Cadmium-induced immunotoxicity

This study assessed the effects of cadmium on functional lymphopoietic precursor cells and cell size in both spleen and bone marrow. Splenic plaque-forming cell (S-PFC) precursors were stimulated by a thymus independent immunogen (TNP-LPS) and by a thymus dependent immunogen (TNP-BSA plus dextran sulfate). Bone marrow plaque-forming cell (M-PFC) precursors were stimulated by TNP-LPS plus dextran sulfate. Male C57Bl/6J mice received either a single ip injection of 5.9 mg/kg CdCl2, and were sacrificed 3 days later (ip group), or 5 daily sc injections of 3.26 mg/kg CdCl2, and were sacrificed either 2 days later (7 day sc group) or 7 days later (12 day sc group). The ip group showed an increase in spleen cellularity which resulted in an enhanced S-PFC (TNP-LPS) response per spleen and compensated for a depressed S-PFC (TNP-BSA) response per 10(6) cells cultured. Bone marrow cellularity was not significantly decreased but the M-PFC response was drastically depressed. Similar results were obtained in the 7 day sc group. However, a significant increase in spleen cellularity was not seen, resulting in a noncompensated decrease in S-PFC (TNP-BSA) response. The S-PFC (TNP-LPS) response per 10(6) cells cultured was increased in this group. Responses were similar to controls in the 12 day sc group, but bone marrow cellularity was decreased. The ip and 7 day sc groups showed substantial cadmium-induced shifts in bone marrow cell size distribution profile to larger diameters. Changes in spleen cell size distribution were not as significant. Partial recovery was evident in the 12 day sc group. This study demonstrated that in vivo exposure to cadmium has a greater effect on the in vitro function of immature B-cells in the bone marrow than on more mature B-cells found in the spleen.(ABSTRACT TRUNCATED AT 250 WORDS)