The effect of dimethyl sulfoxide on the induction of DNA double-strand breaks in V79-4 mammalian cells by alpha particles
- MRC Radiobiology Unit, Didcot (United Kingdom); and others
The present study was undertaken to assess the protective effect of dimethyl sulfoxide (DMSO) against the induction and rejoining of DNA double-strand breaks (DSBs) and inactivation of V79-4 Chinese hamster cells by both high- and low-linear energy transfer (LET) radiations. The cells were exposed under aerobic conditions as monolayers to either low-LET photons ({sup 60}Co {gamma} rays) or high-LET {alpha} particles ({sup 238}Pu) at 277 K. The initial yield of DSBs, determined by elution under nondenaturing conditions, is linearly dependent on dose. When the irradiation was carried out in the presence of DMSO (0-0.6 mol dm{sup -3}), the initial yields of DSBs induced by both {gamma} and {alpha}-particle irradiation decrease. With {gamma} irradiation at [DMSO]>0.6 mol dm{sup -3}, a further decrease in the yield of DSBs by 50 {plus_minus} 5% and 32 {plus_minus} 4% for photons and {alpha}-particle irradiation with protection factors of 1.7 and 1.4, respectively, for survival and 2.0 and 1.5, respectively, for DSBs. After incubation of the irradiated cells for 3 h at 310K after high-LET irradiation, the residual yield of DSBs is reduced by <13% when the irradiations were carried out in the presence of 0.5 mol dm{sup -3} DMSO. With {gamma} irradiation in the presence of 0.5 mol dm{sup -3} DMSO, 90% of the DSBs are rejoined by 3 h incubation at 310 K. Therefore, the nonscavengeable DSBs induced by {alpha} particles are not significantly rejoined within 3 h, in contrast to rejoining of the majority of the nonscavengeable DSBs induced by {gamma} irradiation. From comparison of the data on DSBs and survival for {alpha}-particle irradiation, it is inferred that the severity of damage is reduced by DMSO through minimizing the formation of OH-induced sugar/base modifications in the vicinity of nonscavengeable DSBs. 47 refs., 5 figs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 160183
- Journal Information:
- Radiation Research, Vol. 144, Issue 1; Other Information: PBD: Oct 1995
- Country of Publication:
- United States
- Language:
- English
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