羟乙基淀粉对内毒素大鼠急性肺损伤的效果观察

The effects of hydroxyethyl starch on acute lung injury in endotoxemic rats

目的观察不同剂量6%羟乙基淀粉(HES)持续静脉输注后对内毒素(LPS)感染大鼠急性肺损伤(ALI)的保护作用。方法健康雄性SD大鼠50只,随机分成5组(n=10),A1-A3组、B组及C组(空白对照组),A1-A3组和B组右侧股静脉注入LPS(5mg/kg),1分钟后分别从右侧颈内静脉持续输注HES 3.75、7.5、15ml/kg和NS 7.5ml/kg;致伤4小时后观察肺组织大体标本和光镜、电镜下的病理学变化。结果C组肺组织形态大小正常,呈粉红色,无充血、出血、肿胀;光镜下肺组织结构清晰,无明显病理改变;电镜下气血屏障连续完整,血管内皮细胞形态正常,毛细血管基底膜完整均匀。B组肺表面湿润,肺组织弥漫性充血肿胀,体积明显增大,呈暗红色;光镜下肺组织毛细血管明显扩张、充血,肺泡腔中可见渗出液、红细胞(RBC),游出的多形核粒细胞(PMN),部分肺泡腔萎陷不张;电镜下肺组织超微结构明显受损,气血屏障结构模糊,血管内皮基底膜断裂,增厚不均匀。A1-A3组病理学损伤不如B组明显,尤其是A2组肺损伤程度最轻。结论不同剂量6%HES对LPS感染大鼠急性肺损伤均有保护,以HES 7.5ml/kg的效应最佳。

Objective To observe the protective effect of different doses of hydroxyethyl starch on acute lung injury （ALI） in endotoxemic rats. Methods Fifty healthy male SD rats weighing 250 - 300g were randomly divided into 5 groups with 10 animals in each group： in group A1 -A3, 1 min after lipopolysaccharide （LPS 5mg·kg^-1） injected from right femoral vein, 6% HES （200/0.5） 3.75ml·kg^-1 ,7.5ml·kg^-1 ,15ml·kg^-1 were infused intravenous respectively at a rate of 0.2ml·ml^-1 from right internal jugular vein; group B received LPS 5mg·kg^-1 and 0.9% N. S 7.5ml ·kg^-1 ; Group C served as control one. Four hours later, macroscopically changes were also observed and microstructure was studied further with light and electronic microscope. Results In group C, the shape and size of lung were normal. They were pink without congestion, bleeding and swelling. The lung structure was clear and lack of pathological changes under the light microscope. The air - blood barrier was successive and integrated, the shape of vascular endothelial cell was normal, the capillary basement membrane was completed and uniform under the electric microscope. In group B, the lung appearances was kermesinus and moistens, the lung tissue was extensively bleeding and swelling; the size of lung was enlarged obviously. The lung blood capillary was significantly expanded and congested. There were diffused, RBC, and emigrated PMN in alveolar space combined with some collapsed pulmonary alveoli under the light microscope. The air - blood barrier was obviously injured and unclear, the capillary basement membrane was broken and uneven, and the construction of vascular endothelial cell was injured under the electric microscope. Histopathological damages of lung in group A1 -A3 were severe less than that in group B. Especially 6% HES（200/0.5） 7.5ml ·kg^-1 had the most significant effects to inhibited damages in acute lung injury. Conclusion The different doses of 6% HES （200/0.5） can significantly reduce ALI in endotoxemic rats and the protective effect of HES 7.5ml·kg^-1 is best.