Recovery of the murine mononuclear phagocytic system following chronic exposure to cadmium.

Consistent with our previously reported findings, chronic ingestion of cadmium chloride in drinking water by mice caused a decrease in the rate of circulation clearance of 51Cr-labeled sheep red blood cells (E) and IgG-coated E (E-IgG) due to a decrease in the localization of E and E-IgG in the liver. These decreases reached their nadirs after 15 weeks of cadmium ingestion and remained relatively constant for up to one year during continued ingestion of cadmium. Replacement of the drinking water containing cadmium with regular tap water resulted within 8 days in an improvement in the ability of the mice to clear E and E-IgG. Mice also had a decreased ability to develop delayed-type hypersensitivity reactions while being given cadmium; this abnormality also returned toward normal after withdrawal of cadmium. The return of these two responses toward control levels occurred while there was still a large organ burden of cadmium that was not measurably different from that at cessation of cadmium ingestion.