NMR OF FBP PROTECTION IN HYPOXIC RAT BRAIN SLICES

缺氧大鼠脑切片中 FBP 保护的 NMR

• 批准号: 6489996
• 负责人: Lawrence Litt
• 金额: $ 31.62万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-07-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6489996
• 关键词: Krebs' cycle; NMDA receptors; adenosine triphosphate; bioimaging /biomedical imaging; brain injury; brain metabolism; cellular respiration; cerebral ischemia /hypoxia; enzyme activity; enzyme inhibitors; fructose phosphate; gene expression; glucose metabolism; heat shock proteins; immunocytochemistry; laboratory rat; messenger RNA; neuroprotectants; neurotoxins; nitric oxide synthase; nuclear magnetic resonance spectroscopy; pentose phosphate; pentosyltransferase; protooncogene; tissue /cell culture

It has been known for years that pre- and post-treatment with fructose-1,6-bisphosphate (FBP) can dramatically improve hypoxic/ ischemic tolerance in vivo in brain, muscle, and intestinal tissues, suggesting huge potential benefits in high risk childbirth, surgeries where there is major blood flow interruption or total circulatory arrest, and organ transplantation. Primary mechanisms of FBP protection affect intracellular metabolism, which is now easier to explore because of advances in high resolution nuclear magnetic resonance (NMR) spectroscopy. The Specific Aims of 14.1 Tesla ex vivo and in vitro multinuclear NMR spectroscopy studies of neonatal rat brain slices are to determine: 1) if [1-13C]fructose-1,6-bisphosphate enters oxygenated and/or hypoxic cells, and if so, its metabolic fate and influence. 2) if FBP-induces metabolic changes in the intracellular metabolism of glucose, particularly during oxygen deprivation. [U-13C]glucose will be used to distinguish glial from neuronal TCA cycle activity. [2-13C]glucose will probe the activity of the pentose phosphate pathway (PPP). [1-13C]glucose will be used to determine total glucose utilization. 3) if FBP preservation of ATP is secondary to its prevention of glutamate toxicity and/or its prevention of damage from PARS (polyadenosine 5'-diphosphoribose synthetase, also know as PARP.) During hypoxia FBP increases glucose metabolism by the PPP, a source of ribose. Hypoxia studies will be performed with nontoxic glutamate receptor blockade and nontoxic inhibition of glutamata release, and with inhibitors of PARS. 4) if hypoxia-induced changes in ATP are associated with concomitant changes in the apparent diffusion coefficient of brain slice water, ADCw, which is commonly used clinically; increases in brain slice water; histological measures of cell swelling; and immunohistological measures of cell and mitochondrial injury. The hypotheses tested are that: 1) FBP enters cells more readily during hypoxia and serves as a metabolic modulator and substrate; 2) Because of PARS, ATP maintenance by FBP during hypoxia requires increased glucose metabolism by the PPP; 3) apparent intracellular diffusion coefficients can be used to accurately estimate cell swelling and the integrity of intracellular metabolism; and 4) when FBP sustains ATP levels during hypoxia, mitochondrial viability is also sustained.

多年来，人们已经知道， 果糖-1，6-二磷酸（FBP）可显著改善缺氧/缺血 在脑、肌肉和肠组织中的体内耐受性，表明巨大的 高风险分娩的潜在益处， 血流中断或完全循环停止以及器官移植。 FBP保护的主要机制影响细胞内代谢， 由于高分辨率核磁共振技术的进步， 共振（NMR）光谱。14.1特斯拉体外和体内的具体目标 新生大鼠脑切片的体外多核NMR光谱研究是为了 确定：1）[1- 13 C] 1，6-二磷酸果糖是否进入氧化状态和/或 缺氧细胞，如果是这样，它的代谢命运和影响。2)如果FBP诱导 细胞内葡萄糖代谢的代谢变化，特别是 在缺氧状态下[U-13 C]葡萄糖将用于区分神经胶质细胞 来自神经元TCA循环活动。[2- 13 C]葡萄糖将探测 戊糖磷酸途径（PPP）。[1- 13 C]葡萄糖将用于测定总 葡萄糖利用率3)如果FBP对ATP的保存是次要的， 防止谷氨酸毒性和/或防止PARS损伤 （聚腺苷5 '-二磷酸核糖合成酶，也称为PARP。）期间 缺氧FBP通过PPP（核糖的来源）增加葡萄糖代谢。 缺氧研究将使用无毒谷氨酸受体阻断剂进行， 谷氨酸释放的无毒抑制，以及PARS抑制剂。4)如果 缺氧诱导的ATP变化与伴随的 脑切片水的表观扩散系数，ADCw，通常为 临床使用;脑片含水量增加;细胞的组织学测量 肿胀;以及细胞和线粒体损伤的免疫组织学测量。的 检验的假设是：1）在缺氧期间，FBP更容易进入细胞， 作为代谢调节剂和底物; 2）由于PARS，ATP 在缺氧期间由FBP维持需要通过 PPP; 3）表观细胞内扩散系数可用于准确测定 估计细胞肿胀和细胞内代谢的完整性;以及4） 当FBP在缺氧期间维持ATP水平时， 反对有效