失血性休克大鼠L-选择素转录、翻译水平表达的研究

The expression of L selectin at transcription and translation level in hemorrhagic shock rat

目的 探讨失血性休克大鼠L 选择素转录及翻译水平表达对创伤及休克病理生理过程的影响。方法 大鼠剪尾取血作为正常对照 ,颈部去皮颈动脉结扎剪断插管作为实验对照 ,建立失血性休克动物模型 ;遂将其分为正常对照组、实验对照组 (创伤组 )和实验休克组 (失血性休克组 ) ,每组均为 8只。用单克隆抗体标记 ,流式细胞仪检测大鼠失血休克急性期中性粒细胞表面L 选择素的动态表达 ,以及用半定量逆转录聚合酶链反应 (RT PCR)检测大鼠白细胞胞质L 选择素mRNA半定量变化。结果 正常对照组大鼠中性粒细胞表面不同时间点L 选择素表达量 (平均荧光道数 )之间的差异无显著性 (P >0 .0 5)。与正常对照组相比 ,实验对照组细胞表面及胞质mRNA表达均上调 ,细胞表面 3h达峰值 ,4、5h持续高水平 ;mRNA进行性升高 ,于 5h达峰值。与正常对照组比 ,实验休克组两者亦均上调 ;但与创伤组比 ,3h后则呈下调趋势。结论 创伤后中性粒细胞L 选择素表达上调 ,增强白细胞 内皮细胞黏附反应 ,有助于局部创伤愈合 ,修复并抵抗感染。休克组L 选择素表达下调 ,可减少白细胞 内皮细胞过度黏附及嵌塞毛细血管 ,有助于机体疏通微循环 。

Objective To detect the expression changes of L selectin at levels of transcription and translation in hemorrhagic shock rats and to investigate the role of L selectin in pathogenesis of trauma and hemorrhagic shock.Methods The tail cut rats were set as normal group. The carotid puncture rats were set as control groups (trauma group); hemorrhagic shock model was established as shock group (hemorrhagic shock group). Every group has 8 rats. The surface expression of L selectin in neutrophils was detected in the acute phase of hemorrhagic shock by flow cytometre. The mRNA expression of L selectin was detected by reverse transcription polymerase chain reaction (RT PCR ). Results The data showed that there were quantifiable kinetic changes in leukocyte after trauma and shock. Neutrophil L selectin expression in tail cut rats showed no significant change ( P > 0.05) at different time points. The cell surface expression of L selectin and its mRNA were up regulated in controls as compared with the normal group. The peak value of surface expression was at 3rd hour and last for 4 5 hours, while the peak value of mRNA was at 5th hour. As compared with the normal group, the values in the experimental group were up regulated in the early stage ( P <0.05), while in late stage they were down regulated after 3 hours ( P <0.05). Conclusions The up regulation of L selectin in neutrophil after trauma may promote the adhesion of leucocytes to the wall of the venules and the inflammatory response may be benificial to wound healing and enhance the ability of anti infection.The down regulation of L selectin after hemorrhagic shock may be associated with alleviation effects of the excessive adhesion reaction and may improve microcirculation.