Reactive oxygen species from NADPH oxidase contribute to altered pulmonary vascular responses in piglets with chronic hypoxia-induced pulmonary hypertension

摘要

Regulation of pulmonary vascular tone is also known to differ between large, conduit level arteries and smaller, resistance level arteries (1, 2, 45). The vast majority of studies to date have evaluated the potential contribution from ROS to abnormal reactivity in larger, conduit level vessels (20, 37, 38, 53). Because of their critical role in regulating pulmonary vascular tone, it is important to identify derangements in ROS in resistance level pulmonary arteries. We previously showed that resistance level pulmonary arterial responses to acetylcho-line (ACh) are altered in newborn piglets with pulmonary hypertension induced by 3 days' exposure to hypoxia (17-19). The major purpose of this study was to test the hypothesis that ROS are involved with the aberrant responses to ACh that develop in resistance pulmonary arteries (PRAs) at this early stage of pulmonary hypertension in newborn piglets. In addition, we wanted to determine whether NADPH oxidase is an enzymatic source of ROS in the PRAs of piglets with chronic hypoxia-induced pulmonary hypertension