HETEROGENEITY CELL CALCIUM DISTRIBUTION RENAL HYPOXIA

我们的长期目标是确定钙在 导致肾脏缺血细胞损伤的早期事件。要做到这一点，它是 对于确定释放、摄取和结合的位置至关重要 细胞内的钙。电子探针X射线微区分析 (EPXMA)提供无与伦比的元素测量方法 在单个细胞和亚细胞细胞器内的内容物，从而 局部钙量的变化可以在以下位置定量 在导致不可逆电池的时间过程中选择的间隔 受伤。EPXMA用于近端肾小管的初步实验 在细胞内表现出很大程度的异质性 和细胞内钙的分布。这种异质性 使之前的许多研究受到质疑，这些研究已经 假设有一个更均匀的分布。 近端小管悬吊便于实验 允许检查最早事件的演习 导致不可逆的细胞损伤并消除继发性 在一个完整的动物模型中，由于妥协而产生的影响 TOTO患者肾血管系统的功能。我们会 同时进行实验，测量生物化学， 生理、超微结构和微化学变量 同样的停职。实验条件也将被检验。 在缺氧期间保护肾功能，例如存在 腺嘌呤核苷酸、甘露醇和洗澡时的低pH 5~6成熟。将进行实验以测量细胞质 甲酯染料(Fura-2)在相同条件下的游离钙 条件。将使用EPXMA来验证这些测量 通过测定染料的隔间作用。这个强大的 技术(EPXMA)明智地应用于特征良好的 肾制剂，结合已建立的 生理、生化和超微结构测量，是 预计将提供有关以下方面的独特直接信息 钙在肾脏缺氧细胞损伤中的作用。

Our long range goal is to define the role which calcium plays in early events leading to renal ischemic cell injury. To do so, it is vital to identify the sites of release, uptake and binding of calcium within the cells. Electron probe x-ray microanalysis (EPXMA) offers and unexcelled means of measuring elemental contents within individual cells and subcellular organelles, so that changes in the amounts of localized calcium can be quantitated at chosen intervals during the time course leading to irreversible cell injury. Preliminary experiments using EPXMA in proximal tubules have demonstrated a large degree of heterogeneity in the cellular and intracellular distribution of calcium. Such heterogeneity brings into question numerous previous studies which have assumed that there is a more homogeneous distribution. The proximal tubule suspension facilitates experimental maneuvers which permit examination of the earliest events leading to irreversible cell damage and eliminates secondary effects that, in an intact animal model, arise from compromising the function of the renovascular system in toto. We shall perform, in parallel, experiments which will measure biochemical, physiological, ultrastructural and microchemical variables on the same suspension. Experimental conditions will also be examined that preserve renal function during anoxia, such as the presence of adenine nucleotides, mannitol, and low pH in the bathing medium. Experiments will be performed to measure cytosolic free calcium using methyl ester dyes (fura-2) under identical conditions. EPXMA will be used to validate these measurement by determining the compartmentation of the dyes. This powerful technique (EPXMA) judiciously applied to a well-characterized renal preparation, in combination with the established array of physiological, biochemical, and ultrastructural measurements, is expected to provide unique direct information on the role of calcium in hypoxic cell injury in the kidney.