Abstract:Objective To study the protective effect of Amlodipine on pulmonary fibrosis in rats and the possible molecular mechanism, so as to find new ways for the treatment of pulmonary fibrosis. Methods Totally 240 rats were divided into control group, model group, Pirfenidone group and Amlodipine group at random. The rats in the model group, Pirfenidone group and Amlodipine group were perfused with Bleomycin through trachea to build the model of pulmonary fibrosis, those in the control group were perfused with saline. Then the rats in the control and model groups were given normal saline, but the rats of the Amlodipine group and the Pirfenidone group were treated with half volume of Amlodipine and Pirfenidone respectively together with half amount of normal saline. Single factor analysis and U test were used to analyze the pulmonary fibrosis score and alveolitis score at 1 , 2 and 4 weeks in the 4 groups, and also the content of thrombospondin 1 (TSP-1), TGF-β1 and mRNA of type I collagen and type III collagen was analyzed. Results The four indexes in the Amlodipine group and the Pirfenidone group were significantly lower than those in the model group at each time point (P < 0.05), they were obviously lower in the Amlodipine group than in the Pirfenidone group (P < 0.05). The alveolitis and pulmonary fibrosis scores in the Amlodipine and Pirfenidone groups were significantly lower than those in the model group (P < 0.05), and they were obviously lower in the Amlodipine group than in the Pirfenidone group (P < 0.05). Conclusions Amlodipine can significantly reduce lung alveolitis and pulmonary fibrosis, possibly through inhibition of TGF-β1 and TSP-1 and reduction of type I and III collagen mRNA expression.