Strong J M, Anderson L W, Monks A, Chisena C A, Cysyk R L
Anal Biochem. 1983 Jul 15;132(2):243-53. doi: 10.1016/0003-2697(83)90003-9.
Gas chromatographic/mass spectrometric methods for the measurement of the flux through the de novo pyrimidine biosynthetic pathway by quantitating the incorporation of [13C]bicarbonate and 13CO2 into the uracil nucleotide pool in L1210 tumors are reported. Simultaneous measurements of the incorporation of [13C]bicarbonate and the more commonly used [14C]bicarbonate into uridine of L1210 cells in vitro showed that the two methods were comparable. A modification of the method was applied to in vivo studies where the incorporation of 13CO2 into the uracil nucleotide pool of L1210 tumors in mice was quantitated. The measurements were used to determine changes in the flux through the de novo pyrimidine pathway in animals pretreated with known inhibitors of the pathway. A comparison of control animals with those pretreated with 6-azauridine, acivicin, and pyrazofurin resulted in mean percentage inhibitions of 87, 95, and 94%, respectively. This technique should allow investigation of the respective contributions of salvage and de novo synthesis in the formation of pyrimidines in vivo and the effects of agents designed as enzyme inhibitors of the de novo pathway.
报道了通过定量[13C]碳酸氢盐和13CO2掺入L1210肿瘤尿嘧啶核苷酸库来测量从头嘧啶生物合成途径通量的气相色谱/质谱方法。体外同时测量[13C]碳酸氢盐和更常用的[14C]碳酸氢盐掺入L1210细胞尿苷的情况，结果表明这两种方法具有可比性。该方法的一种改进应用于体内研究，其中定量了13CO2掺入小鼠L1210肿瘤尿嘧啶核苷酸库的情况。这些测量用于确定用该途径已知抑制剂预处理的动物中从头嘧啶途径通量的变化。将对照动物与用6-氮杂尿苷、阿西维辛和吡唑呋林预处理的动物进行比较，平均抑制率分别为87%、95%和94%。该技术应有助于研究体内嘧啶形成中补救合成和从头合成的各自贡献以及作为从头途径酶抑制剂设计的药物的作用。
