caa a22 4500 475846184 CHVBK 20180406123914.0 cr unu---uuuuu 170329e20000501xx s 000 0 eng 10.1007/s000180050046 doi (NATIONALLICENCE)springer-10.1007/s000180050046 Chromosome aberrations, micronuclei, and activity of superoxide dismutases in human lymphocytes after irradiation in vitro [Elektronische Daten] [G. Joksic*, S. B. Pajovic, M. Stankovic, S. Pejic, J. Kasapovic, G. Cuttone, N. Calonghi, L. Masotti, D. T. Kanazir] Abstract.: The goal of this study was to provide data on the dose-dependent production of dicentrics and micronuclei in human lymphocytes irradiated with 22.6 MeV protons and to estimate the possible contribution of intracellular superoxide dismutases (SOD) to the relative biological effectiveness (RBE) of protons. For the dose-response study, heparinized whole blood of a healthy volunteer was irradiated with protons and X-rays employing radiation doses of 0.5-4 Gy. Three biological endpoints were analyzed: chromosomal aberrations, micronuclei, and specific activity of cytosolic (CuZnSOD) and mitochondrial (MnSOD) superoxide dismutases in harvested human blood cells. Dicentric dose-response curves fit a linear-quadratic form (α=0.094±0.006, β=0.032±0.001) induced with X-rays and (α=0.119±0.057, β=0.029±0.014) for 22.6 MeV protons.Protons were more effective than X-rays in producing exchanges, particularly at 0.5 and 1 Gy. In contrast to X-ray irradiated samples where a significant increase in the specific activity of MnSOD was recorded (up to a radiation dose of 1 Gy), irradiation with protons markedly reduced its activity. As a consequence of the reduced activity of MnSOD, the chromosomal dose-response curve became quadratic. The RBE for dicentrics varies with dose (from 2.2 to 1.01) and reduced activity of MnSOD is an important contributor to the RBE of protons. SODs, particularly MnSOD, play an important role in defending DNA from reactive oxygen species. A reduced activity of SOD, particularly MnSOD, is an important contributor to the RBE of protons. Birkhäuser Verlag Basel,, 2000 Key words. Human lymphocytes nationallicence chromosome aberrations nationallicence micronuclei nationallicence superoxide dismutase nationallicence X-ray nationallicence proton nationallicence Joksic* G. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut Pajovic S. B. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut Stankovic M. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut Pejic S. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut Kasapovic J. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut Cuttone G. Southern National Laboratory, Catania (Italy), IT aut Calonghi N. Department of Biochemistry, University of Bologna, Bologna (Italy), IT aut Masotti L. Department of Biochemistry, University of Bologna, Bologna (Italy), IT aut Kanazir D. T. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut https://doi.org/10.1007/s000180050046 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s000180050046 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Joksic* G. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut NATIONALLICENCE 700 1- Pajovic S. B. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut NATIONALLICENCE 700 1- Stankovic M. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut NATIONALLICENCE 700 1- Pejic S. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut NATIONALLICENCE 700 1- Kasapovic J. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut NATIONALLICENCE 700 1- Cuttone G. Southern National Laboratory, Catania (Italy), IT aut NATIONALLICENCE 700 1- Calonghi N. Department of Biochemistry, University of Bologna, Bologna (Italy), IT aut NATIONALLICENCE 700 1- Masotti L. Department of Biochemistry, University of Bologna, Bologna (Italy), IT aut NATIONALLICENCE 700 1- Kanazir D. T. ‘Vinča' Institute of Nuclear Sciences, POB 522, Beograd 11000 (Yugoslavia), Fax + 381 11 344 01 00, e-mail: gjoksic@rt270.vin.bg.ac.yu, YU aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer