Cadmium-induced immunopathology is prevented by zinc administration in mice.
Six-week-old C57BL/6 male mice were exposed to 50 mg cadmium/L drinking water (50 ppm) for 3 wk, and killed at 0, 3 and 6 wk after cessation of treatment. In some groups, 500 mg zinc/L was added to the drinking water (500 ppm) with or after cadmium treatment. The number of direct and indirect splenic plaque-forming cells was higher in cadmium-treated mice at 0 wk than in untreated controls. Concurrent zinc administration prevented the enhancement of plaque-forming cell response. Proliferative response of spleen cell culture to the T-cell mitogens phytohemagglutinin and concanavalin A was slightly high in cadmium-treated mice at 0 wk and zinc administered after exposure to cadmium tended to lower it. The number of Lyt-2 positive cells in the spleen was lower and the ratio of L3T4 to Lyt-2 positive cells, reflecting the balance of immunoregulatory T-lymphocytes, was higher after cadmium treatment than in untreated controls. Concurrent zinc administration prevented the alteration of T-cell subsets. Cadmium and zinc treatment had no effect on liver, kidney, spleen and thymus weights and lymphocyte content of spleen, thymus and peripheral blood. Use of immunofluorescence with anti-mouse IgG and C3 showed no evidence of an autoimmune reaction in kidney sections. Liver and kidney cadmium concentrations were high at all observation times in the cadmium-treated animals. Tissue cadmium levels were lower in mice treated with both zinc and cadmium than in those treated with cadmium alone.(ABSTRACT TRUNCATED AT 250 WORDS)
Chowdhury
B A
BA
Department of Pediatrics and Biochemistry, Memorial University of Newfoundland, St. John's, Canada.
Friel
J K
JK
Chandra
R K
RK
D000818:Animals; D001327:Autoimmune Diseases / Q000517:prevention & control; D002104:Cadmium / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000633:toxicity*; D007107:Immune System / Q000187:drug effects*; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D007668:Kidney / Q000276:immunology; D007958:Leukocyte Count / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009929:Organ Size / Q000187:drug effects; D013154:Spleen / Q000187:drug effects; D010948:Viral Plaque Assay; D015032:Zinc / Q000494:pharmacology*
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D002104:Cadmium; D015032:Zinc