DNA-SYNTHESIS AND RELATED ENZYMES ALTERED IN COMPENSATORY LUNG GROWTH IN RATS
DNA-SYNTHESIS AND RELATED ENZYMES ALTERED IN COMPENSATORY LUNG GROWTH IN RATS
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DOI：
10.3109/00365519209115516
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发表时间：
1992-11-01
影响因子：
2.1
通讯作者：
KIDA, K
中科院分区：
文献类型：
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作者：
KUBOI, S;MIZUUCHI, A;KIDA, K
对4周龄雄性Fischer-344大鼠进行左肺切除术。本文观察了55只肺切除大鼠对侧肺DNA合成及相关酶活性的变化，并与假手术组（55只）和未处理对照组（40只）作了比较。在第1天和第7天，再生肺的胸苷激酶和DNA聚合酶活性升高。为了确定DNA聚合酶在粗提物中的分子形式，进行磷酸纤维素柱层析。在第1、3和7天再生肺中具有最高活性的DNA聚合酶类型为α。这些结果表明，在肺切除术后的剩余肺中，用于细胞增殖的DNA复制升高。此外，在其余肺中观察到DNA生物合成的叶间差异。在第7天，心叶中的增加尤其明显，随后其余叶的DNA含量增加。从这些观察结果中，我们得出结论：（1）DNA聚合酶α活性的增加可能是代偿性肺生长的初始变化，可能是由肺组织中某些未知的刺激物引起的;（2）至少在肺切除术后3天内，肺叶之间的DNA生物合成可能不同。
Left pneumonectomy was performed on 4 week-old male Fischer-344 rats. Changes in DNA biosynthesis and the activities of related enzymes were studied in the contralateral lungs of the pneumonectomized animals (n=55) and compared with sham-operated (n=55) and untreated control animals (n=40)The wet weight of the contralateral lung of the pneumonectomized rats reached that of both lungs of the untreated and sham-operated rats 14 days after the operation. The activities of thymidine kinase and DNA polymerase from the regenerating lungs were elevated on Days 1 and 7. To determine the molecular forms of DNA polymerase in the crude extract, phosphocullulose column chromatography was performed. The type of DNA polymerase with the highest activity was alpha in regenerating lung on Days 1, 3, and 7. These results suggest that DNA replication for cellular proliferation was elevated in the remaining lung after pneumonectomy. In addition, an interlobar difference in DNA biosynthesis was observed in the remaining lung. The increase was especially marked in the cardiac lobe, followed by increases in the DNA content of the remaining lobes on Day 7. From these observations we conclude (1) that increased activity of DNA polymerase alpha is likely to be an initial change in compensatory lung growth, and may be caused by some unknown stimulator in lung tissue, and (2) that DNA biosynthesis may differ among the lobes of the lung, at least until 3 days post-pneumonectomy.