RESUMO
Nitric oxide (.NO) attenuates hydrogen peroxide (H(2)O(2))-mediated barrier dysfunction in cultured porcine pulmonary artery endothelial cells (PAEC) (Gupta MP, Ober MD, Patterson C, Al-Hassani M, Natarajan V, and Hart, CM. Am J Physiol Lung Cell Mol Physiol 280: L116-L126, 2001). However,.NO rapidly combines with superoxide (O) to form the powerful oxidant peroxynitrite (ONOO(-)), which we hypothesized would cause PAEC monolayer barrier dysfunction. To test this hypothesis, we treated PAEC with ONOO(-) (500 microM) or 3-morpholinosydnonimine hydrochloride (SIN-1; 1-500 microM). SIN-1-mediated ONOO(-) formation was confirmed by monitoring the oxidation of dihydrorhodamine 123 to rhodamine. Both ONOO(-) and SIN-1 increased albumin clearance (P < 0.05) in the absence of cytotoxicity and altered the architecture of the cytoskeletal proteins actin and beta-catenin as detected by immunofluorescent confocal imaging. ONOO(-)-induced barrier dysfunction was partially reversible and was attenuated by cysteine. Both ONOO(-) and SIN-1 nitrated tyrosine residues, including those on beta-catenin and actin, and oxidized proteins in PAEC. The introduction of actin treated with ONOO(-) into PAEC monolayers via liposomes also resulted in barrier dysfunction. These results indicate that ONOO(-) directly alters endothelial cytoskeletal proteins, leading to barrier dysfunction.
Assuntos
Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Molsidomina/farmacologia , Nitratos/farmacologia , Óxido Nítrico/fisiologia , Transativadores , Tirosina/análogos & derivados , Actinas/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Proteínas do Citoesqueleto/metabolismo , Endotélio Vascular/citologia , Cinética , Molsidomina/análogos & derivados , Doadores de Óxido Nítrico/farmacologia , Oxidantes/farmacologia , Artéria Pulmonar , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/farmacologia , Suínos , Tirosina/metabolismo , beta CateninaRESUMO
Use of several bronchoscopic techniques can lead to the rapid and noninvasive diagnosis of many infectious and inflammatory diseases. As these and newer techniques become more widespread, bronchoscopy will continue to be an integral component of the workup of these diseases.