Chromosome aberrations in human lymphocytes at a various duration of cultivation after irradiation

Human peripheral blood lymphocytes were exposed to 60Co gamma-rays (a dose of 3 Gy) and cultivated during seven days in the presence of PHA and BrdU. It was shown that the metaphases of the first and second mitosises occurred during cultivation of the irradiated and unirradiated lymphocytes, being evidence about of irregularity of the coming into division of various fractions of lymphocytes. The time of cultivation did not influence a rate of aberrations in metaphases of the first and second mitosises of the irradiated lymphocytes. During the first and the subsequent mitosises the number of exchange chromosome aberrations decreased and reached a control level in metaphases of the fourth and fifth mitosises. The number of paired fragments at second and third mitosises increased a little and started to decrease only in metaphases of the fourth and fifth mitosises. The decrease in chromosome aberrations with prolongation of the cultivation of lymphocytes after irradiating is a consequence of elimination of cells with chromosome damages during sequential mitotic divisions.