Cadmium absorption in mice: Effects of broiling on bioavailability of cadmium in foods of animal origin

The absorption and organ distribution of organic Cd from raw and broiled ho rse kidney was compared to that of CdCl2 at two dose levels (0.05 and 3 mg Cd/kg feed) in a feeding study in mice. The high Cd concentration in the ho rse kidney (raw 112 mg/kg; broiled 53 mg/kg) made it possible to mix kidney into mouse feed without marked effects on the composition of the feed. The weight of the mice, feed and water consumption, and Cd levels in the feed were determined once a week. After 9 wk of exposure, the liver and kidneys of the mice were sampled and Cd was analyzed. The Cd concentration in horse kidney was halved by broiling, and the content of soluble Cd decreased fro m 12% in raw kidney to 5% in broiled kidney. The majority of the soluble Cd was associated with proteins with the same molecular weight as metallothio nein ( MT) in both raw and broiled kidney. Broiling of the kidney had no ma rked effect on the fractional accumulation of organic Cd in mice. The fract ional accumulation of inorganic CdCl2, on the other hand, was significantly higher than that of organic Cd in the low dose groups but not in the high dose groups. The ratio between Cd accumulation in kidney and that in liver was higher in the group receiving raw kidney compared to the ratio in the g roup receiving CdCl2 at both the high and low exposure levels. This indicat es that the raw kidney contained a Cd form that was more preferentially dis tributed to the kidneys.