Abstract
Two strains of murine lymphoma cells, L5178Y-R (LY-R) and L5178Y-S (LY-S) differ in radiosensitivity (D0 ca 1.0 and 0.5 Gy) In this cellular system we tested the influence of poly (adenosine diphosphoribose) transferase (ADPRT) inhibitors, benzamide and caffeine, in combination with X or gamma irradiation under aerobic conditions, on the cellular response. We found a small difference between LY-R and LY-S cell strains in incorporation of 3H from [3H]-NAD (nicotinamide dinucleotide) into permeabilized cells. The incorporation was related to DNA degradation initiated by the permeabilization procedure. The post-irradiation inhibition of DNA synthesis was reversed only in LY-S cells by 2mM benzamide or 2mM caffeine treatment. Changes in the cell cycle, as determined by flow-cytometry, were of similar character in both LY-R and LY-S cells, within 12 h after irradiation, whereas the effect of treatment on survival differed: only LY-S cells were radiosensitized by benzamide; both LY strains were sensitized by caffeine, but to different extents. From these observations it followed that there was a pattern of relations between the extent of postirradiation DNA synthesis, duration of mitotic delay and recovery.
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Selected References
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- Berger N. A., Weber G., Kaichi A. S. Characterization and comparison of poly(adenosine dephosphoribose) synthesis and DNA synthesis in nucleotide-permeable cells. Biochim Biophys Acta. 1978 Jun 22;519(1):87–104. doi: 10.1016/0005-2787(78)90064-3. [DOI] [PubMed] [Google Scholar]
- Purnell M. R., Whish W. J. Novel inhibitors of poly(ADP-ribose) synthetase. Biochem J. 1980 Mar 1;185(3):775–777. doi: 10.1042/bj1850775. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rydberg B. The rate of strand separation in alkali of DNA of irradiated mammalian cells. Radiat Res. 1975 Feb;61(2):274–287. [PubMed] [Google Scholar]
- Szumiel I. Ca2+, Mg2+ and (adenosine diphosphate ribose)n in cellular response to irradiation. J Theor Biol. 1983 Apr 7;101(3):441–451. doi: 10.1016/0022-5193(83)90149-2. [DOI] [PubMed] [Google Scholar]