N-acetylcysteine attenuates lung ischemia-reperfusion injury after lung transplantation

Background. Early acute graft dysfunction continues to be a problem after lung transplantation and results in significant postoperative morbidity and mortality. This study assessed the protective effect of N-acetylcysteine (NAC) on posttransplant lung ischemia - reperfusion injury. Methods. Rat single-lung transplantation was performed in two experimental groups ( n = 5) after 18 hours of cold ( 4 C) ischemia. Group I was the ischemic control (IC) group. In group II ( NAC), donor and recipient animals were treated with an intraperitoneal injection of 150 mg/kg NAC 15 minutes before harvest, and recipient animals were treated again before reperfusion. After 2 hours of reperfusion, oxygenation was measured. Lung tissue was assessed for lipid peroxidation, neutrophil infiltration, and reduced glutathione level. Peak airway pressure was recorded throughout the reperfusion period. Results. Rats treated with NAC showed significantly better oxygenation (184.5 +/- 83.3 mm Hg versus 67.3 +/- 16.4 mm Hg, p = 0.016) and reduced lipid peroxidation (7.34 +/- 1.9 mu mol/g versus 17.46 +/- 10.6 mu mol/ g, p = 0.016). Lung tissue reduced glutathione levels were 6.8 +/- 0.9 mu M in the IC group and 20.6 +/- 2.4 mu M in the NAC group ( p = 0.004). Peak airway pressure at the end of the reperfusion period was 14.4 +/- 1.6 cm H2O in the NAC group, and 19.2 +/- 2.2 cm H2O in the IC group ( p = 0.008). Myeloperoxidase activity and the ratio of wet-to-dry weight did not differ between the groups. Conclusions. In this model, exogenously administered NAC effectively protected the lungs from reperfusion injury after prolonged ischemia.