地塞米松预治疗对失血性休克犬肺Ⅱ型上皮细胞保护作用的电镜观察

杂种犬10只,随机分为失血性休克组(HS)和失血性休克地塞米松预治疗组(HS-D)。放血至血压降至并维持于5.3～6.6kPa (40～50mmHg),放血后5小时处死动物,取肺组织进行光镜与电镜观察。结果表明:HS组,光镜下显示弥散性肺不张,间质水肿。电镜观察发现,肺Ⅱ型上皮细胞严重受损,核皱缩;线粒体肿胀,嵴断裂、消失;粗面内质网扩张;多聚核糖体解聚;板层小体明显变形,其膜板有的融合或破坏。HS-D组无论光镜还是电镜观察结果均显著地轻于HS组。证明地塞米松预治疗对肺Ⅱ型上皮细胞具有明显的保护作用。

Electron microscopic observation of protective efffect of dexamethasone pretreatment on type Ⅱ epicytes in lungs of dogs subjected to hemorrhagic shock

Ten dogs made hemorrhagically shocedk experimentally were randomly divi-ded into a dexamethasone pretreated group (HS-D) and a nonpretreated group (HS) .Arterial blood pressure was kept 40-50 mm Hg by bleeding and infu-sion for 5 hours.The dogs were killed and the lungs were observed. In HS group disseminated collapse of the lungs and interstitial swelling were observed micro-scopically.Severe damage of type II epicytes, such as shrinking of the nuclei, mitochondrial swelling with breakage and disappearance of the crests, distention of the rough endoplasmic reticulum, depolymerization of polyribosomes, appar-ent transformation of Osmiophillic multiamillary bodies with fusion or distruction of the membranous lamina,was observed under the electron microscope. However, in HS-D group all these changes observed either microscopically or under the electron microscope were less significant than that in HS group.These results proved that dexamethasone pretreatment exerted an obvious protective effect on type II epicytes in lungs of dogs subjected to hemorrhagic shock.