FUNCTIONAL SIGNIFICANCE OF CYTOCHROME P450 CYCLOOXYGENASE

20-羟基二十碳四烯酸（20-HETE）是关键肾结构的主要类二十烷酸，其中它在肾血管和肾小管功能的调节中起重要组分的作用。鉴于20-HETE对肾功能的重要性，对控制20-HETE的产生和活性的那些因素的鉴定和表征具有高度优先性，因为它们决定了类二十烷酸的肾作用的深度和广度。环氧合酶（考克斯-1和考克斯2）和一氧化氮合酶（NOS）已被确定为分别调节20-HETE代谢和产生的中心。三个目的将阐述考克斯和NO对肾脏中20-HETE水平和活性的假定重要性。目的1建立高血压AII输注模型，探讨细胞因子NO和考克斯（1和2）对20-HETE产生和生物学活性的影响及其相互关系。目的2利用高盐摄入对NO产生和低盐摄入对皮质考克斯-2表达的相对选择性作用，以研究它们对20-HETE组织水平和皮质中20-HETE代谢物的生物活性谱的单独作用。目的3：阐明糖皮质激素对TAL中考克斯- 2表达的强大负面影响，以确定涉及TNF和考克斯-2（可能还有iNOS）肾上腺后的相互作用，并将这些因素中的一种或多种与假定的CYP 450 AA代谢抑制和肾功能变化相关。

20-hydroxyeicosatetraenoic acid (20-HETE) is the principal eicosanoid of key renal structures where it serves an essential component in the regulation of renal vascular and tubular function. In view of the importance of 20-HETE to renal function, the identification and characterization of those factors that govern production and activity of 20-HETE assume a high priority as they determine the depth and breadth of the renal actions of the eicosanoid. Cyclooxygenases (COX-1 and COX 2) and nitric oxide synthases (NOS) have been identified as being central to the regulation of 20-HETE metabolism and production, respectively. Three Aims will address the postulated importance of COX and NO to 20-HETE levels and activities in the kidney. AIM 1 makes of the AII infusion model of hypertension to determine relationship and possible interactions of cytokines, NO and COX (both-1 and -2) that affect production and biological activities of 20-HETE. Aim 2 draws upon the relatively selective effect of high salt intake on NO production and low salt intake on cortical COX-2 expression in order to study their separate effects on 20-HETE tissue levels and spectrum of biological activities of 20-HETE metabolites in the cortex. AIM 3 addresses the powerful negative effect of glucocorticoids on COX- 2 expression in the TAL in order to define interactions involving TNF and COX-2 (and possibly iNOS) post-adrenal and to relate one or more of these factors to a postulated depression of CYP450 AA metabolism and to changes in renal function.