Therapeutic Effects Of Dexamethasone On Acute Lung Injury In Rats Induced By Lipopolysacharide

Objective:To evaluate the therapeutic effects of Dexamethasone(Dex) on the early period of acute lung injury in rats induced by lipopolysacharide. Methods:To form ALI model in rats,5 mg/kg of LPS were injected into rats by tail vein. After 1 h, rats were given intraperitoneal Dex injection with a dose of 10 mg/kg. one hour later, samples were collected from rats to measure lung permeability, wet-to-dry weight ratio, TNF-α, IL-8 and ICAM-1 in broncho alveolar lavage fluid(BALF), and lung histopathology was also performed, besides Dex group, control group receiving traperitoneal normal saline injection and LPS injury group were also set in the experiment. Results:lung injury in rats received Dex treatment was significantly attenuated compared with that in LPS group by histopathology. In Dex group, wet-to-dry weight ratio, PMN count, lung alveolar permeability index were significantly decreased compared with those in LPS group. No significant diference was shown between control and Dex groups in parameters mentioned above. The levels of TNF-α, IL-8 and ICAM-1 in BALF of LPS group were significantly higher than of control group. Meanwhile, no significant difference was shown between Dex and control groups at the concentrations of TNF-α, IL-8 and ICAM-1 in BALF. Conclusions:Dexamethasone can attenuate lung tissue damage and inhibit neutrophil migration to the lung and bronchoalveolar vascular leakage in the early period of ALI induced by LPS.