GLUTATHIONE INTERACTIONS IN CHEMICAL EMBRYOTOXICITY

谷胱甘肽在化学胚胎毒性中的相互作用

• 批准号: 3465318
• 负责人: CRAIG HARRIS
• 金额: $ 11.35万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-01-01 至 1994-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3465318
• 关键词: acetaminophen; acetylaminofluorene; adduct; aminoacid biosynthesis; biotransformation; chemotherapy; cysteine; detoxification; early embryonic stage; embryo /fetus culture; embryo /fetus drug adverse effect; embryo /fetus toxicology; environmental toxicology; enzyme mechanism; glutathione; glycolysis; high performance liquid chromatography; laboratory rat; nitroso compounds; physical chemical interaction; prenatal growth disorder; scintillation counter; spectrometry; sulfur aminoacid; teratogens; thiols; toxin metabolism; valproate; vitelline membrane

A major goal of this research proposal will be to evaluate the status of glutathione (GSH) and related low molecular weight thiols (LMWT) and their interactions with known embryotoxins/teratogens of environmental and therapeutic importance. The developing rat, during the teratogen and embryotoxin-sensitive stage of early organogenesis (gestational days 9-11), will be studied using the whole embryo culture system in order to allow for experimental accessibility to the intact conceptus and to eliminate confounding maternal hormonal and physiological influences. This evaluation will involve an analysis of routes of GSH (or precursor) entry into the conceptus, consequences of decreased precursor availability (i.e. nutritional factors), determination of alternative GSH synthetic capacities in the visceral yolk sac (VYS) and embryo proper, and overall GSH turnover under normal and stress conditions. Alterations in the different chemical forms of GSH and related LMWT will be evaluated using HPLC techniques, with special attention given to the quantitation and distribution of GSH and cysteine and their protein-and mixed-disulfide forms. Chemical modulation of GSH levels (BSO, menadione, diamide, OTC, etc.) will be aimed at producing different conditions of depletion and oxidative state and will be compared to changes which occur following the addition of the model teratogens/embryotoxins (2-nitrosofluorene, 7-OH-acetylaminofluorene, acetaminophen, and valproic acid). The chosen compounds represent known in vitro dysmorphogens which differ with respect to metabolism, potential interactions with GSH (adduct formation will be measured) and the overlapping spectrum of abnormalities each produce. Specific changes in intracellular GSH and LMWT status in the embryo and VYS will be correlated with the morphological abnormalities produced by each compound in vitro to determine whether a particular defect may be related to a common qualitative or quantitative shift in thiol status. Decreased conceptual detoxication capacity due to changes in intracellular GSH/LMWT content or redox state may promote increased embryotoxicity/dysmorphogenesis due to unchecked, production of reactive intermediates and their direct interaction with cellular targets. The final goal of this proposal, however, will be to evaluate the possibility that changes in intracellular GSH/LMWT status induced through environmental (nutritional or physiological) factors, chemical modulation or through detoxication of model, embryotoxins/teratogens are independently sufficient to alter any of several critical metabolic or physiologic processes believed to be regulated by GSH and related LMWT. Effects on glycolysis, NADPH/NADP+ status, pentose phosphate shunt activity, lysosomal proteolysis (histotrophic nutrition) and utilization of GSH-derived cysteine in cysteamine, taurine and CoA biosynthesis will be evaluated. Successful completion of this project should provide valuable information concerning the interaction of environmental and therapeutic agents with embryonic GSH- based detoxication systems and suggest possible points of regulatory impact in altering reproductive outcome.

该研究建议的主要目标是评估 谷胱甘肽（GSH）和相关的低分子量硫醇（LMWT）及其 与已知的胚胎毒素/环境和环境的畸胎组的相互作用 治疗重要性。 发育中的大鼠，在畸胎上和 早期器官发生的胚胎敏感阶段（妊娠第9-11天）， 将使用整个胚胎培养系统研究 对完整概念的实验可访问性并消除 混淆母体荷尔蒙和生理影响。 这 评估将涉及对GSH（或前体）条目的途径的分析 在概念中，前体可用性降低的后果（即 营养因素），确定替代GSH合成能力 在内脏的蛋黄囊（VYS）和胚胎中适当，总体GSH周转率 在正常和应力条件下。 不同化学品的改变 将使用HPLC技术评估GSH和相关LMWT的形式 特别注意GSH和GSH的分布 半胱氨酸及其蛋白质和混合硫化物形式。 化学调制 GSH级别（BSO，Menadione，Diamide，OTC等）将针对 产生耗尽和氧化状态的不同条件，将是 与添加模型后发生的变化相比 催化剂/胚胎毒素（2-硝基氟烯，7-OH-乙酰氨基氟氟烯烯， 对乙酰氨基酚和丙戊酸）。 所选化合物表示已知 在代谢方面有所不同的体外畸形症 与GSH的相互作用（将测量加合物形成）和 异常的重叠频谱每种产生。 具体更改 胚胎和VY中的细胞内GSH和LMWT状态将相关 每种化合物在体外产生的形态异常 确定特定缺陷是否可能与常见 硫醇状况的定性或定量转移。 减少概念 由于细胞内GSH/LMWT含量的变化或 氧化还原状态可能会促进由于 未经检查的是，反应性中间体的产生及其直接 与细胞靶标相互作用。 该提议的最终目标， 但是，将评估细胞内变化的可能性 通过环境诱导的GSH/LMWT状态（营养或 生理因素，化学调节或通过解毒 模型，胚胎毒素/致毒素是独立的，足以改变任何 被认为是几个关键的代谢或生理过程 由GSH和相关LMWT调节。 对糖酵解，NADPH/NADP+的影响 状态，戊糖磷酸分流活性，溶酶体蛋白水解 （组织营养）和GSH衍生的半胱氨酸的利用 将评估氰氨酸，牛磺酸和COA生物合成。 成功的 该项目的完成应提供有关的宝贵信息 环境和治疗剂与胚胎GSH-的相互作用 基于解毒系统，并提出调节影响的可能点 改变生殖结果。