Changes in pulmonary surfactant and phosphatidylcholine metabolism in rats exposed to chrysotile asbestos dust

Abstract

Pulmonary surfactant was isolated from rats exposed to chrysotile asbestos dust for 3 days-15 wk. Asbestos treated rats showed a progressive increase in amounts of surfactant. After 15 wk, treated animals contained 4 times as much as non-treated. No significant change was seen in the total protein or total fatty acid composition of surfactant with exposure. Increase in surfactant phosphatidylcholine normally seen on maturation of rat lung was accelerated by exposure of animals to asbestos. An increase in activity of phosphorylcholine glyceride transferase in lung homogenates and free cell populations was found. Lysosomal phospholipase A was relatively unaffected by dust exposure. The increase in surfactant amounts probably could be due to an increase in its synthesis without corresponding alteration in its degradation.