title: Kinetics of human lymphocyte division and chromosomal radiosensitivity.
abstract: Human blood from normal donors was irradiated with 200 R during the Go phase, and the X-ray sensitivity of early and late dividing lymphocytes in culture was expressed as percentage of induced dicentrics. Cells in first or subsequent divisions were individualized by BrdU-Giemsa techniques. Lymphocytes in the first division at 40, 44 and 72 h after the start of culture had a lower sensitivity to radiation than lymphocytes making their first division at 48, 52 and 56 h. It was observed that: (a) the combination of radiation followed by BrdU did not increase the clastogenic action of X-rays, (b) X-rays in the dose and duration used in our cultures did not increase the frequency of SCEs, and (c) minor changes in culture conditions probably influenced the frequency of SCEs.
mesh_terms: D001782:Blood Donors; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002455:Cell Division / Q000528:radiation effects*; D002478:Cells, Cultured; D002877:Chromosomes, Human / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects*; D009153:Mutagens; D011836:Radiation Tolerance; D012854:Sister Chromatid Exchange; D013997:Time Factors; D014965:X-Rays
chemical_list: D009153:Mutagens; D001973:Bromodeoxyuridine