CELLULAR PATHOPHYSIOLOGY OF ACUTE RENAL FAILURE

该项目的总体目标是改善 了解肾脏的细胞病理生理学 缺血性急性期近曲小管细胞损伤 肾衰竭 通过以下方法制备近端小管的悬浮液： 胶原酶处理兔肾脏及其代谢 特征，特别是呼吸，细胞阳离子稳态 和细胞腺嘌呤核苷酸稳态，在模型中进行了研究， 缺氧损伤，目前已得到很好的定义。 我们 已经发现有几种方法可以显著改变 缺氧引起的损伤。 它们是：以高密度孵育小管，降低 从7.4到7.0或更低的孵育培养基， 含有高浓度外源性腺嘌呤核苷酸的小管 用甘氨酸或谷胱甘肽处理肾小管。 进一步 这些特征和机制的描述 影响可以提供工具，以批判性地评估哪些 许多可能的病理生理过程和亚细胞部位 损伤在氧的发病机制中实际上是重要的 剥夺诱导肾小管细胞损伤，并可以帮助引导 用于改善肾小管细胞损伤的方法的开发 vivo. 在下一个融资期内，我们将集中 在三个方面下功夫。 1)有效的细胞保护作用， 甘氨酸将被研究，以更完整地定义氧 剥夺和复氧条件下，甘氨酸是 保护性的，肾小管细胞内甘氨酸活性的位点， 其对离体肾小管保护作用的特异性 准备和缺氧引起的损伤， 甘氨酸代谢的途径，这是保护。 （二） 我们将继续研究高剂量的 外源核苷酸的相对程度，以澄清 由不同的嘌呤提供保护。 3)我们将分析 通过直接测量降低pH值的主要保护作用 细胞溶质pH和培养基的独立操作， 胞质pH值。在快速的细胞周期中， 缺氧诱导的发展过程中的时间弗拉姆 肾小管细胞损伤使得能够直接评估 如果对病理生理学的可靠见解 要获得。 本提案中的研究提供了一个既定的 和通用的方法来实现这一点。

The general aims of this project have been to improve understanding of the cellular pathophysiology of the renal proximal tubule cell injury which occurs during ischemic acute renal failure. Suspensions of proximal tubules are prepared by collagenase treatment of rabbit kidneys and their metabolic characteristics, particularly respiration, cell cation homeostasis and cell adenine nucleotide homeostasis, are studied in models of oxygen deprivation injury which have now been well defined. We have found that several maneuvers strikingly alter the sensitivity of the isolated tubules to oxygen deprivation-induced injury. These are: incubating tubules at high density, lowering the pH of the incubation medium from 7.4 to 7.0 or less, treating the tubules with high concentrations of exogenous adenine nucleotides and treating the tubules with glycine or gluthatione. Further delineation of the characteristics and mechanisms of these effects can provide the tools for critically assessing which of many possible pathophysiologic processes and subcellular sites of damage are actually important in the pathogenesis of oxygen deprivation-induces tubule cell injury and can help guide the development of methods for ameliorating tubule cell injury in vivo. During the next period of funding we will concentrate our work on three areas. 1) The potent, cytoprotective effects of glycine will be studied to more completely define the oxygen deprivation and reoxygenation conditions under which glycine is protective, the sites within the tubule cell of glycine's activity, the specificity of its protective effects for the isolated tubule preparation and oxygen deprivation-induced injury and the pathways of glycine metabolism which account for protection. 2) We will extend our studies of the protective effects of high doses of exogenous nucleotides to clarify the relative degrees of protection provided by different purines. 3) We will analyze the major protective effect of reducing pH by direct measurements of cytosolic pH and independent manipulations of medium and cytosolic pH. The interplay of multiple processes over a rapid time fram during the development of oxygen deprivation-induced tubule cell injury makes it important to be able to directly assess and manipulate them if reliable insights into pathophysiology are to be obtained. The studies in this proposal provide an established and versatile approach for achieving this.