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, H2AX. H2AX is a key factor in the repair process of damaged DNA which will accumulate to damage sites. In human cells, H2AX constitutes about 10% of the H2A protein which is unique due to carboxyl tail. H2AX the phosphorylated on serine 139 in DNA damage sites. Phosphorylated H2AX protein is called γ-H2AX.
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 58.16 years) were collected before and 10 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<0.05 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<0.001). A significant correlation was shown between dose and mean fluorescent intensity after irradiation (r=0.73, p<0.001)
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-H2AX 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-H2AX to assess the DNA damage during coronary angiography procedures and their effects on DSB.
We found a significant increase of γ-H2AX in blood lymphocytes of 24 patients after Coronary angiography.