| Autor: |
L. A. Dethlefsen, Sosamma J. Berger, S. J. Petzold, C. S. Surowy, Nathan A. Berger, S. E. Sweiger |
| Rok vydání: |
1986 |
| Předmět: |
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| Zdroj: |
Radiation Research. 105:219 |
| ISSN: |
0033-7587 |
| Popis: |
Previous studies have shown that the well-oxygenated but nutrient-deprived quiescent (QI) cells of the 67 murine mammary carcinoma line are significantly more sensitive to radiation-induced cell killing than the well-oxygenated proliferating (P) cells. These QI cells also sustain more initial strand breaks per radiation dose and repair them more slowly than do P cells. We now report that NAD+ levels and rates of poly(ADP-ribosylation) show a trend similar in that both these metabolic parameters are lower in QI cells by a factor of two or more. NAD+ levels were measured in acid extracts of intact monolayers using an enzymatic cycling assay, while poly(ADP-ribosylation) was followed through the incorporation of radioactive NAD+ into polymer by permeabilized cells. The major proteins labeled by [32P]NAD+ were the same in P and QI cells. However, qualitative differences exist among minor poly(ADP-ribosylated) proteins, with some bands labeled in P cells but not detectably labeled in QI cells. These studies suggest similarities between the physiological state of QI cells and that of mature resting lymphocytes. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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