Radiation-induced oxidative DNA damage, 8-oxoguanine, in human peripheral T cells.
The mechanism leading to the high level of radiosensitivity of T lymphocytes has not yet been fully described. In our previous study, we demonstrated that human peripheral T lymphocytes revealed early apoptotic changes (annexin V-positive) and late apoptotic changes (propidium iodide-positive), at 13 and 24 h after irradiation of 5 Gy, respectively. Changes in mitochondrial membrane potential were observed at 10 h after irradiation of 5 Gy. Subsequently, mitochondrial cytochrome c release was confirmed. In order to elucidate the mechanism which occurs prior to the mitochondrial membrane potential changes, we examined in the present study the radiation dose and the timing of oxidative DNA damage induced in human peripheral T lymphocytes following 10 MV X-ray irradiation. As a result, the production of 8-oxoguanine, i.e., the product of oxidative DNA damage, was clearly identified starting at 10, 6, and 3 h, after 2, 5, and 20 Gy of irradiation, respectively. Therefore, we concluded that it remains necessary to evaluate the extent of radiation-induced oxidative DNA damage. Furthermore, it is important to analyze superoxide radical production and scavenging in terms of the variety of radiosensitivities found among various types of normal tissue cells and neoplastic cells.
Ogawa
Yasuhiro
Y
Department of Radiology, Kochi Medical School, Kochi 783-8505, Japan. ogaway@kochi-ms.ac.jp
Kobayashi
Toshihiro
T
Nishioka
Akihito
A
Kariya
Shinji
S
Hamasato
Shinji
S
Seguchi
Harumichi
H
Yoshida
Shoji
S
D004249:DNA Damage; D005434:Flow Cytometry; D006147:Guanine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000528:radiation effects; D018023:HIV Seronegativity; D006801:Humans; D008856:Microscopy, Fluorescence; D010315:Particle Accelerators; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology / Q000528:radiation effects*; D014965:X-Rays
C024829:8-hydroxyguanine; D006147:Guanine