosis in lung was analyzed with Hoechest-33258 staining.The ultramicrostructure of pulmonary VEC was observed under electron microscope.Results:Compared with the control group,the expression of ICAM-1 was significantly increased in the sepsis group (P<0.01),the expression of ICAM-1 was increased gradually and achieved the peak value at 24 h.The expression of E-selectin was achieved the peak value at 6 h and decreased gradually during 24 h.The apoptosis and necrosis of pulmonary VEC was increased gradually and achieved the peak value at 24 h (P<0.01).Conclusion:The expression of ICAM-1 and E-selectin in sepsis rats is significantly increased,probably leading to both necrosis and apoptosis of pulmonary VEC,resulting in the occurrence of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS).%目的:观察脓毒症大鼠肺血管内皮细胞(VEC)、细胞间黏附分子1和E-选择素的变化特点并探讨其意义.方法:60只SD大鼠随机分成对照组和脓毒症组.以脂多糖(LPS)静脉注射制备大鼠脓毒症模型,采用逆转录聚合酶链反应(RT-PCR)和免疫组织化学方法研究ICAM-1和E-选择素的表达;用Hoechest染色评价肺VEC凋亡;用电子显微镜观察肺VEC.结果:脓毒症组大鼠肺ICAM-1 mRNA和ICAM-1蛋白的表达与对照组比较明显增加(P<0.01),脓毒症组ICAM-1 mRNA和ICAM-1蛋白的表达6小时增高,24小时达到高峰;E-选择素表达6小时达高峰,以后逐渐下降,24小时后降至对照组相同水平.脓毒症组肺VEC随着制模时间的延长,坏死和凋亡显著增加(P<0.01),电子显微镜观察也得到证实.结论:脓毒症大鼠肺ICAM-1和E-选择素的表达明显增加,可能导致肺VEC的坏死和凋亡以及急性肺损伤(ALI)和急性呼吸窘迫综合征(ARDS)的发生.