Abstract: Objective: To explore the influence of pulmonary fibrosis induced by chronic ethanol ingestion in rats with N-Acetylcysteine(NAC), through observe the chang of pathogenesis of pulmonary fibrosis with detecting the content of SOD, MDA of lung tissue. Methods: 30 Clean healthy male Sprague-Dawley rats, were randomly divided into alcohol group(10), alcohol+NAC group(10), and control group(10). Feeding quantitative non-ethanol or ethanol Lieber-Decarli liquid diet every day for 8 weeks. Alcohol+NAC group were given NAC 300mg/(kg?d). At study completion, animals were sacrificed, The pathogenesis changes of lung tissue were observed; The activity of SOD and content of MDA of lung tissue were detected. Results: there were varying degree of alveolar and alveolar septal infiltration of inflammatory cells, and there were more deposition of collagen fibers at intervals of alveolar in ethanol group. The similar presents were in ethanol +NAC group, the degree was lower than alcohol group. The degree of alveolitis and the degree of pulmonary fibrosis in alcohol+NAC group were lower than it in alcohol group, (P＜0.01; P＜0.05, respectively). 2. the SOD activity of lung tissue in alcohol+NAC group was higher than alcohol group, the MDA content of lung tissue in alcohol+NAC group was lower than alcohol group (P＜0.05).Conclusion: NAC can raise the SOD activity and decrease the content of MDA of lung tissue in chronic ethanol ingestion rats, restrain the oxidative stress induced by alcohol, decrease the degree of pulmonary fibrosis induced by chronic ethanol ingestion in rats .

Key words: ethanol, pulmonary fibrosis, N-Acetylcysteine, Malondialdehyde, Superoxide dismutase