Modulation of serum parathyroid hormone and ionized calcium concentrations during reproduction in rats fed a low calcium diet.
Modulation of serum parathyroid hormone and ionized calcium concentrations during reproduction in rats fed a low calcium diet.
复制标题
低钙饮食喂养的大鼠在繁殖过程中血清甲状旁腺激素和离子钙浓度的调节。
DOI：
10.1002/jbmr.5650030311
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Toverud,SU
中科院分区：
文献类型：
--
作者：
Garner,SC;Peng,TC;Toverud,SU
使用钙（0.1%Ca）的适度饮食限制来加重血清免疫反应性甲状旁腺激素（iPTH）的变化，这在喂食0.4%Ca饮食的哺乳期大鼠中已有报道。此外，还检查了这种低钙饮食对妊娠、延长哺乳期和断奶期间血清总钙和离子钙以及iPTH的影响。血清总钙与游离钙呈高度正相关（r= 0.88，p <0.001，n = 120）。与未交配对照组相比，妊娠大鼠分娩当天的血清iPTH显著升高（36%），同时总血清钙和离子血清钙均随之降低。分娩后1天内，血清钙已上升到对照水平。在哺乳期的前2周，血清iPTH仍显著升高，并在哺乳期的第3周进一步升高至非哺乳期对照组水平的两倍以上。血清钙在泌乳第二周逐渐下降。当用寄养窝延长哺乳期时，高血清iPTH水平再维持2周。在哺乳期第16天取出哺乳幼仔后6小时内，母体血清离子钙和总钙升高，血清iPTH下降;断奶后24-48小时，所有三个参数均与未交配对照组相似。数据表明，血清离子钙是导致低钙饮食大鼠哺乳期甲状旁腺功能亢进状态的主要因素。
Moderate dietary restriction of calcium (0.1% Ca) was used to accentuate the changes in serum immunoreactive parathyroid hormone (iPTH) that had been reported earlier in lactating rats fed 0.4% Ca diet. In addition, the effects of this low‐Ca diet on serum total and ionized Ca and iPTH during pregnancy, extended lactation, and weaning were examined. The positive correlation between serum total and ionized Ca was highly significant (r= 0.88,p< 0.001,n= 120). Serum iPTH was significantly higher (36%) in pregnant rats on the day of parturition compared to nonmated controls, and there was a concomitant decrease in both total and ionized serum Ca. Within 1 day after parturition, however, serum Ca had risen to the control level. Serum iPTH remained significantly elevated during the first 2 weeks of lactation, and increased further during the third week of lactation to a level more than twice that of nonlactating controls. Serum Ca fell gradually during the second week of lactation. The high serum iPTH levels were maintained for another 2 weeks when lactation was extended with foster litters. Within 6 hr of removal of the suckling pups on day 16 of lactation, maternal serum ionized and total Ca had risen and serum iPTH had fallen; all three parameters were at levels similar to those of nonmated controls by 24–48 hr after weaning. The data suggest that serum ionized Ca is a major factor contributing to the hyperparathyroid state during lactation in rats fed a low‐Ca diet.