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Evaluation of circulating endothelial cells in the rat after acute and fractionated whole-body gamma irradiation

Al-Massarani G., Almohamad K.

Nukleonika

2014

Vol. 59, No. 4

145--151

Purpose: Damage to vascular endothelial cells is a well recognised complication of the irradiation. Our objective was to determine the gamma-irradiation effect on the rat circulating endothelial cells (CEC). Material and methods: Eight-week old rats were divided into four groups: group 1 – rats were exposed to acute whole- -body gamma irradiation with a wide range of single doses (0.5, 1, 2, 4 and 8 Gy), group 2 – rats were exposed to fractionated low doses of irradiation (0.1, 0.5 and 1 Gy) every three days for two months, group 3 as group 2, but followed by two months of rest, group 4 were control animals. CEC (CD146 positive cells) in group 1 were counted following CD146-based immuno-magnetic separation after one day and one week, as well as at the end of experiment in the other groups. Results: Quantifi ed CEC showed that there was a dose-dependent reduction in CEC count in group 1 (one week after irradiation) and group 2. A partial re-population of CEC was observed at the end of experiment in both group 1 and group 2 compared to control group. Group 3 showed a signifi cant increase in CEC levels as compared with group 2 without reaching the control level. Conclusion: The number of CEC (CD146 positive cells) in rats exposed to whole-body gamma irradiation was reduced in a dose-dependent manner and it partly recovered during the two-month interval after irradiation. We suggest that CEC count may be an indicator of the radiation-induced vascular damage.

The influence of fractionated radiation on proliferation, cell cycle and apoptosis of normal human dermal fibroblasts

Adamczyk A., Gasińska A.

Nukleonika

2005

Vol. 50,suppl.2

9-12

The aim of the study was to investigate the changes in proliferation rate, cell cycle and apoptosis of normal skin fibroblasts during fractionated irradiation with a fraction dose of 2 Gy. Fibroblasts were irradiated 5 days per week for 12 days using gamma irradiation. Twenty four hours after each fraction, and for three days after finishing experiment the cells were harvested, fixed, and BrdUrd labelling index (BrdUrdLI), cell cycle and level of apoptosis and debris were assessed. It was found that fractionated irradiation caused disturbances in the proliferation rate and the cell cycle. Irradiation caused also constant, statistically significant increase in the number of G2M cells and level of apoptosis and debris, which was observed even during 3 days after irradiation. Data indicate non equal biological effect of each fraction dose. Block at G2/M phase suggests accumulation of sublethal damage and increased radiosensitivity, which was manifested by elevated level of cell death (apoptosis and debris).