title: N-acetylcysteine attenuates cardiopulmonary bypass-induced lung injury in dogs.
abstract: BACKGROUND
  Cardiopulmonary bypass (CPB) is usually associated with inflammatory response that leads to various degrees of organ dysfunction in multiple systems, including lung injury. Our previous study showed that transforming growth factor beta1 (TGFβ1) was involved in CPB-induced lung injury. N-acetylcysteine (NAC) is an antioxidant and is able to prevent CPB-induced pneumocyte apoptosis through scavenging radical. Therefore, we investigated whether NAC may attenuate CPB-induced lung injury by inhibiting TGFβ1 expression.
  
  
  METHODS
  Fifty-four 18 to 24-month-old mongrel dogs (15-16 kg) were randomly divided into control group, CPB group and NAC group (n = 18). Six dogs in each group were killed prior to, as well as 30 and 60 minutes after the operation (T0, T1 and T2). Lung injury was evaluated by hematoxylin and eosin (H&E) staining. Respiratory index (RI), oxygenation index (OI), malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the lung were determined at each time point. TGFβ1 expression was determined using real time RT-PCR and immunohistochemistry.
  
  
  RESULTS
  A serious lung injury was observed after CPB in dogs. RI and MDA content were increased significantly after CPB, whereas OI and SOD activity were decreased. H&E staining showed that NAC treatment obviously attenuated CPB-induced lung injury. NAC treatment upregulated OI and SOD activity and downregulated RI and MDA content in the lung tissues of dogs after CPB. Treatment with NAC significantly suppressed the TGFβ1 expression in the lung tissues at both mRNA and protein levels.
  
  
  CONCLUSIONS
  Our results suggest that NAC is a potent agent against CPB-induced acute lung injury through inhibiting TGFβ1 expression.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Qu
authors.forename: Qianyu
authors.initials: Q
authors.lastname: Li
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Wang
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Yang
authors.forename: Dongguo
authors.initials: D
authors.lastname: Wang
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D055371:Acute Lung Injury / Q000188:drug therapy* / Q000209:etiology; D000818:Animals; D002315:Cardiopulmonary Bypass / Q000009:adverse effects* / Q000379:methods; D004285:Dogs; D007150:Immunohistochemistry; D008168:Lung / Q000378:metabolism / Q000473:pathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053773:Transforming Growth Factor beta1 / Q000187:drug effects / Q000378:metabolism*
chemical_list: D053773:Transforming Growth Factor beta1; D000111:Acetylcysteine