Dose-response And Time-effect Between γ-rays Radiation And Histone H2AX Phosphorylation (γHZAX) Of Mononuclear Bone Marrow Cell

Purpose: Phosphorylation of histone H2AX(γH2AX) occurs rapidly in response to the presence of DNA double strand breaks. We examined the possibility that expression of phosphorylated H2AX could provide information on normal hemopoietic tissue radiobiological effect to low dose total body irradiation.Methods: 96 Female Kunming mice were divided into eight groups, according to their exposure to 0-800mGy ⁶⁰Co-ray irradiation. Mice were sacrificed at 24h,48h and72h after LDR, to collect mononuclear bone marrow cell. H2AX intensity were detected using Flow cytometry ofγH2AX antibody-stained single cells.Results: a J-shaped curve is found from the level ofγH2AX expression by both of single and double staining methods. 100mGyγ-ray induced a minimum stimulation for DSB in all the groups.Conclusions: 1. H2AX,as an indicator of DSB, has the potential to provide useful information on normal bone marrow cells response to ionizing radiation. 2.The results suggest that LDR induces hematopoietic hormesis, as demonstrated by the analysis ofγH2AX expression.