镉对去卵巢大鼠骨密度和肾功能的影响

The effect of cadmium on the bone mineral density in the ovariectomized rats

目的 研究镉对去卵巢大鼠骨密度的影响及其与肾脏损伤的关系。方法 将SD大鼠行人工去卵巢术 ,分别经饮水给不同剂量的镉染毒 ,2 4周后处死。用双能量X线骨密度仪 (HOLOGIC ,QDR 40 0 0 )测定股骨颈、股骨中点及腰椎的骨密度 ,用石墨炉原子吸收法测定血、尿及骨镉 ,放免法测定血清雌二醇 ,同时测定镉肾损伤指标尿 β2 微球蛋白和尿钙。结果 大鼠去卵巢后 ,体内雌二醇水平低下 ,骨密度明显下降。镉染毒可使大鼠股骨颈的骨密度明显降低 ,且随镉染毒剂量增加呈下降趋势。镉染毒后 ,大鼠发生肾损伤 ,尿 β2 微球蛋白和尿钙含量升高。同时股骨颈的骨密度与肾损伤指标 β2 微球蛋白有显著性相关。结论 镉染毒可降低去卵巢大鼠的骨密度 ,对股骨颈作用尤为敏感 ,而且镉引起的骨损伤与镉造成的肾损伤相关。

Objective To investigate the effect of cadmium on the bone nineral density in the ovariectomized rats and its relationship with renal damage caused by cadmium.Methods Female Sprague Dawley rats at the age of 6 months were ovariectomized. The rats were administrated with the cadmium at the doses of 0,50,100,200 mg/L in drinking water. After 24 weeks, the rats were killed and measured the bone mineral density (BMD) at the femur, necks, middle point and lumbers by dual energy X ray absorptiometry (HOLOGIC, QDR 4000). The cadmium concentrations in urine, blood and bone were measured by an atomic absorption spectrophotometer (AA 800, Perkinelmer Co, USA), and the estradiol contents in serum were assayed by the radionimmuoarry kit (DSL CO., USA). The indicators of renal damage caused by cadmium, (ie. urinary calcium and β 2 MG), were also detected.Results Compared to the control group, the ovariectomized rats had lower BMD and estradiol in serum. Cadmium had significant effects on bone by reducing BMD at the necks of femurs. The concentrations of calcium and β 2 MG in urine were significantly higher after administration of cadmium. And there were significant relationships between the BMD of femur necks and the cadmum level in rats and the urinary β 2 MG. Conclusion Cadmium could decrease the BMD in the ovariectomized rats, especially at the femur necks, and the bone damage induced by cadmium was related to renal damage caused by cadmium.