| Abstract: | Silica dissolving out from the slate dust was found to bind with plasma protein and purified bovine serum albumin. At 24 h of incubation at 37 degrees C binding affinity of silica (microgram of silica bound/mg of protein) with plasma protein and bovine serum albumin was found to be 0.59 and 0.44, respectively. By molecular exclusion chromatography using Sephadex G-200, silica binding protein of plasma was determined to be of mol. wt. around 67000. Similar proteins having silica binding capacity (mol. wt. 70000 and 85000) were also found in rat lung but these proteins unlike their plasma counterpart were glycoprotein in nature. Polyacrylamide gel electrophoresis of plasma and protein rich lung fraction show that proteins upon binding with silica undergo mobility changes. Significance of the existence of silica binding protein in plasma and lung of rat in relation to silica toxicity is discussed. |
