慢性阻塞性肺疾病早期急性肺损伤对血管内皮形态的影响

目的观察慢性阻塞性肺疾病(COPD)大鼠模型造模早期急性肺损伤(ALI)对血管内皮形态的影响。方法健康雄性Wistar大鼠48只,随机分为空白组24只,COPD模型组24只。用气管内注入脂多糖(LPS)及烟熏方法制作COPD模型。分别于第2、15、28天随机处死模型组及空白组大鼠各8只进行血管内皮形态学观察。结果与空白组比较,光学显微镜下COPD模型组造模第2天部分血管壁不光滑,周围可见散在中性粒细胞及淋巴细胞浸润,少量肺间质血管可见充血;造模第15天则出现血管扩张,形态不规则,血管平滑肌不均匀,血管间质增生;造模第28天血管平滑肌增生明显,几乎占据整个血管管壁,周围有大量炎症细胞浸润。电子显微镜下COPD模型组造模第2天肺微小动脉及毛细血管内皮细胞结构基本正常,少数线粒体出现水肿;造模第15天内皮细胞间联结断裂,基底膜不完整,细胞质内细胞器增多,线粒体肿胀,内质网扩张,部分板层体空泡化;造模第28天肺微小动脉内皮细胞细胞质内吞饮小泡增多,线粒体出现水肿或空泡变性,肺毛细血管内皮细胞肿胀,毛细血管腔内可见多形核白细胞堵塞,板层体空泡化明显,内质网扩张明显。结论 COPD形成早期已经出现肺部血管内皮的改变,提示临床上对COPD早期急性肺血管的损伤不可忽视,为更好地制订治疗方案奠定基础。

Direct evidence of the existence of specific LPS binding sites on vascular endot helial cells

Objective:To investigate the binding characteri stics of endothelial cell (EC) with LPS free from the participation of serum fac tors. Methods:Laser confocal microscope was employed in the observat ion of the binding of EC with FITC-LPS. The KD and the binding sites of each EC were calculated by radioligand binding assay of receptors (RBA) using [ 3H] -LPS. Results:The binding of EC with LPS was saturable, time and con centration dependent and it could be competed with overdosed LPS of the same typ e. The fluorescence mainly distributed in cytoplasm, especially near the nucleus , which could also be stained. Conclusions:There might be some specific LPS binding sites exi sting on ECs and LPS could function intracellularily.