DIURNAL VARIATION OF URINARY PH

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。尿酸结石患者中最不变的特征是尿液pH值异常低(&lt；5.5)。间歇性地在非结石患者中检测到这样的值，然而，出现在昼夜节律模式中的pH值的周期性变化似乎保护了正常受试者免受肾结石的影响。初步研究表明，尿酸结石患者的尿液pH值持续较低，没有昼夜波动，因此容易出现尿酸沉淀。假设：1)正常人的尿液pH、血浆和尿酸碱参数存在昼夜节律变化。2)胃排空变异部分与胃液分泌有关。3)尿酸结石患者的这种昼夜节律改变。这些假说将通过实现以下目标来验证：1)确定正常受试者是否存在尿液pH和血浆/尿酸碱参数状态的周期性变化，以及尿酸结石患者是否存在不同的周期性变化。2)探讨无论是正常人还是尿酸结石患者，胃酸的昼夜变化是否与胃酸分泌有关，并因此被质子泵抑制剂所改变。

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. The most invariant feature found among uric acid stone formers is an abnormally low urinary pH (<5.5). Intermittently, such values are detected in non stone formers, however, cyclical variation in pH that occur in a circadian pattern appear to protect normal subjects from nephrolithiasis. Preliminary stuies suggest that uric acid stone formers maintain a persistently low urine pH, without dirunal fluctuations, and because of this environment are predisposed to uric acid precipitation. Hypotheses: 1) There is a circadian variation in urine pH, and plasma and urinary acid-base parameters in normal subjects. 2) Part of the dirunal variation is ude to gastric secretion. 3) This circadian profile is altered in uric acid stone formers. The hypotheses will be tested by achieving the following objectives: 1) define whether cyclic variation in urine pH and plasma/urine acid base parameters status exists in normal subjects and whether it differs in uric acid stone formers. 2) explore if the diurnal variation is due to gastric acid secretion and thus modified by the administration of a proton pump inhibitor, both in normal subjects and uric acid stone formers.