Experimental study on the effect of Si and P ion content in SiO2 exposure environment on the degree of pulmonary fibrosis.

Silicosis is a public health issue in developing countries for long and cannot be completely cured.To study the changes of ion content with TNF-α and TGF-β expression in alveolar lavage fluid (BALF) at different time points in rats exposed to silica and to investigate their correlation with pulmonary fibrosis.42 rats were randomly divided into control group (n = 12) and exposure group (n = 30). Tissues of right lower lungs were collected and fixed for further Hematoxylin-eosin (HE) and Masson staining. We collected the BALF to examine the inflammatory cytokines of TNF-α and TGF-β and measured the ion contents in BALF.The increase of TNF-α level was earlier than TGF-β. The content of silica in BALF was significantly increased after exposure and reached the maximum at 7th day, similar to the curve of cytokine TGF-β level. However, phosphorus ions increased quickly after gradual decline of silicon ion and roughly proportional to the curve of degree of fibrosis.Crystalline silica exposure can cause changes in TGF-β and TNF-α in BALF and accompanied with fibrosis and ions content variation. The abnormal expression of phosphorus ion may have significance in the occurrence and development of silicosis.