Gastrointestinal absorption and organ distribution of oral cadmium chloride and cadmium‐metallothionein in mice.

Body retention and tissue distribution of Cd from oral 109 CdCl 2 and 109 Cd‐metallothionein were studied in C57BL/6J mice given identical doses (60 μg Cd and 2 μCi 109 Cd). Measurement of 109 Cd radioactivity in mice showed identical absorption but differences in tissue distribution of Cd from the two forms. A significantly greater deposition of Cd was observed in the kidney of mice fed Cd‐metallothionein than in the CdCl 2 group where a major portion of Cd was deposited in the liver. Most of the radioactive Cd in the renal and hepatic tissues and in the duodenum was bound to metaltothionein 24 h after oral Cd‐metallothionein, whereas only 30 and 38% of the cadmium in liver and kidney supernatants, respectively, were bound to metallothionein after oral CdCI 2 . These results suggest that the dietary form of Cd may influence the renal deposition of Cd. [ABSTRACT FROM PUBLISHER]