LIPIDS AND UROLITHIASIS

描述（改编自申请人摘要）：尿结石 它是一种常见的人类疾病，约占医院 在美国的招生。 据估计，仅在美国， 治疗与结石有关的疾病至少花费24亿美元， 美元/年。 复发率高达60%，三分之一的患者 复发性肾结石患者可能会失去受累的肾脏。 七十到 80%的结石含有草酸钙（CaOx）。 初始事件 在泌尿系结石形成中，晶体成核作用被确定为 异质的 细胞降解产物和膜结合囊泡 常见于哺乳动物尿液和钙化性尿结石中。 膜结合 囊泡可以诱导成核，其被确定为磷酸盐（CaP）， 体外CaOx。 在大鼠肾脏中产生的CaP和CaOx晶体都是 几乎总是与膜囊泡一起形成。 基于 这些观察结果表明，尿中钙化晶体的成核作用， 是由细胞膜及其脂质介导的。 然而，并非所有的囊泡都具有成核的能力 晶体 显然，在膜表面有特定的区域， 只有具有这些结构域的囊泡才能诱导晶体成核。 什么 这些是域吗？ 它们是如何变得对 肾小管液还是尿液 这个项目的目标是找到答案， 这些问题和相关问题， 膜相关钙结晶机制 含有晶体。 在雄性SD大鼠中诱导CaOx晶体形成和肾结石形成 大鼠 与尿和肾结晶事件相关的脂质将被 分离并鉴定以确定任何特异性。 CaOx晶体 将通过在体外将膜囊泡在 CaOx的亚稳溶液。 晶体相关囊泡将被分离 通过密度梯度离心从非晶体缔合囊泡中分离。 将分离和鉴定两种类型囊泡的脂质。 到 研究各种磷脂的作用，含有 将制备特定的脂质组合，并研究它们在成核和 将检查CaOx晶体的生长。

DESCRIPTION (Adapted from the Applicant's Abstract): Urinary stone formation is a common human disease accounting for about 1% of hospital admissions in the United States. It is estimated that in the US alone, treatment of the stone related disorders cost at least 2.4 billion dollars/year. Recurrence rate is up to 60% and one third of the patients with recurrent kidney stones may lose the involved kidney. Seventy to eighty percent of the stones contain calcium oxalate (CaOx). Initial event in urinary stone formation is crystal nucleation which is determined to be heterogeneous. Cellular degradation products and membrane bound vesicles are common in mammalian urine and calcific urinary stones. Membrane bound vesicles can induce nucleation which is determined to be phosphate (CaP) and CaOx in vitro. Both CaP and CaOx crystals produced in rat kidneys are almost always formed in association with the membranous vesicles. Based on these observations nucleation of calcific crystals in urine is proposed to be mediated by cellular membranes and their lipids. All vesicles may however not be endowed with the capabilities to nucleate crystals. Apparently there are specific domains on membrane surfaces and only the vesicles with those domains can induce crystal nucleation. What are those domains? How do they become available to the contents of the renal tubular fluid or urine? Goals of this project are to find answers to these and related questions and to develop an understanding of the mechanisms involved in membrane associated crystallization of calcium containing crystals. CaOx crystalluria and nephrolithiasis will be induced in male Sprague-Dawley rats. Lipids associated with the urinary and renal crystal events will be isolated and identified to determine any specificity. CaOx crystal formation will be induced in vitro by incubation of membrane vesicles in a metastable solution of CaOx. Crystal associated vesicles will be separated from the non-crystal associated vesicles by density gradient centrifugation. Lipids of both types of vesicles will be isolated and identified. To investigate actions of various phospholipids, Langmuir monolayers containing specific lipid combinations will be made and their role in nucleation and growth of CaOx crystals will be examined.