Linear Dose Response of Acrocentric Chromosome Associations (Aca) To Gamma Irradiation In Human Lymphocytes

Abstract

Purpose: The frequency of acrocentric chromosome associations (ACA) was studied to determine the possible dose-response relation with low doses of gamma irradiation in lymphocytes. Methods: Peripheral blood collected from three healthy donors were irradiated with 0, 0.1, 0.25, 0.5, 0.75, and 1 Gy gamma radiation. Chromosomal preparations were made after 48 hrs culture as per the standard guidelines. Results: The average number of ACA and ACA % were increased significantly with an increase in a dose. The D-G and D-D type of association was most prominent and showed a dose-dependent increase. The ACA frequency in irradiated lymphocytes showed an increase concerning the dose. The fitted regression equation was y=0.4759x+0.1663 (R2=0.9635; p=0.0005). An assessment of dicentric chromosomes (DC) was carried for the same slides. The correlation curve was prepared for ACA frequencies versus DC frequencies, resulting in a regression equation as y=8.659x+0.2.37 (R2=0.8275; p=0.0119). Conclusion: Our results showed an increase in frequencies of ACA in irradiated lymphocytes with an increase in radiation dose and followed a similar linear trend with DC frequency, thus, ACA may serve as a candidate cytogenetic biomarker for radiation biodosimetry especially for low radiation doses.