Expression of relaxin family peptide receptor 1 in the lung tissue of silicosis rats / 中国职业医学

ABSTRACT

OBJECTIVE: To investigate the potential effect of relaxin family peptide receptor 1( RXFP1) in the process of silica-induced silicosis. METHODS: Sixty-four specific pathogen free male Wistar rats were randomly divided into control group and experimental group. By one time intratracheal infusion,rats in experimental group were treated with 0. 1 m L 500 g / L silica dust suspension while the control group was treated with 0. 1 m L sodium chloride physiological solution. Eight rats from each group were sacrificed on day 1,7,14 and 28 after exposure. Histopathologic changes of the lung tissue were performed with hematoxylin-eosin staining. The expressions of Rxfp1 mRNA and RXFP1 protein in rat lungs were detected by real-time polymerase chain reaction and immunohistochemical staining,respectively. RESULTS: After 28 days of exposure,the grey nodules were observed by naked eye in the lung of the experimental group. The fracture and silicotic nodules could be seen in alveolar interval with light microscope. Compared with the control group,the Rxfp1 mRNA relative expression level in the lungs of experimental group was increased to 145% after 1 day of exposure( P < 0. 01),followed by a decrease on day 7 and 14 and reached similar level of control group( P > 0. 05). By day 28,it dropped to45% of control group( P < 0. 01). The RXFP1 protein relative expression in experimental group was significantly up-regulated since the 7th day compared to that of the control group( P < 0. 01). And it reached to the highest level on the28 th day( P < 0. 01). CONCLUSION: The RXFP1 might play an important role in inhibiting silicosis.