Study of Dose-rate and Split-dose Effects on thein VitroMicronucleus Yield in Human Lymphocytes Exposed to X-rays
- 1 January 1992
- journal article
- Published by Taylor & Francis in International Journal of Radiation Biology
- Vol. 61 (6) , 777-784
- https://doi.org/10.1080/09553009214551641
Abstract
This paper reports the effects of changes in dose-rate and dose-fractionation on the micronucleus (MN) yield in human lymphocytes exposed to 250 Kv X-rays. For the investigation of dose-rate effects whole blood samples of four healthy donors were irradiated with doses ranging from 1 to 4 Gy given at various dose-rates between 0.2 and 40 Gy/h. For the higher doses (3 and 4 Gy) a decline in the MN yield became apparent when the dose-rate was reduced below 1.6 Gy/h. This effect was enhanced systematically by a further lowering of the dose-rate. For lower doses (1 and 2 Gy) the reduction in the MN yield was less pronounced: only a small effect was observed for two donors when a dose of 2 Gy was administered at a dose-rate of 0.2 Gy/h. In the split-dose experiment a dose of 4 Gy was delivered either as a single exposure or in two fractions of 2 Gy, separated by time intervals ranging from 30 min to 10 h. A continuous decrease of the MN yield with increasing interfraction time is observed: after an initial fast decline a further slight reduction in the MN yield occurs. The observed dose-rate and split-dose effects on the MN yield can be attributed to repair of sublethal damageKeywords
This publication has 32 references indexed in Scilit:
- On the time course of the interactions between DNA breaks in the production of a radiation-induced chromosome exchange aberrationMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 1990
- Use of the Micronucleus Assay for the Selective Detection of Radiosensitivity in BUdR-unincorporated Cells after Pulse-labelling of Exponentially Growing Tumour CellsInternational Journal of Radiation Biology, 1990
- Micronuclei in X-irradiated human lymphocytesMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 1988
- Study on the repair of the radioinduced lesions involved in the formation of chromosomal aberrations in G0 human lymphocytes after exposure to γ-rays and fast neutronsMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 1985
- Radiation induced chromosome aberrations and the poisson distributionRadiation and Environmental Biophysics, 1979
- The effect of changes in dose rate on the yield of chromosome aberrations in human lymphocytes exposed to gamma radiationMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 1976
- The repair of X-ray-induced chromosome aberrations in stimulated and unstimulated human lymphocytesMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 1972
- Lack of recovery from radiation induced chromosome damage in G0 human lymphocytesExperimental Cell Research, 1972
- Radiation-induced human chromosome aberrations: In vitro dose rate studiesMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 1971
- Radiosensitivity and repair time: The repair time of chromosome breaks produced during the different stages of the cell cycleMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 1969