BIOCHEMICAL MECHANISMS OF CYCLOPHOSPHAMIDE TOXICITY

环磷酰胺毒性的生化机制

• 批准号: 3185769
• 负责人: HIRA L GURTOO
• 金额: $ 18.67万
• 依托单位: ROSWELL PARK CANCER INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-01-01 至 1989-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3185769
• 关键词: DNA; RNA; antioxidants; cyclophosphamide; cytochrome P450; drug adverse effect; drug interactions; drug metabolism; high performance liquid chromatography; liver disorder; macromolecule; neoplasm /cancer chemotherapy; neoplasm /cancer pharmacology; prostaglandin endoperoxide synthase; radiotracer; thin layer chromatography; tritium

The overall objectives of our studies on cyclophosphamide (CP) are to: (a) obtain a detailed understanding of the metabolism of CP and the interaction of CP metabolites with tissue macromolecules, especially DNA, RNA and proteins; (b) elucidate the chemical and biochemical basis of CP toxicity arising as a consequence of interaction between activated CP metabolites and tissue macromolecules; and (c) apply information derived in the above studies to develop biochemical interventions for obviating (ameliorating) some of the undesirable toxicities of CP with little interference of its chemotherapeutic activity. Metabolism of [3H-chloroethyl]-CP(3H-CP) and [14C-CP]-CP (14C-CP) to macromolecular-binding metabolites and to cytotoxic and other metabolites, formed by purified cytochrome P-450, hepatic nuclear fractions and prostaglandin synthetase, will be investigated in vitro. New metabolites, and metagolite-macromolecular adducts will be identified, isolated and characterized. In vivo formation of these adducts and their role in organ specific toxicities, especially liver and lung toxicity, of CP and its activated analogs (ASTZ-Z-7557 and PS-CP) will be investigated. Studies will be undertaken to define relationships between specific biochemical alterations (lipid peroxidation, glutathione depletion, inhibition of antioxidant defenses, DNA damage, and formation and persistance of CP metabolite - macromolecular adducts) induced by CP and certain specific toxicities of CP, such as liver and lung toxicity. Much of the proposed work will be performed: (a) in vitro with 14C-CP, 3H-CP and some labeled metabolites of CP (e.g. 4-hydroxy-CP, didechlorodihydroxy-CP, phosphoramide mustard), nucleic acids (DNA, RNA, purine and pyrimidine-nucleoside polymers) and enzyme preparations (cytochromes P-450, prostaglandin synthetase and hepatic nuclei) from rats and mice; (b) in vivo with labeled-CP in mice and rats to determine the in vivo macromolecular binding of CP and its relation to toxicity; and (c) in vivo in rats and mice to elucidate the mechanism by which CP produces specific biochemical effects, e.g. glutathione depletion and lipid peroxidation. Particular methods to be used include: radiochemical techniques, thin layer chromatography, high pressure liquid chromatography, column chromatography, organic analytical techniques, and other chemical, biochemical and enzymological methods.

我们对环磷酰胺 (CP) 研究的总体目标是：(a) 详细了解 CP 的代谢及其相互作用 CP代谢物与组织大分子，特别是DNA、RNA和 蛋白质； (b) 阐明CP毒性的化学和生化基础 由于活化的 CP 代谢物之间相互作用而产生 和组织大分子； (c) 应用上述得出的信息 研究开发生化干预措施来避免（改善） CP 的一些不良毒性对其影响很小 化疗活性。 [3H-氯乙基]-CP(3H-CP)和的代谢 [14C-CP]-CP (14C-CP) 与大分子结合代谢物和细胞毒性 和其他代谢物，由纯化的细胞色素 P-450、肝核形成 级分和前列腺素合成酶，将在体外进行研究。 新的 将鉴定代谢物和代谢物-大分子加合物， 分离并表征。 这些加合物的体内形成及其 器官特异性毒性，特别是肝和肺毒性中的作用 将研究 CP 及其激活类似物（ASTZ-Z-7557 和 PS-CP）。 将进行研究以确定具体之间的关系 生化改变（脂质过氧化、谷胱甘肽消耗、 抑制抗氧化防御、DNA 损伤和形成 CP 代谢物（大分子加合物）的持久性由 CP 诱导 CP 的某些特定毒性，例如肝毒性和肺毒性。 大部分拟议工作将在以下方面进行：(a) 在体外使用 14C-CP， 3H-CP 和 CP 的一些标记代谢物（例如 4-羟基-CP、 二脱氯二羟基-CP、磷酰胺芥末）、核酸（DNA、RNA、 嘌呤和嘧啶核苷聚合物）和酶制剂 （细胞色素 P-450、前列腺素合成酶和肝细胞核）来自大鼠 和老鼠； (b) 在小鼠和大鼠体内用标记-CP 测定 CP的体内大分子结合及其与毒性的关系； (c) 在 在大鼠和小鼠体内阐明 CP 产生的机制 特定的生化效应，例如谷胱甘肽消耗和脂质 过氧化。 使用的具体方法包括：放射化学 技术，薄层色谱法，高压液相色谱法， 柱色谱、有机分析技术和其他化学、 生化和酶学方法。