Effect Of N-acetylcysteine On The Expression Connective Tissue Growth Factor In Pulmonary Fibrosis Rats

Objective: To evaluate effect of N-acetylcysteinein on pulmonary interstitial fibrosis, we investigated pathological change of lung and genetic and protein expression of CTGF in bleomycin-induced pulmonary interstitial fibrosis in rats which were treated with N-acetylcysteinein. To provide a foundament for using N-acetylcysteine in clinic avidence to using in order to NAC in patients with interstitial lung disease. Methods: Thirty female Wistar rats were randomly divided into three groups: a bleomycin-induced-fibrosis group(Group B) which was administered to bleomycin (5mg/kg) intratracheally, a bleomycin-induced-fibrosis group treated with N-acetylcysteine (3mmol/kg. day) (Group N) and the control group (Group C) which was treated with saline. Group N were fed with N-acetylcysteine every day from one week before the single intratracheal instillation of blemycin upto the day being executed on the 7th and 14th day. We observed their pulmonary pathological change under HE staining and the change of mRNA and protein expression of CTGF by immunnohistochemical method in the right lung. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of CTGFmRNA in the left lung. Results: The most serious pulmonary fibrosis was found in Group B while Group C shows no obvious alveolitis and lung fibrosis. Attenuation of alveolitis and lung fibrosis after treatment with NAC was observed in pathological section (P<0.05). Expression of CTGF protein and CTGFmRNA in group B were higher than group C at 7th and 14th day (P<0.05). Compared with group B, the level of expression of CTGF protein and CTGFmRNA in group N decreased at 7th and 14th day after treatment with NAC.Conclusion: N-acetylcysteine can inhibit alveolitis and fibrosis. It maybe plays a protective role by inhibition of the production of CTGF protein and CTGFmRNA. N-acetylcysteine has notable protective effects in bleomycin-induced pulmonary interstitial fibrosis of rats.