급성 폐손상 동물모델에서 aquaporin 수분통로의 발현

Abstract

Background : Aquaporins (AQPs) may play a role in the pathogenesis of pulmonary inflammation and edema. This study investigated the role ofAQPs in acute lung injury following bleomycin inhalation in rats. Methods : Sprague-Dawley rats were treated via inhalation with 10 U/kg bleomycin hydrochloride dissolved in 5 ml of normal saline. The control rats were treated with 5 ml normal saline. The animals (n = 6-8 rats per group) were sacrificed at 4, 7, and 14 d. The changes in AQP1, AQP4, and AQP5 expression levels over time were analyzed by Western blotting. The nitrate and nitrite concentrations in the bronchoalveolar lavage fluid (BALF) were measured using a modified Griess reaction. ELISA was used to check cytokines. Results : The respiration rates were significantly higher 4 and 7 days after the bleomycin treatment compared with those of the control rats. The tidal volume was lower in rats at 4 days after the bleomycin treatment, and the wet/dry weights of the lung were significantly higher than those of the control group. The nitrite and nitrate concentrations in the BALF from the rats at 4 days after exposure to bleomycin were greater than those from the saline-treated rats. Immunoblotting studies demonstrated that the AQP1 and AQP4 expression levels were lower in the rats at 4 days. However, the AQP4 expression level was higher at 7 days. The AQP5 expression level increased at 4, 7 and 14 days after the bleomycin treatment. Conclusion : This study demonstrates that AQPs are expressed differently in bleomycin-induced pulmonary edema.