BONE LEAD STORES AND PREGNANCY INDUCED HYPERTENSION

描述(改编自《调查者摘要》)：由妊娠引起的 高血压和先兆子痫仍然是胎儿和母亲的主要原因 发病率和死亡率，高达10%的怀孕发生在 美国。他们是第一个和青少年中的一个特别的问题 怀孕。这项拟议的研究将调查 怀孕五大因素：血压、血液的时间变化 铅、膳食钙摄入量、当前铅摄入量和骨铅 动员。大鼠在怀孕前、怀孕期间将暴露在铅中 怀孕，或同时怀孕，并将喂食含有低或低的饮食 正常的怀孕期间的钙浓度。控制组 怀孕的大鼠不会暴露在铅中，非怀孕的动物也会 被研究。要测量的变量包括收缩压、血压、 以及骨铅浓度和甲状旁腺激素的血清浓度， 骨钙素，以及25和1，25二羟基维生素D。 妊娠晚期血铅是否自然升高的测定 会导致妊娠高血压综合征。它还将允许 评估当前铅暴露与骨铅接触的相对影响 孕期血铅和血压的动员。这些 研究的重点将是量化血铅/血压之间的关系 影响这一关系的因素及其影响因素 在怀孕期间。补钙有益的观念 怀孕期间并不是什么新鲜事。然而，拟议的研究利用了铅 暴露作为研究预防机制是否增加的一种方式 孕期饮食钙引起的血压是通过抑制铅引起的 从饮食中吸收和/或抑制骨铅动员。 因此，这些研究可以解释其他研究结果的可变性 评估钙和钙的独立影响的调查 怀孕期间铅对血压的影响。

DESCRIPTION (Adapted from the Investigator's Abstract): Pregnancy-induced hypertension and preeclampsia remain leading causes of fetal and maternal morbidity and mortality, occurring in as many as 10% of pregnancies in the United States. They are a particular problem in first and adolescent pregnancies. The proposed study will investigate relationships during pregnancy among five factors: blood pressure, temporal changes in blood lead, dietary calcium intake, current lead ingestion, and bone lead mobilization. Rats will be exposed to lead prior to pregnancy, during pregnancy, or at both times, and will be fed a diet containing a low or normal concentration of calcium during pregnancy. Control groups of pregnant rats will not be exposed to lead and non-pregnant animals will also be studied. Variables to be measured include systolic blood pressure, blood and bone lead concentrations, and serum concentrations of parathormone, osteocalcin, and 25 and 1,25 dihydroxyvitamin D. The study will allow determination of whether the natural rise in blood lead late in pregnancy contributes to pregnancy-induced hypertension. It will also permit assessment of the relative effects of current lead exposure versus bone lead mobilization on blood lead and blood pressure during pregnancy. These studies will focus on quantifying blood lead/blood pressure relationships in the rat and investigation of factors that may influence this relationship during pregnancy. The concept that calcium supplementation is beneficial during pregnancy is not new. However, the proposed studies utilize lead exposure as a way to study if the mechanism of prevention of increases in blood pressure by dietary calcium during pregnancy is by suppression of lead absorption from the diet and/or suppression of bone lead mobilization. Thus, these studies may explain the variability of the results of other investigations that have assessed the independent effects of calcium and lead on blood pressure during pregnancy.