||Health Effects Research Lab., Research Triangle Park, NC. Genetic Toxicology Div. ;Duke Univ. Medical Center, Durham, NC. ;Environmental Health Research and Testing, Inc., Research Triangle Park, NC.
Experiments were conducted to compare the chromosome damaging effects of (60)Co gamma radiation on mouse and human peripheral blood lymphocytes (PBLs). Either whole blood or isolated and pelleted mononuclear leucocytes (MNLs) were irradiated with a (60)Co unit to yield exposures of 1, 2, 3, or 4 Gy. In addition, mice were whole body irradiated in vivo with the same doses so that an in vitro-in vivo comparison could be made. The results indicate that mouse PBLs irradiated in whole blood, whether in vivo or in vitro, respond similarly to (60)Co gamma rays as measured by dicentric chromosome formation. In addition, mouse PBLs showed a similar radiosensitivity compared to human PBLs, but because the mouse PBL data were best fitted to an exponential function and the human PBL data to a quadratic function, direct comparisons were difficult to make. Pelleted MNLs from mice were much less sensitive to the clastogenic effects of gamma radiation than whole blood. This is believed due to hypoxic conditions that develop during irradiation and transport. Human PBLs did not show a marked difference whether irradiated in whole blood or as MNLs in tissue culture medium. (Copyright (c) 1988, Academic Press, Inc.)