CALCIUM-OXALATE INTERACTION IN MODULATION OF STONE FORMATION

草酸钙相互作用调节结石形成

• 批准号: 7606320
• 负责人: MARGARET S. PEARLE
• 金额: $ 2.01万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2007-09-16
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7606320
• 关键词: Address; Affect; Attenuated; Binding; Calcium; Calcium Oxalate; Calculi; Complex; Computer Retrieval of Information on Scientific Projects Database; Dietary Calcium; Excretory function; Food; Funding; Grant; Institution; Intake; Intestinal Absorption; Intestines; Left; Oxalates; Process; Research; Research Personnel; Resources; Source; Testing; United States National Institutes of Health; Urine; absorption; base; falls; hypercalciuria; interest; urinary

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project addresses a topic that has raised considerable interest recently, dealing with the possibility that dietary calcium restriction is either ineffective or may exaggerate stone formation. The basis for this concern is the so-called calcium-oxalate interaction that occurs in the bowel and in urine. We were among the first to describe oxalate-calcium interaction in the bowel, i.e., changes in urinary oxalate excretion from binding of oxalate by calcium in the intestinal tract. During low calcium intake, there is inadequate luminal calcium to bind oxalate, increasing oxalate absorption and urinary oxalate. In AH, urinary oxalate may be mild-moderately increased, because increased intestinal absorption of calcium leaves insufficient amount of calcium to bind oxalate. A high calcium intake would be expected to eliminate or attenuate the rise in urinary oxalate. The limiting factor is dietary oxalate content, since it is dietary oxalate that is bound by luminal calcium. This component is directed at elucidating the "calcium-oxalate interaction", a process by which calcium affects the amount of total oxalate in urine by binding oxalate in the intestinal tract, as well as the amount of ionic oxalate in urine by complexing oxalate. By this process, calcium restriction could increase urinary oxalate, attenuating the decline in urinary saturation of calcium oxalate that might ensue from the fall in urinary calcium. Conversely, a high calcium intake could lower total and ionic oxalate in urine, opposing the rise in urinary saturation of calcium oxalate that might occur from increased urinary calcium. The overall hypothesis to be tested is that calcium-oxalate interaction is dependent on dietary oxalate restriction, the state of intestinal absorption of calcium or the degree of hypercalciuria, and on whether calcium is provided as food or supplement. The objective of this component is to complete remaining studies required to test the above hypothesis.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 这个项目解决了一个最近引起相当大兴趣的话题，即饮食钙限制要么无效，要么可能会加剧结石形成。这种担忧的基础是发生在肠和尿中的所谓的草酸钙相互作用。我们是最早描述肠内钙离子相互作用的人之一，即，肠道中草酸盐与钙结合导致尿草酸盐排泄的变化。 在低钙摄入期间，管腔钙不足以结合草酸盐，增加草酸盐吸收和尿草酸盐。在AH中，尿草酸盐可能轻度-中度增加，因为增加的钙的肠吸收留下不足量的钙结合草酸盐。预计高钙摄入量可消除或减弱尿草酸盐的升高。限制因素是膳食草酸盐含量，因为它是膳食草酸盐是由鲁米那钙结合。 本部分旨在阐明“钙-草酸盐相互作用”，这是一个钙通过在肠道中结合草酸盐影响尿液中总草酸盐量以及通过络合草酸盐影响尿液中离子草酸盐量的过程。通过这一过程，钙限制可以增加尿草酸盐，减轻可能由尿钙下降引起的尿草酸钙饱和度下降。相反，高钙摄入量可降低尿液中的总草酸盐和离子草酸盐，与尿钙增加可能导致的尿草酸钙饱和度升高相反。有待检验的总体假设是，钙-草酸盐相互作用取决于饮食中草酸盐的限制、钙的肠道吸收状态或高钙尿症的程度，以及钙是否作为食物或补充剂提供。 本部分的目的是完成检验上述假设所需的其余研究。