Lung injury following pulmonary resection in the isolated, blood-perfused rat lung

Lung resection mag be complicated by postpneumonectomy pulmonary oedema. Ox idant generation following surgery-induced ischaemia-reperfusion may be res ponsible. This hypothesis was tested utilizing isolated, in situ, blood perfused rode nt lungs subjected to continuous perfusion (control subjects); one lung ven tilation followed by pneumonectomy (group 1); or one lung ventilation follo wed by reinflation of the collapsed lung (group 2). In control subjects, no significant changes in markers of oxidant damage, o xygenation, pulmonary artery pressure or extravascular albumin extravasatio n were detected. In group 1 lungs, hydroxyl radical-like damage was detecte d in association with impaired oxygenation (p<0.05), and increased pulmonar y artery pressure and extravascular albumin accumulation in both lungs. In group 2, there,vas evidence of hydroxyl radical-like damage, and a fall in oxygenation (p<0.05) occurred during one lung ventilation. There was a tran sient rise in pulmonary artery pressure following lung reinflation and extr a vascular albumin accumulation was significantly increased in both lungs ( right>left, p<0.05). Both changes were attenuated (p<0.05) following treatm ent with the reactive oxygen species (ROS) scavenger superoxide dismutase ( group 2a) and the nitric oxide synthase inhibitor N-G-nitro-L-arginine meth yl ester (group 2b). Hydroxyl radical-like damage was undetectable followin g nitric oxide synthase inhibition. Oxidant stress may contribute to the pathologies seen in this model of lung injury.