谷氨酰胺不同时点给药对内毒素致大鼠急性肺损伤的影响

Effect of glutamine administered at different times on endotoxin-induced acute lung injury in rats

目的:观察不同时点给予谷氨酰胺对内毒素致大鼠急性肺损伤的影响。方法:静脉注射脂多糖(LPS)5mg/kg复制大鼠急性肺损伤模型。雄性SD大鼠80只,随机分为5组:对照组(C组);LPS组(L组);G1,G2,G3组为谷氨酰胺+LPS组,分别于LPS注入前1h、LPS注入即刻、LPS注入后1h静脉注射谷氨酰胺0.75g/kg。所有动物于注射LPS4h后颈动脉放血处死,取肺组织测定肺湿/干重比、肺组织TNF-α蛋白水平、伊文斯蓝含量。光镜下观察肺组织形态学变化,透射电镜下观察肺组织超微结构变化。结果:G1组和G2组肺湿/干重比、伊文斯蓝含量、肺组织TNF-α蛋白水平较L组明显下降,光镜下肺组织结构及透射电镜下肺组织超微结构明显改善;G3组上述指标变化与L组相似。结论:谷氨酰胺早期给药可降低内毒素所致急性肺损伤肺泡毛细血管膜的通透性,使肺组织病理损伤减轻。

Objective：To investigate the effect of glutamine administered at different times on endotoxin-induced acute lung injury in rats. Methods：Eighty male SD rats were randomly assigned to receive normal saline in group C,5 mg/kg of lipopolysaccharide （LPS） in group L,0.75 g/kg of glutamine and then 5 mg/kg of LPS 1 hour later in group G1,0.75 g/kg of glutamine and 5 mg/kg of LPS simultaneously in group G2,and 5 mg/kg of LPS and then 0.75 g/kg of glutamine 1 hour later in group G3,respectively. The rats were killed 4 hours after the injection of LPS. The lungs were sampled,and the lung wet/dry weight ratio,the level of tumor necrosis factor-α（TNF-α）,and the content of Evans blue were determined. The changes in lung morphology and ultrastructure were observed under light microscope and transmission electron microscope,respectively. Results：Compared with group L,the lung wet/dry weight ratio,the level of TNF-α,and the content of Evans blue significantly decreased and the changes in lung morphology and ultrastructure were less severe in groups G1 and G2. Conclusion：Early administration of glutamine could ameliorate acute lung injury induced by endotoxin.