CARDIOVASCULAR CA ANTAGONIST RECEPTORS

心血管 CA 拮抗剂受体

• 批准号: 3486236
• 负责人: ARNOLD SCHWARTZ
• 金额: $ 23.41万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3486236
• 关键词: Xenopus; azepines; calcium binding protein; calcium channel; calcium channel blockers; cardiovascular disorder; cerebrovascular disorders; complementary DNA; coronary disorder; diltiazem; drug receptors; gene expression; genetic regulation; heart pharmacology; hormone regulation /control mechanism; hypertension; myocardium; oogenesis; pharmacogenetics; phenylalkylamine; protein structure function; striated muscles; vascular smooth muscle; verapamil

The primary focus of this project is to elucidate the structure and function of the receptor for three classes of calcium channel inhibitor drugs, viz., DIHYDROPYRIDINES, (e.g., nifedipine), PHENYLALKYLAMINES (e.g., verapamil), and BENZOTHIAZEPINES (e.g., diltiazem) in heart, vascular smooth muscle and brain. These drugs are used to treat coronary artery disease and hypertension and may be valuable in related conditions such as cerebral vasospasm. The drug binding sites are located in specific domains of a large protein, the alpha 1 subunit of the L type voltage-dependent calcium channel (VDCC). The central hypothesis is that tissue-specific alpha 1 isoforms contain the drug binding domains and form the calcium channel. Other subunits, however, may be required for function and regulation. The three specific aims are: (1) to isolate and sequence full-length alpha 1 cDNA clones from heart, vascular smooth muscle and brain; (2) to express VDCC activity with appropriate pharmacology using alpha 1 cDNA clones alone or in combination with cDNA clones encoding the other VDCC subunits; (3) to identify the drug binding domains and the sites for regulation of VDCC within the alpha 1 subunit. Skeletal muscle alpha 1 cDNAs have been isolated and sequenced (skeletal muscle T-tubules are the richest source of VDCC and calcium antagonist binding sites) and will be used to identify alpha 1 isoforms in other tissues. The alpha 1 subunit alone or in combination with other subunits will be expressed in Xenopus oocytes and/or mammalian cells. Function of the expressed protein(s) will be examined using radioligand binding and electrophysiological techniques. Based upon deduced primary amino acid sequence of the alpha 1 isoforms and the known tissue-specific pharmacological characteristics, chimeric constructs and selected mutants will be made, expressed and functionally evaluated for VDCC activity and pharmacology. These proposed studies are relevant to understanding the nature of the receptors for, and hence, bear on the mechanism of the calcium antagonists. Further, if VDCC are altered in certain cardiovascular disorders as has been suggested by published studies, the nature of the putative defects can be explored by genetic means. The data derived from the proposed experiments should be useful in understanding the function and regulation of the receptor and of channel activity.

该项目的主要重点是阐明结构和 三类钙通道抑制剂受体的功能 药物，即，二氢吡啶类，（例如，硝苯地平）， (e.g.,维拉帕米），和苯并硫氮平类（例如，地尔硫卓）， 血管平滑肌和大脑。 这些药物用于治疗冠心病 动脉疾病和高血压，并可能在相关条件下有价值 如脑血管痉挛。 药物结合位点位于 大蛋白质的特定区域，即L型的α 1亚基 电压依赖性钙通道（VDCC）。 核心假设是， 组织特异性α 1同种型含有药物结合结构域， 形成钙通道。 然而，可能需要其他子单位， 功能和调节。 三个具体目标是：（1）隔离 和序列全长α 1 cDNA克隆从心脏，血管平滑肌， 肌肉和大脑;（2）表达VDCC活性与适当的 单独使用α 1 cDNA克隆或与cDNA组合使用的药理学 编码其他VDCC亚基的克隆;（3）鉴定药物结合 结构域和α 1亚基内的VDCC调节位点。 骨骼肌α 1 cDNA已被分离和测序（骨骼肌 肌T小管是VDCC和钙拮抗剂最丰富的来源 结合位点），并将用于鉴定其他细胞中的α 1同种型。 组织中 α 1亚基单独或与其他亚基结合 将在非洲爪蟾卵母细胞和/或哺乳动物细胞中表达。 功能 使用放射性配体结合检测表达的蛋白质， 电生理技术。 基于推导的一级氨基酸 α 1亚型和已知的组织特异性 药理学特征、嵌合构建体和选择的突变体 将进行VDCC活性的制备、表达和功能评价， 药理学 这些拟议的研究与理解 受体的性质，因此，承担的机制， 钙拮抗剂 此外，如果VDCC在某些情况下发生变化， 已发表的研究表明， 可以通过遗传学方法来探索推定缺陷的性质。 的 从拟议的实验中得出的数据应该是有用的， 了解受体和通道的功能和调节 活动