Ornithine decarboxylase activity and DNA synthesis in Morris hepatomas 5123-C and 7800.
Ornithine decarboxylase activity and DNA synthesis in Morris hepatomas 5123-C and 7800.
复制标题
Morris 肝癌 5123-C 和 7800 中鸟氨酸脱羧酶活性和 DNA 合成。
DOI：
10.1016/0024-3205(76)90271-x
复制
发表时间：
1976
期刊：
影响因子：
6.1
通讯作者：
V. Potter
中科院分区：
文献类型：
--
作者：
M. Pariza;S. Yanagi;J. A. Gurr;D. E. Bushnell;H. Morris;V. Potter
The activities of ornithine decarboxylase (ODC) and thymidine kinase (TK) and the rates of DNA synthesis were determined in hepatomas and livers of rats bearing Morris hepatoma 5123-C or 7800 and entrained to a schedule of 12 hours of light followed by 12 hours of darkness, with food (60% protein) available only during the first 2 hours of the dark period. ODC activity in hepatoma 5123-C displayed a diurnal oscillation, increasing 2-fold during the feeding period and then rapidly decaying to 20% of the peak level. The livers of rats bearing hepatoma 5123-C exhibited a similar oscillation of ODC activity, with peak values lower than in the hepatomas but higher than in the livers of control (non-tumor bearing) animals. TK activity and the rate of DNA synthesis in hepatoma 5123-C were low during most of the dark period but increased rapidly towards the end of the dark period. DNA synthesis reached a plateau at the dark-light interface and then rapidly declined, but TK activity remained high during the light period. Similar studies on hepatoma 7800 established that ODC activity in this hepatoma did not oscillate but remained at low levels throughout the day. Similarly, host livers of rats bearing hepatoma 7800 did not exhibit the diurnal oscillation of ODC activity characteristic of liver from control rats, but showed a slow increase in activity followed by a plateau and a slow decline to base-line levels. DNA synthesis in hepatoma 7800 was constant throughout the day, whereas TK activity may have increased during the dark period. In the livers of control rats and animals bearing hepatoma 5123-C or 7800, TK activity and rate of DNA synthesis were at low levels at all times studied and appeared not to oscillate.
