Role of angiotensinⅡin perfluoroisobutylene-induced acute lung injury in rats / 军事医学

ABSTRACT

Objective To investigate tentatively the role of angiotensionⅡ( AngⅡ) in perfluoroisobutylene ( PFIB)-in-duced acute lung injury ( ALI) in rats.Methods Twenty-eight male Wistar rats were randomly divided into one control group(0 h) and six PFIB-exposed groups which were executed at 1, 2, 4, 8, 16 and 24 h after PFIB exposure (n=4). The PFIB-exposed groups inhaled PFIB at a concentration of 145 mg/m3 for 8 min in a flow-past header while the control group was exposed to the filtered air in a similar manner .After execution at the corresponding time-point, the samples of the lung, serum and brochoalveolar lavage fluid (BALF) were harvested.The measurement of the lung wet-to-dry weight ratio ( W/D) and total protein content in BALF , and the histopathological examination of the lung were carried out to evalu -ate the degree of lung injury .The over-time changes in the content of AngⅡin the lung homogenates and blood plasma and the activity of angiotensin converting enzyme ( ACE) in the lung tissue were observed .Results The lung W/D and total protein content in BALF were increased significantly at 16 h after PFIB exposure with severe acute lung edema and abun-dant neutrophil exudation to the alveoli , which were alleviated dramatically at 24 h after PFIB exposure .The content of AngⅡin the lung homogenate showed a tendency of increase during the first 8 hours with significant decrease at 16 and 24 h after exposure.However, the content of AngⅡin the plasma and the activity of ACE in the lung experienced of fluctuations , but without significant difference compared to the control group .Conclusion There is no obvious correlation between the extent of lung injury and that of AngⅡin the lung.The pathological significance of AngⅡin PFIB-induced ALI needs to be further clarified.