Effects of cadmium on calcium metablisms of ovariectomized rats

  Objective   To investigate effects of cadmium on calcium metabolisms of ovariectomized rats.

  Methods   Female Sprague-Dawley rats aged 6 months were ovariectomized.The rats were administrated with cadmium at the dose of 0, 50, 100 and 200 mg/L in drinking water for 24 weeks.Urine and feces of 24 hours were collected after 6, 12, 18 and 24 weeks, respectively.Cadmium concentration in urine, blood and bone were measured by an atomic absorption spectrophotometer.And urinary β₂-MG and serum estradiol were detected by RIA.The calcium contents in bone, urine and feces were assayed.

  Results   Compared to the sham operation group, estradiol significantly declined in the ovariectomized rats.After cadmium administration, the excretions of calcium in feces and urine increased significantly in a dose-response related pattern.And calcium contents of bone were significantly lower in the group exposed to 200 mg/L cadmium in drinking water than in the control group.Urinary β₂-MG was significantly higher in cadmium-exposed groups.Meanwhile urinary β₂-MG positively related to total excretions of calcium in 24 hours.

  Conclusion   The results indicated that cadmium could inhibit calcium metabolisms by increasing the excretions of calcium in feces and urine, which probably resulted in significant calcium declines in bone.