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。 Twelve mongrel dogs were randomly divided into hemorrhagic shock group (HS) and hemorrhagic shock dexamethasone pretreatment group (HS-D). Blood was released until the blood pressure fell to and remained at 5.3 to 6.6 kPa (40 to 50 mmHg). Animals were sacrificed 5 hours after bleeding, and lung tissues were taken for light and electron microscopy. The results showed that: HS group showed diffuse atelectasis and interstitial edema under light microscope. Electron microscopy revealed that type II epithelial cells in the lungs were severely damaged, nuclear collapse, mitochondria were swollen, hernias were broken and disappeared, rough endoplasmic reticulum was expanded, polyribosomes were depolymerized, lamellar bodies were significantly deformed, and the membranous plates were deformed. The fusion or destruction. The HS-D group was significantly lighter than the HS group regardless of light or electron microscopy. It was demonstrated that dexamethasone pretreatment significantly protects lung type II epithelial cells.