中国当代儿科杂志2007，Vol.9Issue(6)：521-525,5.
地塞米松对脂多糖诱导的急性肺损伤幼鼠肺泡Ⅱ型上皮细胞超微结构的影响
Effects of dexamethasone on the ultrastructure of alveolar type Ⅱ cells in young rats with lipopolysaccharide-induced acute lung injury
舒林华 1魏克伦 1薛辛东 1韩晓华 1尚云晓 1蔡栩栩 1刘春峰 1李玖军 1王丽杰1
作者信息
- 1. 中国医科大学附属盛京医院儿科,110004
- 折叠
摘要
Abstract
Objective Alveolar type Ⅱ(AT Ⅱ)cells play a crucial role in the maintenance of pulmonary surfactant homeostasis and pulmonary immunity.The effects of dexamethasone(Dex)on the ultrastructure of AT Ⅱ cells after acute lung injury remain unknown.This study focused on the ultrastructural changes caused by acute lung injury and on the effects of Dex administration on these ultrastructural changes in young rats.Methods Seventy-two 21-day-old Sprague-Dawley rats were randomly divided into control,acute lung injury and Dex-treated groups.Rats in the lung injury group were intraperitoneally injected with 4 mg/kg lipopolysaccharide(LPS)in order to induce acute lung injury,while the control rats were injected with the same amount of normal saline(NS).The Dex-treated group was injected first with LPS followed 1hr later by Dex(5 mg/kg)injection.Eight rats in each group were sacrificed 24,48 and 72 hrs after LPS or NS injection.Lung samples were obtained from the lower parts of left lungs and fixed with 2.5% glutaraldehyde for transmission electron microscope examination.Results Microvilli of AT Ⅱ cells disappeared and the number of lamellar bodies(LBs)increased in the lung injury group 24 hrs after LPS injection.The ring-like arrangement of LBs around nuclei was present until 48 hrs after LPS injection.By 48 hrs after LPS injection,giant LBs with vacuole-like abnormalities appeared.The shape of nuclei became irregular and the border of the nuclei became blurred.By 72 hrs after LPS injection,the number of LBs was obviously reduced;nucleoli disappeared;and karyolysis occurred in some of the nuclei.In contrast,in the Dextreated group,LBs crowded on one side of AT Ⅱ cells and exocytosis appeared on the same side by 24 hrs after LPS injection.By 48 hrs,the number of LBs was reduced.The number of mitochondria increased,and some of them became swollen and enlarged.However,by 72 hrs,the number of LBs increased and the ring-like arrangement of LBs around the nucleus again appeared.Conclusions Ultrastructural changes of AT Ⅱ cells following lung injury induced by LPS were time-dependent in young rats.Dex may ameliorate AT Ⅱ cell injury and promote functional restoration of AT Ⅱ cells in LPS-induced acute lung injury.关键词
脂多糖/急性肺损伤/肺泡Ⅱ型上皮细胞/板层小体/地塞米松/超微结构/大鼠Key words
Lipepolysaccharide/Acute lung injury/Alveolar type Ⅱ cell/Lamellar bodies/Dexamethasone/Ultrastructure/Rats分类
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舒林华,魏克伦,薛辛东,韩晓华,尚云晓,蔡栩栩,刘春峰,李玖军,王丽杰..地塞米松对脂多糖诱导的急性肺损伤幼鼠肺泡Ⅱ型上皮细胞超微结构的影响[J].中国当代儿科杂志,2007,9(6):521-525,5.
