l-arginine and pentoxifylline attenuate endothelial dysfunction after lung reperfusion injury in the rabbit

Background. Among the factors involved in the early complications of lung transplantation is the ischemiareperfusion syndrome related to a warm reperfusion in ischemic lungs. Methods. Using an isolated rabbit lung preparation perfused with whole blood, we studied the effects of cold ischemia followed by a warm reperfusion on pulmonary vascular responses to reproduce experimentally the conditions encountered during lung transplantation. Results. Pulmonary vascular responses to acetylcholine were rapidly altered by warm ischemia (relaxation of 7% versus 60% in controls). Conversely, relaxation was maintained even after a prolonged cold ischemic storage (maximal relaxation of 57% at 48 hours). Warm reperfusion in ischemic lungs induced major alteration of endothelium-dependent relaxation (maximal relaxation of 13% at 4 hours). The addition of l-arginine or pentoxifylline during reperfusion prevented the pulmonary endothelial alteration resulting from warm reperfusion. Conclusion. These data suggest that treatments aimed at maintaining intact functional endothelium reduce ischemia-reperfusion injury in transplanted lungs.