Effect of short-term exogenous pulmonary surfactant treatment on acute lung damage associated with the intratracheal instillation of silica.
J Toxicol Environ Health 1994 Sep; 43(1):85-101
The use of Survanta protection against silica (14808607) cytotoxicity in alveolar macrophages (AMs) was assessed in cells exposed to Survanta coated silica versus untreated silica. The ability of Survanta to delay lung damage was also examined following instillation of the surfactant and silica in male Fischer-344-rats. The in-vitro trials showed that only 14% of the AM cells survived silica treatment without Survanta 1 hour postexposure. Survanta treatment maintained approximately 85% cell survival 1 hour after silica exposure and 65% of these cells were still viable 24 hours after treatment. To determine if instillation of Survanta would minimize or delay silica damage in rats, biochemical and cellular markers of lung injury were measured, including protein levels, beta- glucuronidase activity, total cells, and the number of neutrophils in bronchoalveolar lavage fluid (BALF) 1 and 14 days after instillation with silica and Survanta. Compared to uncoated silica treatment groups, rats receiving silica coated with Survanta presented significantly reduced levels of protein and beta- glucuronidase activity; however, this protection was temporary as no protective effect was observed at 14 days. Survanta treatment was also observed to completely inhibit the migration of neutrophils into alveolar spaces 1 day after treatment compared to the group exposed to untreated silica. This protective effect disappeared by day 14 with respect to total cell counts while neutrophil counts remained low. According to the authors, strong consistency between the in-vivo observations and in-vitro effects demonstrates the potential of Survanta to attenuate chronic toxicity to silica dust, at least on a short term basis.
NIOSH-Publication; NIOSH-Cooperative-Agreement; Surfactants; Silica-dusts; Respiratory-protection; Alveolar-cells; Laboratory-animals; Cytotoxic-effects
Journal of Toxicology and Environmental Health
Center to Protect Workers' Rights