L-ARGININE AND PENTOXIFYLLINE ATTENUATE ENDOTHELIAL DYSFUNCTION AFTERLUNG REPERFUSION INJURY IN THE RABBIT

Background. Among the factors involved in the early complications of l ung transplantation is the ischemia-reperfusion 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 res ponses to reproduce experimentally the conditions encountered during l ung transplantation. Results. Pulmonary vascular responses to acetylch oline were rapidly altered by warm ischemia (relaxation of 7% versus 6 0% in controls). Conversely, relaxation was maintained even after a pr olonged cold ischemic storage (maximal relaxation of: 57% at 48 hours) . Warm reperfusion in ischemic lungs induced major alteration of endot helium-dependent relaxation (maximal relaxation of 13% at 4 hours). Th e addition of L-arginine or pentoxifylline during reperfusion prevente d 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 tr ansplanted lungs.