RENAL MINERAL DELIVERY

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 最近的研究表明，钙肾结石形成者的肾乳头中有磷酸钙(磷灰石)沉积，这是结石的锚点。在草酸钙结石患者中，在间质中发现了矿物质沉积，最初的形成部位是Henle细肢的基底膜。在其他地方，通常是磷酸钙结石，结晶沉积物位于终端收集管道中。高尿钙促进特定部位矿物质沉积的机制尚不清楚。该项目的目的是了解钙肾结石患者肾脏磷灰石斑块形成的驱动力，以及刷石结石形成过程中收集管、晶体形成的驱动力。为此，我们研究了一组高钙尿性结石形成者和可比的非结石形成者。所有受试者都在GCRC住了14个小时，在那里他们被喂以3种由CRC营养师设计的定义膳食，以改变蛋白质和碳水化合物的含量，但具有等量的钙、磷和钠。在每次尿液结束时和每次餐后2小时的中点采集1小时尿样和采血。测定血、尿矿物质水平，以及甲状旁腺素、骨化三醇和胰岛素水平。我们还测量了计算尿液相对于草酸钙和磷酸钙的过饱和度所需的所有尿液因子，以及每个尿液抑制结晶形成的能力，这是尿液结晶抑制物水平的指标。对性别、年龄、内生肌酐清除量、身高和体重进行适当调整后，对结果进行分析。

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. Recent work has shown that calcium kidney stone formers have deposits of calcium phosphate (apatite) in their renal papillae, which serve as anchor points for stones. In patients calcium oxalate stones, mineral deposits are found in the interstitium, and the initial site of formation is the basement membrane of the thin limbs of Henle. In others, usually calcium phosphate stone formers, crystal deposits are located in the terminal collecting ducts. The mechanisms by which high urine calcium promotes mineral deposition at specific sites are not known. The objective of the project is to understand the driving forces for the formation of apatite plaque in the kidneys of patients with calcium kidney stones and the forces driving collecting duct.crystal formation in in brushite stone formers. For this purpose, we studied a group of hypercalciuric stone formers and comparable non-stone formers. All subjects were admitted to the GCRC for 14 hours, where they were fed 3 defined meals designed by the CRC dietician to vary with respect to protein and carbohydrate content, but to have equivalent amounts of calcium, phosphate and sodium. One hour urine samples were collected and blood samples were draw at the end of each urine and at the mid-points of the first 2 hours after each meal. Serum and urine mineral levels were determined, as well as PTH, calcitriol and insulin levels. We have also measured all urine factors needed to calculate urine supersaturation with respect to calcium oxalate and calcium phosphate, and as well the ability of each urine to inhibit crystal formation, an indicator of the level of urinary inhibitors of crystallization. Results were analyzed with appropriate adjustment for sex, age, creatinine clearance, height and weight.