Effects of lead exposure before pregnancy and dietary calcium during pregnancy on fetal development and lead accumulation.
Effects of lead exposure before pregnancy and dietary calcium during pregnancy on fetal development and lead accumulation.
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DOI：
10.1289/ehp.00108527
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发表时间：
2000-06
影响因子：
10.4
通讯作者：
Bogden JD
中科院分区：
文献类型：
--
作者：
Han S;Pfizenmaier DH;Garcia E;Eguez ML;Ling M;Kemp FW;Bogden JD
数百万育龄妇女由于儿童时期接触铅而有大量骨铅储存。在铅暴露的同时摄入膳食钙可以减少铅的吸收和积累。然而，膳食钙对先前积累的母体铅储存和转移到胎儿的影响还没有调查。我们研究了雌性大鼠早期铅暴露对随后妊娠期间胎儿发育的影响。我们向5周龄雌性Sprague-Dawley大鼠的饮用水中添加铅作为醋酸盐，持续5周;对照组接受等摩尔醋酸钠。随后是交配前1个月的无铅暴露期。我们将妊娠大鼠（n = 39）随机分配至妊娠期间钙含量不足（0.1%）或正常（0.5%）的饮食中。总共有345只幼仔存活。铅暴露的母鼠及其幼崽的血铅浓度明显高于对照组，但浓度在许多孕妇的范围内。在怀孕期间喂食缺钙饮食的母鼠所生的幼崽比喂食0。5%的钙饮食。与对照组相比，铅暴露母鼠所生幼鼠的平均出生体重和出生身长显著（p<0.0001）降低。母鼠或幼鼠器官铅浓度与出生体重或身长之间存在显著的单变量负相关。0.5%钙饮食没有增加子宫生长。逐步回归分析表明，较大的窝产仔数和雌性与幼崽出生体重和身长的降低显著相关。然而，在妊娠前结束的铅暴露与出生体重和身长的降低显著相关（p<0.0001），即使在胎仔数、幼崽性别和妊娠期间母鼠体重增加被纳入回归分析后。这些数据表明，在怀孕期间增加膳食钙可以减少胎儿铅的积累，但不能防止铅诱导的出生体重和长度的减少。研究结果提供了证据，表明饮食营养素可以影响怀孕期间毒素向胎儿的转移。如果这些结果适用于女性，怀孕期间饮食钙的增加可能会减少孕前母体暴露于胎儿的铅转移。
Millions of women of child-bearing age have substantial bone lead stores due to lead exposure as children. Dietary calcium ingested simultaneously with lead exposure can reduce lead absorption and accumulation. However, the effects of dietary calcium on previously accumulated maternal lead stores and transfer to the fetus have not been investigated. We studied the effects of lead exposure of female rats at an early age on fetal development during a subsequent pregnancy. We gave 5-week-old female Sprague-Dawley rats lead as the acetate in their drinking water for 5 weeks; controls received equimolar sodium acetate. This was followed by a 1-month period without lead exposure before mating. We randomly assigned pregnant rats (n = 39) to diets with a deficient (0.1%) or normal (0.5%) calcium content during pregnancy. A total of 345 pups were delivered alive. Lead-exposed dams and their pups had significantly higher blood lead concentrations than controls, but the concentrations were in the range of those found in many pregnant women. Pups born to dams fed the calcium-deficient diet during pregnancy had higher blood and organ lead concentrations than pups born to dams fed the 0. 5% calcium diet. Pups born to lead-exposed dams had significantly (p<0.0001) lower mean birth weights and birth lengths than controls. There were significant inverse univariate associations between dam or pup organ lead concentrations and birth weight or length. The 0.5% calcium diet did not increase in utero growth. Stepwise regression analysis demonstrated that greater litter size and female sex were significantly associated with reduced pup birth weight and length. However, lead exposure that ended well before pregnancy was significantly (p<0.0001) associated with reduced birth weight and length, even after litter size, pup sex, and dam weight gain during pregnancy were included in the regression analysis. The data demonstrate that an increase in dietary calcium during pregnancy can reduce fetal lead accumulation but cannot prevent lead-induced decreases in birth weight and length. The results provide evidence that dietary nutrients can influence the transfer of toxins to the fetus during pregnancy. If these results are applicable to women, an increase in diet calcium during pregnancy could reduce the transfer of lead from prepregnancy maternal exposures to the fetus.