关键词: 低剂量辐射, 细胞周期, 凋亡

Abstract: Abstract:Objective To explore the effect of low dose radiation(LDR) on biological characteristics of human mesenchymal stem cells from bone marrow (BM-MSC). Methods The P4,P5,BM-MSC were exposed to X rays at the dose of 50,75,and 100 mGy (dose rate 12.5 mGy•min^-1). The cell growth,cell cycle and apoptosis of BM-MSC treated with LDR were determined. Results Compared iwth control group,the cell growth rates of BM-MSC treated with LDR(50,75,100 mGy) were obviously increased from the fifth day(P<0.05).Compared with control group at the same time,the percentage of G₀/G₁ stage cells gradully decreased (P<0.05),and after treated for 72 h,the growth rate was the lowest. However,the percentage of S stage cells e gradually increased after treated for 48 h and 72 h(P<0.05). The most one was 75mGy group at 72 h(68.88%). The percentages of apoptotic cells had increasing tendency at 24 h and 48 h in all dose groups,while had decreasing tendency at 72 h. Conclusion LDR has hormesis effect on BM-MSC.

Key words: low dose radiation, cell cycle, apoptosis.