Related Experiment Video
Updated: Jan 21, 2026

Establishing a Silicosis Rat Model via Exposure of Whole-Body to Respirable Silica
Published on: October 28, 2022
Dynamic Variation of RAS on Silicotic Fibrosis Pathogenesis in Rats
Bo-Nan Zhang1,2,3, Xin Zhang2, Hong Xu2
1School of Public Health, North China University of Science and Technology, Tangshan, 063210, China.
Abstract:
The dynamic variation of renin-angiotensin system (RAS) in silicosis remains unclear. Seventy Wistar rats were divided into 7 groups including control group, silicosis groups (inhaling SiO2 for 2, 4, 8, 16 and 24 weeks, respectively) and Captopril (Cap) group. Rat lung primary fibroblasts were divided into control group, SiO2-stimulated group (0, 0.5, 1, 3, 6, 12, 24 and 48 h) and Cap group. The silicotic nodules were formed and collagens were deposited gradually in silicosis group observed by haematoxylin and eosin (HE) staining and Van Gieson (VG) staining. Cap relieved the lung fibrosis and collagen deposition. Immunohistochemistry indicated the positive expression of α-smooth muscle actin (α-SMA) was increased gradually in silicotic rat lung tissue. Western blotting revealed the expression of collagen type I (Col I) and α-SMA was up-regulated in silicotic rat lung tissue and fibroblasts stimulated by SiO2. Cap decreased the expression of Col I and α-SMA in silicotic rat lung tissue and fibroblasts stimulated by SiO2. Western blotting also demonstrated the expression of angiotensin-converting enzyme (ACE) and angiotensin II type 1 receptor (AT1) was increased, and the expression of ACE2 and Mas was decreased gradually in silicotic rat lung tissue and fibroblasts stimulated by SiO2. ELISA showed the serum levels of ACE and angiotensin II (Ang II) were also increased and ACE2 and Ang (1-7) were decreased in the silicosis group. Treatment with Cap decreased the expression levels of ACE, Ang II and AT1, and increased the expression levels of ACE2, Ang (1-7) and Mas. These findings suggested that an imbalance between ACE-Ang II-AT1 axis and ACE2-Ang (1-7)-Mas axis may participate in the development of silicosis.
Related Concept Videos
Cystic Fibrosis: Pathogenesis
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation,...
The Ras Gene
Ras is a...
What is Variation?
The range, standard deviation, standard error, and variance are the different measures of variation.
Range: The range is the difference between its maximum and...
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
Variation
When independent and dependent variables are plotted on a scatter plot, the slope of a line is a value that describes the rate of change between the two...
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...

