title: The effect of post-treatment N-acetylcysteine in LPS-induced acute lung injury of rats.
abstract: BACKGROUND
  Oxidation plays an important role in acute lung injury. This study was conducted in order to elucidate the effect of repetitive post-treatment of N-acetylcysteine (NAC) in lipopolysaccaride (LPS)-induced acute lung injury (ALI) of rats.
  
  
  METHODS
  Six-week-old male Sprague-Dawley rats were divided into 4 groups. LPS (Escherichia coli 5 mg/kg) was administered intravenously via the tail vein. NAC (20 mg/kg) was injected intraperitoneally 3, 6, and 12 hours after LPS injection. Broncho-alveolar lavage fluid (BALF) and lung tissues were obtained to evaluate the ALI at 24 hours after LPS injection. The concentration of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) were measured in BALF. Nuclear factor κB (NF-κB), lipid peroxidation (LPO), and myeloperoxidase (MPO) were measured using lung tissues. Micro-computed tomography (micro-CT) images were examined in each group at 72 hours apart from the main experiments in order to observe the delayed effects of NAC.
  
  
  RESULTS
  TNF-α and IL-1β concentration in BALF were not different between LPS and NAC treatment groups. The concentration of LPO in NAC treatment group was significantly lower than that of LPS group (5.5±2.8 nmol/mL vs. 16.5±1.6 nmol/mL) (p=0.001). The activity of MPO in NAC treatment group was significantly lower than that of LPS group (6.4±1.8 unit/g vs. 11.2±6.3 unit/g, tissue) (p<0.048). The concentration of NF-κB in NAC treatment group was significantly lower than that of LPS group (0.3±0.1 ng/µL vs. 0.4±0.2 ng/µL) (p=0.0001). Micro-CT showed less extent of lung injury in NAC treatment than LPS group.
  
  
  CONCLUSIONS
  After induction of ALI with lipopolysaccharide, the therapeutic administration of NAC partially attenuated the extent of ALI through the inhibition of NF-κB activation.
authors.affiliation: Department of Internal Medicine, Clinical Research Institute, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Choi
authors.forename: Ho Sung
authors.initials: HS
authors.lastname: Lee
authors.forename: Ki Hyun
authors.initials: KH
authors.lastname: Seo
authors.forename: Ju Ock
authors.initials: JO
authors.lastname: Na
authors.forename: Yong Hoon
authors.initials: YH
authors.lastname: Kim
authors.forename: Soo Taek
authors.initials: ST
authors.lastname: Uh
authors.forename: Choon Sik
authors.initials: CS
authors.lastname: Park
authors.forename: Mee Hye
authors.initials: MH
authors.lastname: Oh
authors.forename: Sang Han
authors.initials: SH
authors.lastname: Lee
authors.forename: Young Tong
authors.initials: YT
authors.lastname: Kim
keywords: Acetylcysteine; Acute Lung Injury; Antioxidants