Effect of silica on phospholipids in the rat lung
M. Grunspan, H. Antweiler, W. Dehnen
Occupational and Environmental Medicine
Grunspan, M., Antweiler, H., and Dehnen, W. (1973) . British Journal of Industrial Medicine, 30,74-77. Effect of silica on phospholipids in the rat lung. The total amount of phospholipids and the contents of sphingomyelin, phosphatidylcholine, phosphatidylserine, and phosphatidylethanolamine have been estimated in the lungs of rats from 2 to 90 days after intratracheal injections of quartz and corundum, respectively. A significant increase in the contents of lung total phospholipids and of all
... hospholipid fractions examined was caused by quartz. The first increase was noted 48 hours after quartz application; after 30 days the amount of phosphatidylcholine had increased to about 20-fold, whereas the other phospholipid fractions had reached only an amount two or three times as great as in the control animals. The increase observed was steady for up to 90 days at the end of these experiments. The increase in lung phospholipids was far less when corundum was injected into the lungs. The increase in lung lipids after quartz dust inhalation has been studied in rabbits and guinea-pigs by Fallon (1937) , Marks and Marasas (1960) , and Baily, Kilroe-Smith, and Harington (1963) . These investigations referred to the total lipid content of the lung. Changes that might occur in the phospholipid fractions are still unknown. Phosphatidylcholine plays an important role in the composition of the antiatelectatic factor (Pattle, 1965) and phosphatidylserine participates in the phagocytosis mechanism of alveolar macrophages (Karnovsky and Wallach, 1961). Recently we reported changes in the phospholipid content of the lungs of rats after intratracheal injection of quartz (Gruinspan and Antweiler, 1970). In these studies it has been established that quantitative and qualitative changes in lung lipid composition take place during experimental silicosis. In the present study the total amount and the composition of phospholipids in the lungs of normal and quartz-treated rats were analysed at various intervals from 2 to 90 days after quartz application; corundum served for comparison as a non-fibrogenic inert dust. Materials and methods Adult female wistar rats (Firma Iwanowas), weighing 180 to 200 g, were used for these experiments. They were maintained on a commercial standard diet. Three groups of animals were injected intratracheally as follows: (a) 0 5 ml NaCl 0 9 % (controls): 60 rats (b) 20 mg quartz suspended in 0 5 ml NaCI 0 9 Y.: 220 rats (c) 20 mg corundum suspended in 0O5 ml NaCl 0 9 %: 30 rats. The maximum particle size of quartz and corundum (Dorentrup No. 12) was 3 FLm. The specific quartz surface amounted to 9-1 m2/g and that of corundum to 5.34 m2/g. Preparation of dust suspensions Quartz or corundum, 1 g, was mixed with 25 ml 0 9 % 74 on 1 May 2019 by guest. Protected by copyright.