铅暴露对机体钙、锌水平的影响

Effects of Lead-Exposed on the Levels of Calcium and Zinc in vivo and in vitro

目的探讨环境铅暴露对机体钙、锌水平的影响。方法(1)大鼠自由饮用醋酸铅(400 mg/L Pb2+计),建立铅暴露动物模型,连续染毒4周,原子荧光光度法测定眼球血、肝脏、骨骼、尿液、粪便中铅、钙、锌水平。(2)采用人红细胞培养及红细胞加铅培养2 h(每毫升血加铅5μg),原子荧光光度计测定染铅前后细胞铅、钙、锌水平。结果铅暴露4周后,体内器官铅浓度为肝脏>血液>骨骼;骨骼铅浓度上升最快,与对照组比较,增加倍数7倍以上。尿中钙、锌排出增加,肝中钙、锌水平下降。人红细胞染铅后,细胞内钙、锌水平显著降低。结论大鼠铅暴露可导致铅在骨骼和肝脏的蓄积,并引起机体钙、锌的丢失,降低机体钙、锌水平。

Objective To discuss the effects of lead-exposed on the levels of calcium and zinc in some organs of rat. Methods In vivo test： the model of lead-exposed experimental animal was estabished, lead acetate liquor（with 400 mg/L Pb^2＋ ） for the rats to drink freely. After having been continuously contaminated for four weeks, the blood of eyeball, liver, skeleton, urine and stool of the rats were collected respectively. The level of lead, calcium and zinc were analyzed by atomic fluoirescence luxmeter. In vitro test： red cells were cultured for two hours, atomic fluorescence luxmeter was used to measure the levels of cell＇s lead, calcium and zinc before and after contamination. Results After the rats were contaminated for four weeks, the lead was excreted mainly through stool and urine. In the organs of experimental animals, lead concentration in the liver was higher than in the blood, and that in the skeleton was the lowest. Compared with those in the control group, lead concentration in the skeleton increase the fastest, which was eight times more. In the urine, calcium and zinc elements excreted increased, but in liver, those two elements＇ levels declined. Calcium and zinc levels in the red ceils decreased significantly as well. Conclusion Organs exposed in the condition contaminated by lead, along with the lead accumulated in the skeleton and liver, led the calcium and zinc lose. The result was identical in vivo test and in vitro. The finding suggests that lead contamination can affect the levels of calcium and zinc in the body.