The characteristic of acute lung injury in mice exposure to nanometer-sized silica particles

摘要

This paper investigates the characteristic of acute lung injury of mice induced by nanometer-sized silica particles. Forty eight C57BL/6 mice (sex in half) were randomly allocated into test and control group, instilled silica suspension or normal saline into trachea. At 1, 7, 14, and 21 days after treatment, six mice were tested. The nucleated cells in bronchoalveolar lavage fluid (B ALF) were counted, lung histopathology changes were scored, and the ratio of wet to dry weight (W/D) of lung was measured. The results showed that at 1, 7, 14, and 21 days after silica exposure, nucleated cells from BALF and scores of lung histopathology in test group mice were more than that in control group mice (P<0.01), and W/D in test group was more than that in control group mice (P<0.05). Compared with 1 day of mice after silica treatment, nucleated cells in BALF, scores of lung histopathology and W/D for 7 and 14 days of mice all significantly increased (P<0,01). But compared with 7 and 14 days of mice after silica treatment, scores of lung histopathology and W/D for 21 days of mice reduced (P<0.05). In conclusion, after mice exposure to nanometer-sized silica, the acute lung inflammatory strengthens with time during 1-14 days and weakens at 21 days.