CORTICOSTEROID METABOLISM IN JUVENILE HYPERTENSION

这个项目的目标是阐明它的结构、性质、 和11β-羟基类固醇脱氢酶的生化功能，以及 由11-β-脱氢酶和11-氧化还原酶组成的酶系统 组件。该系统在皮质类固醇代谢中起着关键作用。 我们预计，这一计划的成功完成将 洞察11β-羟基类固醇脱氢酶如何 复合体参与血压调节，如何扰乱 它的功能与一种青少年高血压(AME)有关，以及 它是如何通过皮质类固醇代谢的催化来调节细胞的 以及组织的生长和成熟。我们将使用抗体来对抗 均相11β-脱氢酶(11β脱氢酶)组分产生于 兔和11β-二氢脱氢酶的药物抑制剂，如 甘草次酸，用来检验这种酶“保护”的假说 I型受体拮抗11β-受体的盐皮质激素活性 通过将11种β-羟基类固醇氧化为 不活跃的11-氧代形式。研究将在体外进行，以便 探索抑制作用的分子基础，并在体内进行 建立AME动物模型。我们已经确定11β水解酶是一种 糖蛋白。我们将研究它的糖苷结构，以及 碳水化合物成分对酶功能的意义。我们会 使用我们用来产生的单特异性多克隆抗体 均相11β水解酶用于筛选大鼠肝脏表达文库 整合到噬菌体载体中。我们的目标是确定 从结构基因和TO衍生的mRNA的核苷酸序列 由此推导出11β水解酶的一级氨基酸序列。我们会 从人胎盘中分离酶并比较其性质 克隆衍生的多肽和鼠源性的酶。这个 在我们的实验中产生的抗体和DNA将被用作 11β-水解酶组织化学探针法定量研究 抗原及其相关的mRNA在细胞和组织中的表达，并监测 荷尔蒙干预后酶水平的变化。我们计划 为了纯化皮质类固醇11-氧化还原酶，该酶催化 将皮质醇还原为皮质醇，并与11β脱氢酶协同作用 维持类固醇内环境的平衡。经过提纯后， 与11个测试版计划的分析研究类似的分析研究将是 已执行。这些调查将帮助我们了解a)如何 缺乏11β水解酶活性会导致高血压；b) 控制氧化还原的生理机制 皮质类固醇在C-11。

The goals of this project are to elucidate the structure, properties, and biochemical functions of 11 beta-hydroxysteroid dehydrogenase, an enzyme system composed of 11 beta-dehydrogenase and 11-oxoreductase components. This system plays a key role in corticosteroid metabolism. We anticipate that successful accomplishment of this program will provide insight into how the 11 beta-hydroxysteroid dehydrogenase complex participates in blood pressure regulation, how disturbances in its function are related to a form of juvenile hypertension (AME), and how, through catalysis of corticosteroid metabolism, it mediates cell and tissue growth and maturation. We will use antibodies against the homogeneous 11 beta-dehydrogenase (11 beta DH) component generated in rabbits and pharmacological inhibitors of 11 beta DH, such as glycyrrhetinic acid, to test the hypothesis that the enzyme "protects" type I receptors against the mineralocorticoid activity of 11 beta- hydroxycorticosteroids by oxidizing the 11 beta-hydroxysteroids to the inactive 11-oxo forms. Studies will be performed in vitro in order to explore the molecular basis for the inhibition, and in vivo in order to develop an animal model of AME. We have determined that 11 beta DH is a glycoprotein. We will examine its glycoside structure, and the significance of the carbohydrate component for enzyme function. We will use monospecific polyclonal antibodies we have generated with homogeneous 11 beta DH to screen rat liver cDNA expression libraries incorporated into bacteriophage vectors. Our goal is to determine the nucleotide sequence of the mRNA derived from the structural gene and to deduce from this the primary amino acid sequence of 11 beta DH. We will isolate enzyme from human placenta and compare its properties with the clonally derived polypeptide and the enzyme of murine origin. The antibodies and cDNAs generated in our experiments will be used as histochemical probes to quantitate the distribution of 11 beta DH antigen and its associated mRNA within cells and tissues, and to monitor changes in enzyme level in response to hormonal intervention. We plan to purify corticosteroid 11-oxoreductase, the enzyme that catalyzes the reduction of cortisone to cortisol, and which cooperates with 11 beta DH in maintaining steroid homeostasis. Subsequent to purification, analytical studies similar to those planned for 11 beta DH will be performed. These investigations will help us understand a) how deficiency of 11 beta DH activity leads to hypertension; b) the physiological mechanism that control oxidation and reduction of corticosteroid at C-11.