Skeletal Changes during Pregnancy and Lactation in the Rat: Effect of Different Levels of Dietary Calcium
Skeletal Changes during Pregnancy and Lactation in the Rat: Effect of Different Levels of Dietary Calcium
复制标题
大鼠妊娠期和哺乳期骨骼变化：不同膳食钙水平的影响
DOI：
--
复制
发表时间：
1952
影响因子：
3.6
通讯作者：
M. H. Quenouille
中科院分区：
文献类型：
--
作者：
G. M. Ellinger;J. Duckworth;A. Dalgarno;M. H. Quenouille
现在众所周知，骨骼是钙和磷的储存库，哺乳期所需的一部分矿物质是通过骨吸收来满足的。在早期的通信（Warnock & Duckworth，1944）中，对文献进行了调查，并在摄入足够钙的条件下研究了海绵体作为哺乳期矿物质来源的作用。关于哺乳期骨吸收和哺乳后骨修复的一些有趣问题仍然没有答案。首先，骨骼对哺乳需要的反应在多大程度上受到钙摄入水平差异的影响是未知的。其次，尚未研究松质骨和密质骨在哺乳期被单独吸收的程度，以及这些变化在多大程度上可以通过钙摄入量的改变来改变。第三，钙的摄入量在多大程度上影响了松质骨和密质骨在消耗后的恢复能力，这一点似乎还没有得到研究。第四，尚不清楚骨的再吸收是否是钙缺乏动物从骨骼储存中释放矿物质以满足泌乳需要的唯一过程。还必须考虑骨脱矿的可能性，即提取矿物质成分而不吸收有机基质。最后，似乎还没有研究过接受钙含量不同饮食的怀孕和哺乳动物骨骼物理尺寸的变化。本实验旨在回答这些问题，并提供一个机会，研究不同的膳食钙水平对大鼠的生殖性能和他们的能力，其抚养后代的影响。日粮由天然饲料组成，选择低钙含量。这一领域的大多数早期研究者使用合成饮食。
It is now well known that the skeleton serves as a store of calcium and phosphorus, and that a part of the mineral requirements of lactation is met by bone resorption. In an earlier communication (Warnock & Duckworth, 1944) the literature was surveyed and the role of the spongiosa as a source of minerals for lactation in the rat was studied under conditions of adequate calcium intake. Certain interesting questions about the resorption of bone in lactation and its subsequent repair after lactation remain unanswered. In the first place, the extent to which the response of the skeleton to lactational needs is modified by differences in the level of calcium intake is unknown. Secondly, the extent to which cancellous and compact bone are individually resorbed in lactation and the degree to which these changes can be modified by alterations in calcium intake have not been studied. Thirdly, the extent to which calcium intake affects the capacity of cancellous bone and compact bone to recover after depletion does not seem to have been examined. Fourthly, it is not clear whether resorption of bone is the only process by which minerals are released from skeletal stores to meet the needs of lactation in the calciumdeficient animal. The possibility of demineralization of bone, that is of extraction of the mineral component without resorption of the organic matrix, must also be considered. Finally, it seems that no study has been made of changes in physical dimensions of bone in pregnant and lactating animals receiving diets differing in their calcium content. The present experiment was designed to answer these questions and to afford an opportunity to study the effects of different dietary calcium levels on the reproductive performance of rats and their ability to rear their young. The diets were composed of natural feeding-stuffs, selected for their low calcium content. Most earlier investigators in this field used synthetic diets.