Nucleic Acid Metabolism in Regenerating Rat Liver
Nucleic Acid Metabolism in Regenerating Rat Liver
复制标题
大鼠肝脏再生过程中的核酸代谢
DOI：
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发表时间：
1956
期刊：
影响因子：
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通讯作者：
V. Potter
中科院分区：
文献类型：
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作者：
L. Hecht;V. Potter
所述实验表明，在年轻生长的大鼠中，乳清酸-6-C14在初次注射后24小时内转化为DNA嘧啶，放射性在接下来的7周内保留在DNA中，在此期间肝脏重量增加约3倍。
部分肝切除术后40或46天的乳清酸-6-C14给药的年轻大鼠导致在5天或21天的肝再生期间的DNA的放射性含量基本上没有变化，在3/4只动物。这些数据支持DNA相对较高的生化稳定性的概念，并表明这在有丝分裂活性变化率很大的组织中是真实的。
在给予乳清酸-6-C14后，以足够短的间隔对生长或成年大鼠进行部分肝切除术时，放射性中间体被动员起来，该中间体作为合成标记DNA嘧啶核苷酸的前体池。在手术后的最初滞后期后，观察到DNA中C14含量增加。酸溶性部分和核RNA部分中的放射性水平在第一个13小时的间隔期间大幅下降，但在DNA合成期间，这些部分的C14含量保持不变。细胞质RNA组分中的总放射性足以解释酸溶性组分中放射性的维持，推测酸溶性组分为DNA和RNA的合成提供直接前体。
The experiments described demonstrated that in the young, growing rat orotic acid-6-C14 was converted to DNA pyrimidines for 24 hours following the initial injection, and the radioactivity was retained in the DNA during the next 7 weeks, a period during which the liver weight increased about threefold.
Partial hepatectomy 40 or 46 days after administration of orotic acid-6-C14 to the young rats resulted in essentially no change in the radioactivity content of the DNA during a 5- or 21-day period of liver regeneration in 3 out of 4 animals. These data support the proposed concept of the relatively high biochemical stability of DNA and show that this is true in tissues with widely varying rates of mitotic activity.
When partial hepatectomy was performed on growing or adult rats at sufficiently short intervals after administration of orotic acid-6-C14, a radioactive intermediate was mobilized which served as a precursor pool from which labeled DNA pyrimidine nucleotides were synthesized. After the initial lag period which followed the operation, an increase in the C14 content of the DNA was observed. The radioactivity level in the acid-soluble fraction and in the nuclear RNA fraction decreased extensively during the first 13-hour interval, but during the period of DNA synthesis the C14 content of these fractions remained constant. The total radioactivity in the cytoplasmic RNA fraction was more than adequate to account for the maintenance of the radioactivity in the acid-soluble fraction, which presumably provides the immediate precursors for the synthesis of DNA and RNA.