CHARACTERIZATION OF RENAL NONCYCLOOXYGENASE ARACHIDONATE METABOLISM

肾细胞色素P-450催化花生四烯酸的氧化代谢 酸到环氧二十碳三烯酸(EETs)、欧米伽和欧米伽-1醇(19- 和20-OH-AA)。这些代谢物是这个酶系统所特有的 展示了几种有效的生物活性，包括立体选择性 肾血管收缩，肾小球滤过率降低， 肾上皮细胞对钠和钙离子通透性的改变 钾和对加压素的水渗透反应的调节。 花生四烯酸级联的这一分支对肾脏的意义 功能已经通过a)内源性、 对映体选择性，内毒素的形成，b)酶的调节 实验性高血压涉及的和/或其代谢物，膳食 脱氧皮质类固醇醋酸酯(DOCA)治疗的盐负荷和，c) 细胞色素P-450 4A2基因在高血压中的优势表达 (SHR)大鼠。最近，EET被证明是内源性的 人体肾脏的成分及其增加的尿排出量 妊娠高血压综合征提示肾脏细胞色素P-450可能 在肾脏生理和/或方面发挥尚未确定的作用 病理生理学。作为多学科和全面的 描述这一代谢途径对 肾功能，本项目建议使用标准的方法 蛋白质纯化、酶学、免疫化学、层析和 气质联用：1)继续分子、生化和化学 肾脏细胞色素P-450花生四烯酸单加氧酶的特性 异构体及其代谢产物，2)分析功能/生化 肾生理学实验操作后的相关性研究 功能相关的动物治疗方案，3)调查 这些操作在酶和/或调节中的作用 花生四烯酸级联的这一分支的代谢产物，以及4) 利用实验性高血压动物模型确定潜力 细胞色素P-450花生四烯酸的生化关系 肾脏生理学中的代谢和基因控制改变 和病理生理学。据认为，花生四叠纪的这一分支 酸级联是肾脏适应性反应的一个组成部分 与饮食中的盐超载有关，因此可能与 高血压的病理生理学。

Renal cytochrome P-450 catalyzes the oxidative metabolism of arachidonic acid to epoxyeicosatrienoic acids (EETs), omega and omega-1 alcohols (19- and 20-OH-AA). These metabolites are unique to this enzyme system and display several potent biological activities, including stereoselective renal vasoconstriction, reduction in the glomerular filtration rate, alterations in the permeability of renal epithelia to sodium and potassium and, modulation of the hydroosmotic responses to vasopressin. The significance of this branch of the arachidonate cascade to renal function has been highlighted by a) the demonstration of endogenous, enantioselective, formation of EETs, b) the regulation of the enzymes involved and/or their metabolites by experimental hypertension, dietary salt loading of deoxycorticosteroid acetate (DOCA) treatment and, c) the preferential expression of the cytochrome P-450 4A2 gene in hypertensive (SHR) rats. More recently, the demonstration of EET as endogenous constituents of human kidney and their increased urinary excretion during pregnancy induced hypertension suggest that renal cytochrome P-450 may fulfill yet unidentified roles in kidney physiology and/or pathophysiology. As part of a multidisciplinary and comprehensive approach to delineate the significance of this metabolic pathway to kidney function, this project proposes to utilize standard methods of protein purification, enzymology, immunochemistry, chromatography and GC/MS to: 1) continue the molecular, biochemical and chemical characterization of the renal cytochrome P-450 arachidonate monooxygenase isoforms and of their metabolites, 2) analyze functional/biochemical correlations after the experimental manipulation of renal physiology by functionally relevant protocols of animal treatment, 3) investigate the effects of these manipulations in the regulation of the enzymes and/or the metabolites of this branch of the arachidonate cascade, and 4) utilize animal models of experimental hypertension to define potential relationships between the biochemistry of cytochrome P-450 arachidonate metabolism and genetically controlled alterations in kidney physiology and pathophysiology. It is proposed that this branch of the arachidonic acid cascade is an integral part of the adaptive response of the kidneys to a dietary salt overload and, therefore may be involved in the pathophysiology of hypertension.