Wan C W, Mak T W
Cancer Res. 1978 Sep;38(9):2768-72.
Previous work has suggested that 1-beta-D-arabinofuranosylcytosine 5'-triphosphate is the active metabolite of 1-beta-D-arabinofuranosylcytosine. The amount of 1-beta-D-arabinofuranosylcytosine 5'-triphosphate formed in tissues has been shown to be influenced by the relative levels of deoxycytidine kinase and cytosine deaminase. In this study we have measured the intracellular levels of deoxycytidine kinase and cytosine deaminase activities in synchronized cultures of normal rat kidney cells. The deoxycytidine kinase activity was found to be cell cycle related with a minor peak of activity in early G1 phase and a major peak of activity in middle and late S phase. The cytosine deaminase activity was also found to be cycle dependent with a peak of activity at G1 phase and another at S phase of the cell cycle. Similar results were obtained when cytosine deaminase activities were measured with cytidine, deoxycytidine, or 1-beta-D-arabinofuranosylcytosine as substrate. Present studies also confirmed earlier studies by other workers that the main effect of 1-beta-D-arabinofuranosylcytosine is in the late S phase of the cell cycle.
先前的研究表明，1-β-D-阿拉伯呋喃糖基胞嘧啶5'-三磷酸是1-β-D-阿拉伯呋喃糖基胞嘧啶的活性代谢产物。组织中形成的1-β-D-阿拉伯呋喃糖基胞嘧啶5'-三磷酸的量已被证明受脱氧胞苷激酶和胞嘧啶脱氨酶相对水平的影响。在本研究中，我们测定了正常大鼠肾细胞同步培养物中脱氧胞苷激酶和胞嘧啶脱氨酶活性的细胞内水平。发现脱氧胞苷激酶活性与细胞周期相关，在G1期早期有一个较小的活性峰值，在S期中期和后期有一个较大的活性峰值。还发现胞嘧啶脱氨酶活性也与细胞周期有关，在细胞周期的G1期和S期各有一个活性峰值。当以胞苷、脱氧胞苷或1-β-D-阿拉伯呋喃糖基胞嘧啶为底物测量胞嘧啶脱氨酶活性时，得到了类似的结果。目前的研究也证实了其他研究人员早期的研究结果，即1-β-D-阿拉伯呋喃糖基胞嘧啶的主要作用在细胞周期的S期后期。
