METABOLIC FLUX PATTERNS IN HEPATOMA AND HEPATOCYTES

这项建议的重点是能量代谢的两个准备工作， 细胞系（HTC细胞）和分离的肝细胞制备物。 的 调查将利用方程来量化的相对通量 碳通过TCA循环相关途径。 这些方程是由以下公式导出的： 私家侦探在开发新的TCA循环稳态模型的过程中， 碳同位素分布 这些方程的独特之处在于， 它们捕捉能量代谢模式的信息， 使用其他技术。 肝细胞和肝癌细胞之间的一个关键代谢区别是 利用谷氨酰胺作为肿瘤细胞的重要能量来源。 因此 肝癌代谢研究的主要目标是定量分析 谷氨酰胺代谢的模式。 在比较的模式， 肝癌和肝细胞的代谢，建模技术开发的 私家侦探将被用来考虑可能存在的超过 一个特定代谢物池。 关注肝细胞代谢的研究的主要目标是改善 碳同位素测定方法。 私家侦探 研究了常用校正因子的数学基础 同位素稀释的同位素稀释（“Hetenyi的因素”），并已 确定它可能会对糖异生产生误导性的估计， 一些实例。 因此，将开发一种新的方案来估计 比放射性的稀释，因为细胞外丙氨酸是 转化为草酰乙酸盐池，它是葡萄糖的前体。 本项目的长期目标是了解定量的作用 的因素，直接流入代谢物的生物合成或 氧化途径，并量化正常和 转化细胞

This proposal focuses on energy metabolism in two preparations, a hepatoma cell line (HTC cells), and an isolated hepatocyte preparation. The investigation will utilize equations to quantitate the relative flux of carbon through TCA cycle related pathways. These equations were derived by the P.I. in the process of developing a new steady state model of TCA cycle carbon isotope distribution. The unique feature of these equations is that they capture information about the pattern of energy metabolism not available using other techniques. A key metabolic distinction between hepatocytes and hepatoma cells is the use of glutamine as a significant energy source by tumor cells. Thus, the major goal of the hepatoma metabolic studies is a quantitative analysis of the pattern of glutamine metabolism. In comparing the pattern of metabolism in hepatoma and hepatocytes, modeling techniques developed by the P.I. will be used which consider the possible existence of more than one pool of specific metabolites. The major goal of studies focusing on hepatocyte metabolism is to improve the procedure for carbon isotopic measurement of gluconeogenesis. The P.I. has examined the mathematical basis of a commonly used correction factor for isotope dilution in gluconeogenesis ("Hetenyi's factor") and has determined that it may yield misleading estimates of gluconeogenesis in some instances. Thus, a new protocol will be developed to estimate the dilution in the specific radioactivity as extracellular alanine is converted to the oxaloacetate pool which is the precursor for glucose. The long term goals of this project are to understand the quantitative role of factors which direct the flux of metabolites into either biosynthetic or oxidative pathways and to quantify metabolic differences between normal and transformed cells.