['The warm ischemic period in non-heart-beating donor lungs may contribute to a higher degree of ischemia-reperfusion injury after lung transplantation. We investigated the impact and timing of administration of N-acetyl cysteine (NAC) on inflammatory parameters.', 'Ischemia (I) was induced by clamping the hilum of the left lung for 90 minutes, and some protocols were followed by reperfusion (R) for 4 hours. Mice were divided into nine groups (n = 6/group): three control groups ([sham] (thoracotomy only), [I] and [I+R]); two groups with saline instillation only ([saline+I] and [saline+I+R]); and four experimental groups with NAC (50 mg/kg), administered by instillation ([NAC+I], [NAC+I+R] and [I+NAC+R]) or by aerosol ([NACaero+I+R]). Cell counts and protein levels in bronchoalveolar lavage (BAL) were determined.', 'NAC administered prior to hilar clamping led to a significant decrease in macrophages and lymphocytes and interleukin (IL)-1 beta levels after ischemia. NAC also resulted in significantly fewer macrophages, lymphocytes and neutrophils as well as IL-1 beta, keratinocyte cytokine (KC), monocyte chemoattractant protein (MCP)-1 and IL-6 levels in BAL taken after reperfusion.'] Does n-acetyl cysteine pre-treatment attenuate inflammatory changes in the warm ischemic murine lung?