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Shao, C.*; Furusawa, Yoshiya*; Kobayashi, Yasuhiko; Funayama, Tomoo; Wada, Seiichi
FASEB Journal, 17(11), p.1422 - 1427, 2003/08
Times Cited Count：115 Percentile：87.58(Biochemistry & Molecular Biology)The possible mechanism of a radiation-induced bystander response was investigated by using a high-LET heavy particle microbeam, which allows selected cells to be individually hit with precise numbered particles. Even when only a single cell within the confluent culture was hit by one particle of Ar40 or Ne20, a 1.4-fold increase of micronuclei (MN) was detected demonstrating a bystander response. When 49 cells in the culture were individually hit by 1 to 4 particles, the production of MN in the irradiated cultures were about 2-fold higher than control levels but independent of the number and LET of the particles. MN induction in the irradiated-culture was partly reduced by treatment with DMSO, a scavenger of reactive oxygen species (ROS), and it was almost fully suppressed by the mixture of DMSO and PMA, an inhibitor of gap junctional intercellular communication (GJIC). Accordingly, both ROS and GJIC contribute to the above-mentioned bystander response and GJIC might play an essential role by mediating the release of soluble biochemical factors from targeted cells.
Kataoka, Takahiro*; Kanzaki, Norie; Sakoda, Akihiro; Ishida, Tsuyoshi; Tanaka, Hiroshi; Hanamoto, Katsumi*; Terato, Hiroaki*; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*
no journal, ,
We have reported that radon inhalation inhibits oxidative induced damages in some mouse organs due to activation of antioxidant functions. These activations are probably induced by reactive oxygen species following radon inhalation. In this study, we assayed the production of hydrogen peroxide and antioxidant associated substances in brain, lung, heart, liver, stomach, pancreas, kidney, small intestine, and colon in mouse after radon inhalation (1,000 or 10,000 Bq/m
for 24 hours). Results showed that radon inhalation significantly decreased LPO levels in liver (1,000 Bq/m and 10,000 Bq/m) and heart (1,000 Bq/m), suggesting that radon inhalation inhibits oxidative stress. However, On the other hand, radon inhalation at a concentration of 10,000 Bq/m significantly increased the levels of LPO and hydrogen peroxide in lungs only. These findings suggested that radon inhalation at high concentration does not induce oxidative stress in other organs except lung.
