Study on peroxynitrite-induced increase in microvascular permeability in rat lungs / 中国病理生理杂志

ABSTRACT

AIM: To explore the effect of peroxynitrite (ONOO -) on pulmonary microvascular endothelial barrier and roles of ONOO - in the pathogenesis of acute lung injury in vivo. METHODS: SD rats in different groups were insufflated with various concentrations of ONOO -, decomposed ONOO - or vehicle (alkaline normal saline), respectively. Then permeability changes in pulmonary microvascular walls were detected and the pathological alterations of pulmonary tissue were examined under light microscope. Malondialdehyde(MDA) contents were measured in normal lung homogenate pretreated with various concentration of ONOO -. RESULTS: Intratracheal insufflation of ONOO - resulted in dose-dependent increase in lung coefficient, lung wet/dry ratio, lung water contents and Evans blue contents, together with significant pulmonary pathological changes such as diffuse alveolar collapse, capillary congestion, focal hemorrhage, and endothelial swollen. In addition, ONOO - can also elicit increase in MDA contents in normal lung homogenate. CONCLUSION: ONOO - may induce dysfunctions of pulmonary microvascular endothelial barriers, it is suggested that enhanced endogenous ONOO - generation may take part in the pathogenesis of acute lung injury.