Zakharov A F, Baĭramian T L
Tsitologiia. 1978 Nov;20(11):1249-55.
The incorporation of 3H-deoxycytidine (3H-Cdr) in the presence of thymidine (Tdr) into cultured human blood lymphocytes has been studied. The analysis of the label in interphase nuclei as well as in chromosomes at metaphase was carried out. The labeling was much higher when 3H-Cdr (0.5 to 1.0 C/ml, 2--4 x 10(-5) mM) was added to the cultures simultaneously with Tdr (4 x 10(-1) mM). This observation is considered as an indication that in the presence of high doses of Tdr exogeneous Cdr is utilized to synthesize cytosine of DNA rather than thymidine. During the first hours after its addition, the bulk of 3H-Cdr is eliminated from the culture medium. At 12 hrs of the incubation, the medium seems to be free of the nucleoside as shown particularly from the single chromatid localization of the label in chromosomes of the second mitosis. The incorporation into lymphocytes of 3H-Tdr administered in the same dose under the same conditions was registered for the whole period of observation (24 hrs). The data obtained are discussed in relation to lymphocyte catabolism of exogeneous nucleosides.
已对在胸苷（Tdr）存在下将3H-脱氧胞苷（3H-Cdr）掺入培养的人血淋巴细胞进行了研究。对间期核以及中期染色体中的标记物进行了分析。当将3H-Cdr（0.5至1.0居里/毫升，2 - 4×10^(-5)毫摩尔）与Tdr（4×10^(-1)毫摩尔）同时添加到培养物中时，标记率要高得多。这一观察结果被认为表明在高剂量Tdr存在下，外源Cdr被用于合成DNA的胞嘧啶而非胸苷。在添加3H-Cdr后的最初几个小时内，大部分3H-Cdr从培养基中被清除。在培养12小时时，培养基似乎已不含该核苷，这尤其从第二次有丝分裂染色体中标记物的单染色单体定位可以看出。在相同条件下以相同剂量施用的3H-Tdr在整个观察期（24小时）内都被记录到掺入淋巴细胞中。所获得的数据结合外源核苷的淋巴细胞分解代谢进行了讨论。
