The Injurious Effect of Quartz on Cell Membranes and the Preventive Effect of Aluminium Citrate against Quartz.
Cao-CJ; Liu-SJ; Lin-KC
NIOSH 1990 Nov:947-953
The effect of quartz (14808607) dust on cellular membranes and the protective effect of aluminum-citrate were studied in-vitro. Cultures of guinea-pig alveolar macrophages and rabbit erythrocytes were incubated with 0 to 1000 micrograms (microg) quartz dust for up to 60 minutes. In some experiments the cultures were pretreated with 31.3 to 1000microg aluminum as aluminum-citrate. The effects on membrane lipid fluidity, permeability to potassium ion (K+), sodium/potassium ion dependent ATPase (Na,K-ATPase), water content, and electric charge were determined. Quartz caused significant dose and time dependent increases in membrane lipid fluidity of the macrophages. Aluminum-citrate protected against this effect; the effect was dose dependent. Quartz increased macrophage membrane permeability to K+. The increase in K+ permeability was significantly correlated with the increase in lipid fluidity. Aluminum-citrate prevented the effect of quartz on K+ permeability. Na,K-ATPase activity was not significantly affected by quartz. Quartz caused significant dose dependent decreases in membrane water content of erythrocytes leading to dehydration of the membrane. Aluminum-citrate protected against this effect. Quartz increased the electrophoretic mobility of macrophages by increasing the negative electrokinetic potential and membrane charge density. Aluminum-citrate alone decreased electrophoretic mobility and at doses of 125 to 500microg abolished the effect of quartz. The authors suggest that the toxic effects of quartz on cellular membranes are due to its increasing membrane fluidity and permeability and interacting with positively charged moieties in membrane phospholipids. The protective effect of aluminum-citrate is due to its ability to inhibit these processes.
In-vitro-studies; Alveolar-cells; Silica-dusts; Mineral-dusts; Membrane-dysfunction; Prophylaxis; Aluminum-compounds; Plasma-membrane; Bioelectric-effects; Dose-response; Red-blood-cells;
Proceedings of the VIIth International Pneumoconioses Conference