The distribution and binding of cadmium in oyster, soybean, and rat liver and kidney

Exposure to Cd and/or 109Cd has shown that the element was efficiently accumulated in oysters and soybeans as well as in rats. Differential centrifugation of oyster, soybean, rat liver, and rat kidney homogenates followed by analysis showed that Cd was associated primarily with proteins in the 105,000 X g supernatants. Separation of these proteins by Sephadex chromatography and subsequent analysis by atomic absorption spectroscopy or by radioactivity measurements revealed that Cd in oysters and rat organs was principally bound to proteins of 9,200 to 13,800 molecular weight. A significant amount of Cd in oysters was also associated with fractions of greater than 50,000 and less than 3,000 molecular weights. Almost all of the Cd in soybeans was found to be bound to molecules of greater than 50,000 molecular weight.