|
|
||||||||
Department of 1Anesthesia and Critical Care; Division of Pulmonary and Critical Care Medicine, 2Department of Medicine; 3Division of Cardiac Surgery; Department of Surgery; 4Division of Cardiology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21287; and 5Center For Biomedical Electron Paramagnetic Resonance Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University College of Medicine, Columbus, Ohio
Submitted 1 December 2003 ; accepted in final form 26 March 2004
Cardiopulmonary bypass (CPB) causes acute lung injury. Reactive oxygen species (ROS) from NADPH oxidase may contribute to this injury. To determine the role of NADPH oxidase, we pretreated pigs with structurally dissimilar NADPH oxidase inhibitors. Low-dose apocynin (4-hydroxy-3-methoxy-acetophenone; 200 mg/kg, n = 6), high-dose apocynin (400 mg/kg, n = 6), or diphenyleneiodonium (DPI; 8 mg/kg) was compared with diluent (n = 8). An additional group was treated with indomethacin (10 mg/kg, n = 3). CPB was performed for 2 h with deflated lungs, complete pulmonary artery occlusion, and bronchial artery ligation to maximize lung injury. Parameters of pulmonary function were evaluated for 25 min following CPB. Blood chemiluminescence indicated neutrophil ROS production. Electron paramagnetic resonance determined the effect of apocynin and DPI on in vitro pulmonary endothelial ROS production following hypoxia-reoxygenation. Both apocynin and DPI attenuated blood chemiluminescence and post-CPB hypoxemia. At 25 min post-CPB with FIO2 = 1, arterial PO2 (PaO2) averaged 52 ± 5, 162 ± 54, 335 ± 88, and 329 ± 119 mmHg in control, low-dose apocynin, high-dose apocynin, and DPI-treated groups, respectively (P < 0.01). Indomethacin had no effect. PaO2 correlated with blood chemiluminescence measured after drug administration before CPB (R = 0.60, P < 0.005). Neither apocynin nor DPI prevented the increased tracheal pressure, plasma cytokine concentrations (tumor necrosis factor-
and IL-6), extravascular lung water, and pulmonary vascular protein permeability observed in control pigs. NADPH oxidase inhibition, but not xanthine oxidase inhibition, significantly blocked endothelial ROS generation following hypoxia-reoxygenation (P < 0.05). NADPH oxidase-derived ROS contribute to the severe hypoxemia but not to the increased cytokine generation and pulmonary vascular protein permeability, which occur following CPB.
diphenyleneiodonium; apocynin; reflection coefficient; pig; endothelium; hypoxia-reoxygenation; tumor necrosis factor; interleukin-6
This article has been cited by other articles:
![]() |
A. F. Corno Systemic venous drainage: can we help Newton? Eur. J. Cardiothorac. Surg., June 1, 2007; 31(6): 1044 - 1051. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Dodd-o, M. L. Hristopoulos, L. E. Welsh-Servinsky, C. G. Tankersley, and D. B. Pearse Strain-specific differences in sensitivity to ischemia-reperfusion lung injury in mice J Appl Physiol, May 1, 2006; 100(5): 1590 - 1595. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |