Detection of early membrane and nuclear alterations of thymocytes upon in vitro ionizing irradiation.

Some membrane and nuclear parameters of rat thymocytes were studied after in vitro X- or gamma-irradiation with doses of 0.5, 1, 2 and 4 Gy followed by incubation for 0.5 to 4 hours at 21-22 degrees C. Early (within the first 2 hours) distinct functional changes of plasma membranes, i.e. increase in Con A binding, autologous rosette-forming capacity, Alcian Blue-induced agglutination, and a decrease in amount of surface negative charges were observed. Meanwhile, the doses applied did not influence the DNA content, and the proportion of pyknotic nuclei did not grossly differ from that of the time-matched controls. However, an increase in AT-rich DNA component was noted. The radiation-induced changes proved to be transient and dose-dependent. In the whole cell populations no irreversible, death-associated events could be detected under the given experimental conditions.