Resumo

GABRIELLI, Luigi et al. Increased oxidative stress are associated with peripheral endothelial dysfunction and diminished vascular response to vasodilators in pulmonary hypertensive patients. Rev Chil Cardiol [online]. 2010, vol.29, n.3, pp.291-298. ISSN 0718-8560.  http://dx.doi.org/10.4067/S0718-85602010000300002.

Background: Pulmonary Arterial Hypertension (PAH) is characterized by endothelial dysfunction and vascular remodeling. Several lines of experimental evidence indícate that oxidative stress plays an important role in the pathogenesis of PAH. The role of oxidative stress and its relation with peripheral endothelial function and pulmonary vascular response to vasodilators remains unknown. Aim: To evalúate whether systemic oxidative stress and endothelial dysfunction markers are associated with the response of the pulmonary vascular bed to inhaled vasodilators in PAH patients. Methods: Cross-sectional study Fourteen patients with PAH and 14 age and gender-matched controls were in-cluded. Systemic oxidative stress was assessed through plasma malondialdehyde (MDA), xanthine oxidase (eXO) levéis and endothelial-bound superoxide dis-mutase (eSOD) activity Brachial artery endothelial-de-pendent flow-mediated vasodilation (FDD) was used to evalúate endothelial function. Right ventricular function and pulmonary vascular bed reactivity to inhaled vasodilators was determined with echocardiography in PAH patients. Results: Compared to controls, PAH patients showed impaired FDD (2.8 ± 0.6 vs 10.7% ± 0.6, p< 0.01), increased MDA and eXO levéis (0.61 ± 0.17 vs 0.34 ± 0.15μM, p<0.01 and 0.039 ± 0.005 vs 0.034 ± 0.004 U/ mL1, p=0.02 , respectively) and decreased eSOD activity 235.55 ± 23 vs 461.41 ± 33 AUC, p<0.01). Iloprost significantly improved right cardiac output (RCO) and decreased pulmonary vascular resistance. The amount of change in RCO after iloprost inhalation correlated significantly with baseline eSOD activity and FDD (Rho: 0.61, p<0.01 and Rho: 0.63, p=0.01 respectively). Conclusions: PAH patients show increased oxidative stress and endothelial dysfunction markers. Response to inhaled iloprost is closely related with baseline endothelial function and oxidative stress parameters, suggesting an important role of these elements that requires further clinical evaluation.

Palavras-chave : pulmonary artery hypertension; oxidative stress; endothelial dysfunction.

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