Inter-individual Differences in Radiation Respone Shown by an in Vitro Micronucleus Assay: Effects of 3-aminobenzamide on X-ray Treatment

Abstract

Among the methods of biological dosimetry of ionizing radiation, we propose the cytokinesis-block micronucleus assay for the measurement of the individual dose absorbed. The dose-response curve was determined for in vitro-irradiated lymphocytes from 25 individuals. The dose-response relationship, fitted by the linear-quadratic function, was F_(MN) = 0·015 (± 0·0016) + 0·043 (± 0·0075) · D + 0·083 (± 0·0045) · D². Our results are compared with those of other authors. 3-aminobenzamide (3AB) combined with X-rays were used to evaluate the micronucleus dose-response relationship in blood from 14 individuals. While it is known that 3AB inhibits poly (ADP-ribose) polymerase activity in vitro, we demonstrate that it also increases the X-ray-induced micronucleus yields. The resulting dose-response relationship varies from subject to subject. The possibility of using this approach to identify the individual radiosensitivity level is discussed.