[Autophagy in lung tissue of rats exposed to silica dust].

Objective: To investigate the autophagy of effector cells in lung tissue at different time points when rats were exposed to free SiO2 dust.

Methods: Sixty Wistar rats (220∼230 g) were selected and allocated to experimental group (n = 30) and control group (n = 30). In the experimental group, a rat silicosis model was established by infusing SiO2 suspension into the trachea of rats.

[Macrophage apoptosis and the levels of interleukin-1 and interleukin-8 in the rats exposed to silica].

Objective: To study the roles of macrophage apoptosis, IL-1, and IL-8 in the pathogenesis of rat pulmonary fibrosis induced by silica.

Methods: Forty eight male Wistar rats were divided into the 4 control groups (24 rats) and 4 experimental groups (24 rats). Rats in the control groups were treated with 1 ml normal saline by trachea instillation, whereas the rats in experimental groups were exposed 1 ml silica suspension (100 mg/ml) by trachea instillation for 1, 7, 14 and 28 days, respectively.