[Effects of dexamethasone on acute lung injury in rats induced by lipopolysacharide].
OBJECTIVE
To study the difference between the preventive and therapeutic effects of dexamethasone on acute lung injury models induced by lipopolysacharide (LPS) in different phases.


METHODS
Forty adult male Wistar rats were randomly divided into four groups: (1)control group to receive intraperitoneal NS injection (2 mL/kg). (2)LPS group to receive intraperitoneal LPS injection (5 mg/kg). (3)one-hour group to receive intraperitoneal dexamethasone injection (2 mg/kg) one hour after LPS injection. (4)three-hour group to receive intraperitoneal dexamethasone injection (2 mg/kg) three hours after LPS injection. Then histopathology, arterial blood gases, lung permeability, wet-to-dry weight ratio and immunohistochemistry AQP1 were performed 24 hours later.


RESULTS
Dexamethasone could improve biological indexes. Lung permeability, wet-to-dry weight ratio and immunohistochemistry AQP1 were (5.73+/-1.37), (4.92+/-0.23), (19.92+/-6.47) in LPS group, (2.4+/-0.51), (4.89+/-0.21), (33.47+/-9.41) in one-hour group and (2.15+/-0.63), (4.57+/-0.14), (40.69+/-9.18) in three-hour group, respectively. Dates in three-hour group were prior to those of one-hour group, and there was slight but no significant difference between the two groups.


CONCLUSIONS
Dexamethasone can improve lung permeability and reduce lung edema. There is no need to be treated with glucocorticoids in advance.
Lin
Qin
Q
Department of Respiratory, Peking University First Hospital, Beijing 100034, China.
Wang
Guang-fa
GF
Tang
Xiu-ying
XY
Zou
Shui-lan
SL
D000208:Acute Disease; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000627:therapeutic use; D051398:Aquaporin 1 / Q000032:analysis; D003907:Dexamethasone / Q000008:administration & dosage / Q000627:therapeutic use*; D007150:Immunohistochemistry; D007274:Injections, Intraperitoneal; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000633:toxicity; D008168:Lung / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008171:Lung Diseases / Q000139:chemically induced / Q000188:drug therapy*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
D000893:Anti-Inflammatory Agents; C496022:Aqp1 protein, rat; D008070:Lipopolysaccharides; D051398:Aquaporin 1; D003907:Dexamethasone