COLLABORATIVE PROJECTS IN ENVIRONMENTAL HEALTH SCIENCES

工作总结：本项目包括 质谱仪和质谱仪合作的努力 与研究所内外的其他团体合作， 共同关心的问题。这些项目的主要重点 是：1）未知化合物的结构测定; 2） 生物途径的识别和/或确认; 3） 定量;和4）发展战略的结构 生物重要化合物的测定。当前重大 正在进行的合作项目包括：1）量化 细胞中的羟基十八碳二烯酸和羟基二十烷酸; 2)花生四烯酸代谢物的定量（D. Zeldin，LPP）。 花生四烯酸蛋氨酸的定量-最灵敏的 和准确的方法定量类二十烷酸 生理样品是通过选择离子监测（SIM）， 负离子化学电离（NICI）质谱。我们 目前定量类二十烷酸代谢物作为几种 问题研究这些包括：花生四烯酸的表征 一种新的细胞色素P450代谢产物，CYP 2 J5，从一个 小鼠肝脏cDNA文库的构建及其在肾小管内的表达 肾皮质的一部分CYP 2 J5花生四烯酸氧化产物 被认为在肾脏中发挥重要的功能作用。 测定花生四烯酸代谢的变化， 禁食期间发生的P450功能变化的功能， 在大鼠中重新喂养。 花生四烯酸代谢产物的表征 在鱼类中作为内源性 花生四烯酸代谢作为一个功能的挑战， TCDD和BP。 CYP 2 J亚家族的表征 细胞色素P450的含量 15-lo高表达 在人类结肠直肠肿瘤中。15-lo表达的功能是 在Caco-2细胞中进行研究。15-lo在Na 丁酸诱导细胞凋亡和分化。抑制 15-lo增强NaBT诱导的细胞凋亡。代谢研究 使用细胞裂解物表明AA的外源性代谢的转变 15-HETE和13-HODE。的时间过程 在细胞诱导过程中形成15-HETE和13-HODE 分化和凋亡被确定为一种手段， 确定这些细胞中15-LO表达的功能。

Summary of Work: This project includes those endeavors in which the mass spectrometry workgroup collaborates with other groups, both inside and outside the Institute to solve problems of mutual interest. The major focuses of these projects are: 1) structure determination of unknown compounds; 2) identification and/or confirmation of biological pathways; 3) quantitation; and 4) development of strategies for the structure determination of biologically important compounds. Current major collaborative projects under way include: 1)quantitation of hydroxyoctadecadienoic acid and hydroxyeicosanoic acids in cells; 2) quantitation of arachidonic acid metabolites (D. Zeldin, LPP). Quantitation of Arachidonic Acid Metabolites - The most sensitive and accurate method for quantitation of eicosanoids in physiological samples is by selected ion monitoring (SIM) under negative ion chemical ionization (NICI) mass spectrometry. We are currently quantifying eicosanoid metabolites as part of several studies. These include: Characterization of the arachidonic acid metabolites of a new cytochrome P450, CYP2J5, isolated from a mouse liver cDNA library and abudantly expressed within tubules of the renal cortex. CYP2J5 arachidonic acid oxidation products are postulated to play important functional roles in the kidney. Determination of the variations in arachidonic acid metabollism as a function of changes in P450 function occurring during fasting and refeeding in rats. Characterization of arachidonic acid metabolites in fish as characterization of the alteration of endogenous arachidonic acid metabolism as a function of being challenged with TCDD and BP. Characterization of the CYP2J subfamily cytochrome P450s in the human jejunum. 15-lo is highly expressed in human colorectal tumors. The function of 15-lo expression is being investigated in caco-2 cells. The 15-lo is expressed during Na butyrate induced apoptosis and cell differentiation. Inhibition of 15-lo enhances the NaBT induced apoptosis. Metabolism studies using cell lysates indicate a shift in exogenous metabolism of AA and LA to 15-HETE and 13-HODE. The time course for the formation of 15-HETE and 13-HODE during the induction of cell differentiation and apoptosis is being determined as a means of determining the function of 15-lo expression in these cells.