The Relationship Between the NF-kappa B Activity and Anti-inflammatory Action of Surfactant in the Acute Lung Injury of Rats / 결핵

ABSTRACT

BACKGROUND: The therapeutic effects of surfactants on acute lung injury derive not only from their recruiting action on collapsed alveoli but also from their anti-inflammatory action in the alveolar space. This study evaluated the anti-inflammatory action of a surfactant in an acute lung injury model of rats by measuring the WBC count, IL-1beta and IL-6 level of bronchoalveolar lavage(BAL) fluid. In addition, neutrophils were recollected from the BAL fluid and the NF-kappa B activity of the neutrophilic nuclear protein was evaluated. METHODS: Male Sprague-Dawley rats weighing approximately 300 gram were divided into 3 groups, which consisted of 6 rats respectively. In the control group, normal saline(3ml/kg) was instilled into the trachea twice with 30 minute interval. In two other groups, acute lung injury was induced by the intra-tracheal instillation of LPS(5mg/kg). Thirty minutes later, either a surfactant(ST group; 30mg/kg) or normal saline(NT group 3ml/kg) was instilled via the trachea. Twenty-four hours after the LPS instillation, the BAL fluid was retrieved to measure the WBC count and cytokine(IL-1beta and IL-6) levels. The neutrophils were isolated from the BAL fluid and the nuclear protein was extracted to evaluate the NF-kappa Bactivity using a eletrophoretic mobility shift assay(EMSA). RESULTS: The WBC count of the BAL fluid of the ST group(3,221+/-1,914 X 10(3)/micro liter) was higher than that of the control group(356+/-275X10(3)/micro liter)(p<0.05) and lower than that of the NT group(5,561+/-1,757 X 10(3)/micro liter)(p<0.05)). The BAL fluid level of IL-1beta from the NT group(2,064+/-1,082pg/ml) was higher than those of the ST group(360+/-234pg/ml)(p<0.05) and the control group(0pg/ml)(p<0.05). The BAL fluid concentration of IL-6 from the NT group(3,621+/-567pg/ml) was also higher than those of the ST group(1,754+/-1,340pg/ml)(p<0.05) and control group(49+/-62pg/ml)(p<0.05). The NF-kappa B activity of the neutrophilic nuclear protein in the ST group and NT group was similar. CONCLUSIONS: The surfactant attenuates the alveolar inflammation in the acute lung injury of rats model. However, its anti-inflammatory action does no't appear to be mediated by the inhibition of NF-kappa B activity.