Expression of phosphorylated histone H۲AX in blood lymphocytes of patients undergoing angiographic procedures following exposure to X‐rays

Introduction: Coronary angiography is a Diagnostic-Therapeutic method involving ionizing radiation. This method causes to DNA damage with form double stranded breaks which is followed by the phosphorylation of the histone, H۲AX. H۲AX is a key factor in the repair process of damaged DNA which will accumulate to damage sites. In human cells, H۲AX constitutes about ۱۰% of the H۲A protein which is unique due to carboxyl tail. H۲AX the phosphorylated on serine ۱۳۹ in DNA damage sites. Phosphorylated H۲AX protein is called γ-H۲AX. Materials and Methods:  The present study was performed experimentally, after ethics committee approval and written informed consent, twenty-four patients with coronary syndromes, scheduled for Coronary angiography entered into the study. Blood samples from twenty-four patients (mean age ۵۸.۱۶ years) were collected before and ۱۰ minutes after ionizing radiation exposure. Lymphocytes were isolated, fixed and the phosphorylated histone stained with specific monoclonal antibody and analyzed for mean fluorescent intensity using a flow cytometer. Data were analyzed with linear regression, Pearson correlations and Paired t- tests. P<۰.۰۵ was considered to be significant. Results: Blood samples of patients after irradiation showed a significant increase in mean fluorescent intensity compared to before radiation exposure (p<۰.۰۰۱). A significant correlation was shown between dose and mean fluorescent intensity after irradiation (r=۰.۷۳, p<۰.۰۰۱) Conclusion: DNA double stranded breaks are the most significant damages among DNA lesions induced by ionizing radiation. It is a great interest in field of radiology to minimize the risk of adverse radiation effects associated with coronary angiography procedures. γ-H۲AX is a very sensitive method of measuring radiation-induced DNA double strand breaks in the doses of coronary angiography. In the present study, we applied γ-H۲AX to assess the DNA damage during coronary angiography procedures and their effects on DSB. We found a significant increase of γ-H۲AX in blood lymphocytes of ۲۴ patients after Coronary angiography.

کلیدواژه ها:

Ionizing radiation ، H۲AX ، DNA DSB ، Angiography ، Flow cytometry