EFFECT OF CADMIUM IN THE ZINC-DEFICIENT RAT

Three-w-old male Sprague-Dawley rats were given a zinc (Zn)-deficient (0 ppm Zn) or a Zn-adequate diet (30 ppm Zn) supplemented with 0, 0.5 or 100 ppm cadmium (Cd) for up to 5 mo. The proximal convoluted tubule s of the kidneys had degenerative changes in the rats fed the Zn-defic ient diet containing 100 ppm Cd [Zn 0, Cd 100], but there were no lesi ons in other groups. Electron microscopy showed cytoplasmic vacuolatio n of the proximal tubules, mitochondrial swelling and coagulative necr osis in Zn O:Cd 100 rats. The present study revealed diminished bone g rowth and cortical thinning of the femur, but there was no osteomalaci a seen In ltai-ltai disease patients. The results indicate that Zn def iciency may enhance the renal toxicity of Cd, but that dietary Cd did not cause osteomalacia even under severe Zn-deficient conditions.