Research On The Protection Of Heme Oxygenase-1 In The Lung Fibrosis Of Rat Induced By Gejiu Tin Dust

[ Objective ]To investigate the protection of heme oxygenase-1 in the lung fibrosisof rat induced by Gejiu tin dust. [Methods ] 64 adult Spragne-Dawley rats weredivided into 4 groups: the rat in contol group(n=8) which did not receive any treat;therat in phosphate-buffer-solution(PBS) group(n=8) which were treated with a singleinstillation of 0．01M PBS(0．1ml/100g), the rats were killed by exsanguinations ondays 14; the rats in dust group(n=24) which were treated with a single instillation of5% dust suspension(0．1ml/100g); the rats in inhibitor group(n=24) which weretreated with a single instillation of 10umol/kg ZnPPⅨby intraperitoneal injection on1h before injecting dust suspension per 48h, three in all. On days 14, 28 and 56, theanimals were killed by exsanguination respectly. The expression of heme oxygenase-1in the rat lungs were measured by immunohistochemistry. The lung samples wereprocessed for light microscopy by HE and Masson staining. The hydroxyproline(HYP)concentration was determined by the method of sample alkali hydrolization.The myeloperoxidase(MPO) concentration was determined. The MaleicDialdehyde(MDA) concentration was determined by the method of DAB. Thestatistical analysis was carried out using SPSS 11．5 for Windows. Data werestatistically analyzed using a one-way analysis of variance followed by the Dunnett'smultiple comparison test. Wilcoxon test was used to ranked data. P < 0．05 wasconsidered statistically significant. [ResuIts] Histopathological evaluation: Typicalpathological inflammation changes in the lung of rats treated with dust on days 14were observed, there was a little fibroelastosis in the lung of rats treated with dust ondays 28, significant fibroelastosis changes in the lung of rats treated with dust on days56．Compared with control group and PBS group , content of HYP was increased in the lung of rats treated with dust on days 14, but there was no statistical significientdifference(P > 0．05) . Content of HYP markedly was increased on days 28 and 56 ofdust group, there was statistical significient difference (P < 0．01) . Compared withcontrol group and PBS group, MPO activity and content of MDA was increasedmarkedly in the lung of rats treated with dust on days 14 (P<0．01, P<0．01) , MPOactivity and content of MDA which were decreased in the lung of rats treated withdust on days 28 and on days 56 was higher than the lung of rat in normal group andPBS (P<0．01, P<0．01) . ZnPPⅨinhibitor, a specific inhibitor of heme oxygenase-1,inhibited the expression of HO-1 in rat lung tissue. Injury of inflammation andoxidative stress in rat lung tissue was aggravated, the lung f?brosis of rats treated byZnPPIX inhibitor was heavier than the rat treated with dust (P<0．01) . [Conclusions]The rat instillated in tratracheal with 5% tin dust suspension (0．1ml/100g) can besuccessful animal model of pulmonary fibrosis on 56 days. Heme oxygenase-1 play aprotective role in the rat lung fibrosis induced by Gejiu tin dust.