Binding of cadmium and mercury by metallothionein in the kidneys and liver of rats following repeated administration

Rats were injected subcutaneously with either cadmium chloride (0.5 mg Cd/kg) or mercuric chloride (0.5 and 0.25 mg Hg/kg) every other day over a period of 6 to 7 weeks. Levels of metals and metallothionein were determined in liver and kidneys. Both cadmium and metallothionein accumulated in these organs during the period of exposure. Mercury and metallothionein accumulated only in the kidneys. Mercury did not accumulate in the liver, nor did it cause an increase of metallothionein in the liver. The molar ratio of 1.6 (metal to metallothionein) in liver was constant for cadmium. In the kidneys this ratio varied from 1 to 3 for both metals, depending on the level of the metal; This ratio was 0.1 for liver mercury.This work was partly supported by the Polish-American agreement No. 05-009-2 with National Institute for Occupational Safety and Health, PHS, USA.