【摘要】 目的探讨环境镉暴露时胎盘组织金属硫蛋白表达的意义。方法于2002年11月~2003年1月选择湖北省某市的待产孕妇,进行问卷调查和体格检查,同时检测全血镉水平;采集新生儿脐血和部分胎盘组织用于测定镉含量。对部分胎盘组织做了免疫组织化学检查,观察胎盘组织MT表达情况;分析胎盘组织MT表达与孕妇镉暴露水平、胎盘镉蓄积及胎盘镉转运关系。结果母血镉波动在0.27~13.00μg/L,其中60.71%超过血镉正常范围的上限(1.2μg/L)。胎盘镉水平波动在0.0325~1.69μg/g干重。所有新生儿脐血镉水平均低于孕母血镉,波动在0.02~2.69μg/L,与母血镉比值的中位数为0.274。Spearman相关分析表明,胎盘镉、脐血镉均与母血镉呈显著正相关(rs=0.450,P<0.01;rs=0.343,P<0.01)。全部研究对象胎盘组织MT表达的阳性率为60%(84/140),多因素logistic逐步回归分析,母血镉与MT表达高度相关(OR=13.822,95%可信区间为2.591~73.719);正常血镉孕妇胎盘组织MT的阳性表达率为47.27%(26/55),高血镉孕妇胎盘组织MT的阳性表达率为68.24%(58/85),层间MT阳性表达率差异有统计学意义(χ2=6.1141,P<0.05)。全部研究对象中进行协方差分析,不同MT表达组间脐血镉/母血镉差异有统计学意义(F=4.13,P<0.05)。结论胎盘对镉具有明显的屏障作用,环境镉暴露能诱导胎盘组织MT的表达。更多还原

【Abstract】 Objective To investigate the significance of metallothionein expression in the placental of population environmental exposed to cadmium.Methods Pregnant women were selected from one city of hubei province between november 2002 and january 2003.Maternal age,parity,gestational age,pregnancy history,and lifestyle data were obtained from questionnaire interview.Whole blood of pregnant women,umbilical cord blood of neonates and placenta were collected and cadmium levels were determined by inductively coupled plasma emission mass spectroscopy.Immunohistochemistry staining,S-P method was used to observe the expression of the MT in placental tissue from 140 cases of human term placenta.To analysis the potential association between MT and placental cadmium or umbilical cord blood cadmium in the pregnant women of environmental exposed to cadmium.Results Maternal blood cadmium ranged from 0.27 to 13.00 μg/L,of which,60.71% was higher than the upper limit of the reference range(1.2 μg/L).Placental cadmium ranged from 0.0325 to 1.69 μg/g dry weight.Cadmium concentrations in umbilical cord blood ranged from 0.02 to 2.69 μg/L,all of which were lower than that in maternal blood.The median of the ratio of umbilical cord blood cadmium to maternal blood cadmium was 0.274.Cadmium in placentas and umbilical cord blood was positively correlated with maternal blood cadmium.Spearman correlation showed that cadmium in placental tissue and umbilical cord blood were both positively correlated with that in maternal blood(r_s=0.450,P<0.01;r_s=0.343,P<0.01).The positive staining for MT observed was 60%(84/140) in the placental tissue of the whole study cases.Multiple logistic regression analysis showed that The expression of MT was significantly associated with maternal blood cadmium levels(OR=13.822 95%CI2.591～73.719).The positive staining for MT observed was 47.27%(26/55),68.24%(58/85)in placental tissue of normal levels and higher levels of maternal blood cadmium.The MT expression of placental tissue was significant differences(χ~2=6.1141,P<0.05).Analysis of covariance showed that the adjusted geometry mean of the ratio of umbilical cord blood cadmium to maternal blood cadmium in the different MT expression group was significant differences(F=4.13,P<0.05).Conclusion Results show that evident barrier is in the placenta to cadmium,and environmental cadmium exposure induces MT expression in placental tissue.更多还原