Genetic Instability in Lymphocytes is Associated With Blood Plasma Antioxidant Levels in Health Care Workers Occupationally Exposed to Ionizing Radiation

Abstract

Earlier reports have suggested that exposure to radiation at workplace may induce cytogenetic abnormalities. However, the association between plasma antioxidants and the cytogenetic abnormalities in these patients has not been elucidated till now. Hence, the present study was undertaken to determine the relationship between the cytogenetic abnormalities, plasma antioxidant system, and the radiation exposure levels in men who were occupationally exposed to ionizing radiation. The study included 134 male volunteers, among whom 83 were occupationally exposed to ionizing radiation. Incidence of micronuclei and chromosomal aberration was assessed in lymphocytes. Total and reduced glutathione (GSH), total antioxidant capacity (TAC), superoxide dismutase (SOD), and lipid peroxidation were assessed in the plasma. The micronuclei frequency and chromosomal aberrations were significantly higher in the exposed group in comparison to the nonexposed group ( P < 0.01-0.0001). Similarly, GSH, TAC, and SOD in the blood plasma were significantly higher in the exposed group than the nonexposed group ( P < 0.01-0.0001). However, the level of malondialdehyde, which is an indicator of lipid peroxidation, did not differ significantly between both the groups. Importantly, radiation absorbed dose exhibited a positive correlation with the incidence of micronuclei in blood lymphocytes but not with chromosomal aberrations. This study shows that the susceptibility of peripheral blood lymphocytes to chromosomal damage is associated with plasma antioxidant levels. Furthermore, increased levels of blood plasma GSH, TAC, and SOD in occupationally exposed individuals could be an adaptive measure in response to oxidative stress to protect somatic cell genetic integrity.