A Study on Change of Type I and III Collagen during Fibrosis Induced by Silica and Welding Fume Dust.
NIOSH 1990 Sep:566-570
An investigation was conducted by applying the enzyme linked immunosorbent assay method to the determination of the contents and distribution of Type-I and Type-III collagen in female Wistar-rats who had been exposed to either quartz (14808607) dust or welding fume dust. The contents of Type-I and Type-III collagen in silicotic rat lung were both increased continuously as the time increased after dusting. At 10 days after dusting the ratio was about two and remained at a constant level until 90 days after dusting. Histological study of collagen fibers in the slices indicated that the alveolar septa and lung interstitial were all expanded and had accumulated Type-I and Type-III collagen. Type-III collagen predominated at 10 days after dusting with silica while at 20 days Type-I collagen was the primary one present. In the rats exposed to welding fume dust, the content of Type-III collagen was significantly greater at 30 days post exposure but there was no significant increase of Type-I collagen until about 180 days after dusting. The ratios of Type-I/Type-III collagen in the lung decreased gradually within 90 days and were raised to nearly normal levels at 180 days. The authors conclude that the type of welding fume dust used induces a slower and milder lung fibrosis when compared to silicosis.
Mineral-dusts; Airborne-dusts; Fibrous-bodies; Cell-damage; Dust-exposure; Silica-dusts; Lung-cells; Cell-function; Laboratory-animals; Welders;
DHHS (NIOSH) Publication No. 90-108
Proceedings of the VIIth International Pneumoconioses Conference