Tjernshaugen H, Gautvik K M
J Cell Physiol. 1976 May;88(1):13-22. doi: 10.1002/jcp.1040880103.
A nucleotidase of the combined 3'- and 5'-type (nucleotide phosphohydrolase, E.C.3.1.3.31) was present in the cytosol of regenerating rat liver cells, and of rat hepatoma and pituitary cells in culture. The enzyme activity per milligram of cell protein was very similar in regenerating liver and in three of the different cell types. The hepatoma cell strain which showed the slowest growth rate had a three-fold higher basal enzyme activity. After the first days of regenerative growth in rat liver and during early plateau phase of cell growth, there was a 50-120% increase in specific enzyme activity. In the hepatoma cells, the enzyme activities were also compared to the cellular content and synthesis of RNA and DNA. The increase in enzyme activity occurred concomitantly with a reduced incorporation of 3H-thymidine into DNA. The possible physiological role of this nucleotidase in nucleic acid and nucleotide metabolism is discussed.
一种兼具3'-和5'-型的核苷酸酶（核苷酸磷酸水解酶，E.C.3.1.3.31）存在于再生大鼠肝细胞、培养的大鼠肝癌细胞和垂体细胞的胞质溶胶中。每毫克细胞蛋白的酶活性在再生肝脏和三种不同细胞类型中非常相似。生长速度最慢的肝癌细胞系的基础酶活性高出三倍。在大鼠肝脏再生生长的最初几天以及细胞生长的早期稳定期，比酶活性增加了50 - 120%。在肝癌细胞中，还将酶活性与RNA和DNA的细胞含量及合成进行了比较。酶活性的增加与3H-胸腺嘧啶核苷掺入DNA的减少同时发生。本文讨论了这种核苷酸酶在核酸和核苷酸代谢中可能的生理作用。
