Dexamethasone treatment attenuates early seawater instillation-induced acute lung injury in rabbits.
There is very little evidence on the value of giving corticoids in cases of seawater drowning induced acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Therefore, this study aimed to investigate whether dexamethasone treatment can attenuate seawater instillation-induced acute lung injury in rabbits. Seawater (4 ml/kg body weight) was instilled into the lower trachea of ventilated, anesthetized rabbits. Then these rabbits were assigned randomly 20 min later to receive intravenous injection of 1mg/kg body weight of dexamethasone (dissolving in 2 ml of normal saline) or 2 ml of normal saline. All animals demonstrated immediate drops in arterial oxygen tension (PaO2) and the total thoracic compliance, which were significantly improved after 2 h of dexamethasone treatment. Histopathological study also indicated that dexamethasone treatment markedly attenuated lung histopathological changes, alveolar hemorrhage and inflammatory cells infiltration with evidence of decreasing of myeloperoxidase (MPO) activity and tumor necrosis factor-alpha (TNF-alpha) concentration in lung tissue. In addition, dexamethasone treatment reduced extravascular lung water and lung epithelial-endothelial barrier permeability, up-regulated the expression of surfactant protein-A (SP-A) and alpha-epithelial Na+ channel, and increased Na+/K+-adenosine triphosphatase (Na+/K+-ATPase) activity and Na+/K+-ATPase-alpha1 protein abundance. Thus, these data indicate that dexamethasone treatment might be of benefit in patients with seawater aspiration-induced ALI.
Xinmin
Ding
D
Department of Respiratory Disease, Naval General Hospital of PLA, Beijing 100037, China.
Yunyou
Duan
D
Chaosheng
Peng
P
Huasong
Feng
F
Pingkun
Zhou
Z
Jiguang
Meng
M
Zhiqian
Xue
X
Qinzhi
Xu
X
D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology*; D053503:Epithelial Sodium Channels; D015633:Extravascular Lung Water / Q000187:drug effects; D008168:Lung / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D010100:Oxygen / Q000097:blood; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D037662:Pulmonary Surfactant-Associated Protein A / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011817:Rabbits; D011897:Random Allocation; D012128:Respiratory Distress Syndrome / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D012623:Seawater; D015222:Sodium Channels / Q000096:biosynthesis* / Q000235:genetics; D000254:Sodium-Potassium-Exchanging ATPase / Q000096:biosynthesis* / Q000235:genetics; D015854:Up-Regulation / Q000187:drug effects
D053503:Epithelial Sodium Channels; D037662:Pulmonary Surfactant-Associated Protein A; D012333:RNA, Messenger; D015222:Sodium Channels; D003907:Dexamethasone; D000254:Sodium-Potassium-Exchanging ATPase; D010100:Oxygen