[Influence of lipopolysaccharide pretreatment on acute lung injury induced by lipopolysaccharide in rats].
OBJECTIVE
To evaluate the effect of lipopolysaccharide pretreatment on blocking the development of lipopolysaccharide (E.Coli O(55):B(5)) induced acute lung injury. The activity of nuclear factor-kappaB (NF-kappaB) in alveolar macrophages was assessed to elucidate its mechanism.


METHODS
Thirty-six Wistar rats were divided into three groups: normal saline (A), lipopolysaccharide (B), lipopolysaccharide preconditioning (C). Rat model of acute lung injury was reproduced by administering intraperitoneally lipopolysaccharide in a dose of 6 mg/kg. Group A and B served as control. In the test group (group C) lipopolysaccharide was given intraperitoneally 0.5 mg/kg, 0.5 mg/kg and 1.0 mg/kg consecutively for 3 days before lipopolysaccharide challenge. Four hours after lipopolysaccharide/normal saline administration, the animals were killed. Blood gas was measured. And total protein of bronchoalveolar lavage fluid (BALF) was calculated by measuring the radioactivity of (99)Tc labeled serum albumin. Wet/dry ratios of the lungs of each group were determined. The nuclear protein of the alveolar macrophages was extracted from BALF, and the activity of NF-kappaB was assayed with electrophoretic mobility shift assay (EMSA). Microscopic examination of the lung was done.


RESULTS
In group C, partial pressure of oxygen in artery (PaO(2)) was significantly higher than that in group B, and total protein content of BALF was significantly lower in group A and C than that in group B. Activity of NF-kappaB in group C was higher than group A and B.


CONCLUSIONS
Lipopolysaccharide pretreatment can reduce the severity of acute lung injury induced by lipopolysaccharide challenge. This phenomenon may be related with change in the activity of NF-kappaB of the alveolar macrophages.
Xue
Yun
Y
Department of Anesthesia, First Hospital, Peking University, Beijing 100034, China.
Wu
Xin-Min
XM
Zhang
Sheng-Suo
SS
Zhang
Xi-Zhe
XZ
Fu
Zhan-Li
ZL
Zhang
Chun-Li
CL
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D004195:Disease Models, Animal; D024202:Electrophoretic Mobility Shift Assay; D008070:Lipopolysaccharides / Q000633:toxicity*; D008168:Lung / Q000473:pathology / Q000503:physiopathology; D008297:Male; D016328:NF-kappa B / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000503:physiopathology*
D008070:Lipopolysaccharides; D016328:NF-kappa B