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 酸转化为环氧二十碳三烯酸（E2）、ω和ω-1醇（19- 和20-OH-AA）。 这些代谢物是这种酶系统所特有的， 显示出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， 改变肾上皮细胞对钠的渗透性， 钾和对加压素的水渗透反应的调节。 花生四烯酸级联反应的这一分支对肾损害的意义 功能突出表现在：a）内生性， 对映选择性的，E2的形成，B）酶的调节 参与和/或其代谢产物的实验性高血压，饮食 醋酸脱氧皮质类固醇（DOCA）治疗的盐负荷，和，c） 细胞色素P-450 4A 2基因在高血压病中的优先表达 (SHR)大鼠 最近，EET是内源性的， 人肾的成分和他们增加尿排泄期间 妊娠高血压综合征提示肾细胞色素P-450可能 在肾脏生理学中发挥尚未确定的作用，和/或 病理生理学 作为多学科和全面的 方法来描绘这一代谢途径的意义， 肾功能，该项目建议利用标准方法， 蛋白质纯化、酶学、免疫化学、色谱和 GC/MS：1）继续分子、生化和化学 肾细胞色素P-450花生四烯酸单加氧酶的特性 异构体及其代谢物，2）分析功能/生化 实验操作后的肾生理学的相关性， 功能相关的动物治疗方案，3）调查 这些操作在酶调节中的作用和/或 花生四烯酸级联的该分支的代谢物，和4） 利用实验性高血压的动物模型来确定潜在的 细胞色素P-450花生四烯酸酯的生化特性与 代谢和遗传控制的肾脏生理学改变 和病理生理学。 有人提出花生四烯酸的这个分支 酸级联反应是肾脏适应性反应的组成部分 饮食中的盐过量，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.