Evidence for net renal tubule oxalate secretion in patients with calcium kidney stones
Evidence for net renal tubule oxalate secretion in patients with calcium kidney stones
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DOI：
10.1152/ajprenal.00411.2010
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发表时间：
2011-02-01
影响因子：
4.2
通讯作者：
Coe, Fredric L.
中科院分区：
文献类型：
--
作者：
Bergsland, Kristin J.;Zisman, Anna L.;Coe, Fredric L.
Bergsland KJ，Zisman AL，Asplin Jr，Wocester EM，Coe FL。钙性肾结石患者肾小管草酸净分泌的证据。Am J Physiol肾脏Physiol 300：F311-F318,2011。2010年12月1日首次出版；DOI：10.1152/ajprenal.00411.2010。-对特发性高钙尿症(IH)患者草酸盐的肾脏处理知之甚少。为了探讨肾小管草酸处理在高血压病中的作用，并评估高血压病和正常对照组之间是否存在差异，我们研究了19名高血压患者、8名正常患者和2名肥胖结石患者(BSF)，在为期一天的综合临床研究中心方案中采用低草酸饮食。在受试者禁食期间和进食三餐后，尿样和血样每隔30到60分钟采集一次，这些食物提供了已知数量的钙、磷、钠、蛋白质、草酸盐和卡路里。在禁食和进食状态下，患者(包括IH和BSF)和对照组之间的血浆草酸浓度和草酸过滤负荷相似。无论进食状态如何，患者的尿草酸排泄量均显著高于对照组。19例IH患者中有6例和两组患者的草酸排泄分数(FEOx)均为>；1，提示有管状草酸分泌，而无对照组(P<；0.00001)。对沿肾单位的水提取进行调整后，患者的尿草酸上升速度比正常受试者更快，同时血浆草酸增加。我们的研究发现，肾小管分泌草酸是钙结石患者高草酸尿症的关键介质，可能是维持血浆草酸在较小范围内的一种手段。
Bergsland KJ, Zisman AL, Asplin JR, Worcester EM, Coe FL. Evidence for net renal tubule oxalate secretion in patients with calcium kidney stones. Am J Physiol Renal Physiol 300: F311-F318, 2011. First published December 1, 2010; doi:10.1152/ajprenal.00411.2010.-Little is known about the renal handling of oxalate in patients with idiopathic hypercalciuria (IH). To explore the role of tubular oxalate handling in IH and to evaluate whether differences exist between IH and normal controls, we studied 19 IH subjects, 8 normal subjects, and 2 bariatric stone formers (BSF) during a 1-day General Clinical Research Center protocol utilizing a low-oxalate diet. Urine and blood samples were collected at 30- to 60-min intervals while subjects were fasting and after they ate three meals providing known amounts of calcium, phosphorus, sodium, protein, oxalate, and calories. Plasma oxalate concentrations and oxalate-filtered loads were similar between patients (includes IH and BSF) and controls in both the fasting and fed states. Urinary oxalate excretion was significantly higher in patients vs. controls regardless of feeding state. Fractional excretion of oxalate (FEOx) was >1, suggesting tubular secretion of oxalate, in 6 of 19 IH and both BSF, compared with none of the controls (P < 0.00001). Adjusted for water extraction along the nephron, urine oxalate rose more rapidly among patients than normal subjects with increases in plasma oxalate. Our findings identify tubular secretion of oxalate as a key mediator of hyperoxaluria in calcium stone formers, potentially as a means of maintaining plasma oxalate in a tight range.