Biliary excretion of cadmium in rat. IV. Mobilization of cadmium from metallothionein by 2,3‐dimercaptopropanol

Abstract

Cadmium was preferentially bound to metaliothionein In tissues 24 h after CdCl ₂ injection. Of a number of chelating agents examined, only 2,3‐dimercapto‐1‐propanol (BAL) was effective in mobilizing Cd from metaliothionein into bile. Structurally similar dithiols such as 1,3‐dimercaptopropanol and 2,3‐dimercapto‐1‐propanesulfonic acid were not effective. Diethylenetriamine pentaacetic acid increased only the urinary excretion of Cd. Biliary excretion of Cd increased with increasing dose of BAL, and there was a concurrent decrease in hepatic Cd levels without any increase in renal concentration. BAL was effective even 14 d after Cd injection. The form of Cd excreted in the bile after BAL injection in chronic exposure has not yet been characterized. Initial studies suggested that it was not metaliothionein but was a low‐molecular‐weight Cd complex, probably with BAL.