[Protective effect of N-acetylcysteine on acute lung injury caused by exposure to rocket liquid propellant].
OBJECTIVE
To investigate the protective effect and its mechanisms of N-acetylcysteine (NAC) on acute lung injury (ALI) caused by exposure to high concentration rocket liquid propellants asymmetrical dimethylhydrazine (UDMH) and dinitrogen tetroxide (N(2)O(4)).


METHODS
Forty-two rats were randomly divided into three groups: the control group, the exposure group and the exposure plus the treatment group (NAC group). The rats of the latter two groups were exposed to UDMH 0.98 mg/L for 10 minutes and then N(2)O(4) 0.19 mg/L for another 10 minutes. After the exposure, the NAC group rats received immediately 150 mg/kg of NAC intravenously, and rein forced by intraperitoneal injection of NAC with a dose of 50 mg/kg 3 hours after the intravenous injection. The rats of other group were treated with saline in equal volume. All rats were killed after 6 hours. The lung wet to dry ratio (W/D ), the contents of lactate dehydrogenase (LDH) and total protein in bronchoalveolar lavage fluid (BALF), the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in lung tissue, and the malondialdehyde (MDA) of plasma were measured. Pathological examination was performed.


RESULTS
The lung W/D ratio, the LDH and total protein in BALF, and the MDA of plasma were increased in the exposure group, while the activities of SOD and GSH-Px in lung tissue were decreased. The histopathology of the rats of exposure groups showed that there was exudation within alveolar spaces and prominent interstitial thickening of septa. In the NAC group, the values of the above findings were lowered, and the degree of lung injury was alleviated in histopathology. The lung W/D were negatively correlated with the activities of SOD and GSH-Px in lung tissue, and the correlation coefficient were-0662 (P<0.01) and -0707(P<0.01) respectively.


CONCLUSIONS
The administration of NAC appears to attenuate the injury to the lung after an exposure to UDMH and N(2)O(4) in high concentration, and the antioxidant activity of NAC may be responsible for the protective effect.
Department of Respiratory Disease, General Hospital of PLA, Beijing 100853, China. liusongyy@yahoo.com.cn
Song
S
Liu
Sen-Yang
SY
Yu
D000111:Acetylcysteine / Q000627:therapeutic use*; D055371:Acute Lung Injury / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D004127:Dimethylhydrazines / Q000633:toxicity*; D004195:Disease Models, Animal; D005979:Glutathione Peroxidase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D008168:Lung / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009589:Nitrogen Oxides / Q000633:toxicity*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000378:metabolism
D004127:Dimethylhydrazines; D009589:Nitrogen Oxides; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; C015167:nitrogen tetroxide; D000111:Acetylcysteine