[Effects of 2,450 MHz microwave on DNA damage induced by three chemical mutagens in vitro].
OBJECTIVE
To study the combined damage-effects of low-intensity 2,450 MHz microwave (MW) with three chemical mutagens on human lymphocyte DNA.


METHODS
DNA damage of lymphocytes exposed to microwave and(or) with chemical mutagens were observed at different incubation time (0 h or 21 h) with comet assay in vitro. Three combination-exposure ways of MW with chemicals were used: MW irradiation before chemical exposures, simultaneously exposed to MW and chemicals and MW irradiation after chemical exposures. The three chemical mutagens were mitomycin C (MMC, DNA crosslinker), bleomycin (BLM, radiometric agent), methyl methanesulfonate (MMS, alkylating agent). The exposure time of MW and chemical mutagens were 2 h and 3 h respectively.


RESULTS
The differences of comet tail length between MW group and control group were not significant when lymphocytes were incubated for 0 h or 21 h (P > 0.05). However, when lymphocytes were incubated for 21 h with 30.00 micro mol/L of MMC, the comet tail lengths of MW + MMC group, MW-MMC group and MMC + MW group were (18.00 +/- 5.96), (21.79 +/- 11.47) and (22.32 +/- 8.10) micro m respectively; while with 3.00 micro mol/L of MMC, the comet tail lengths were (8.99 +/- 3.75), (12.40 +/- 5.35) and (14.00 +/- 5.38) micro m respectively, which were significantly higher than those of corresponding MMC groups [(9.42 +/- 3.34) and (6.50 +/- 2.89) micro m, P < 0.01 or P < 0.05]. The DNA damage of MW plus BLM groups and MW plus MMS groups were not significantly different from the corresponding BLM and MMS groups (P < 0.05).


CONCLUSIONS
2 450 MHz MW (5 mW/cm(2)) did not induce DNA damage directly, but could enhance the DNA damage effects induced by MMC. The synergistic effects of 2 450 MHz MW with BLM and MMS were not obvious.
Zhang
Mei-bian
MB
Institute of Environmental and Occupational Health, Medical School of Zhejiang University, Hangzhou 310006, China.
Jin
Li-fen
LF
He
Ji-liang
JL
Hu
Jun
J
Zheng
Wei
W
D001761:Bleomycin / Q000494:pharmacology; D020552:Comet Assay; D004247:DNA / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D004249:DNA Damage; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D008872:Microwaves / Q000009:adverse effects*; D016685:Mitomycin / Q000494:pharmacology; D009153:Mutagens / Q000494:pharmacology*; D013997:Time Factors
D009153:Mutagens; D001761:Bleomycin; D016685:Mitomycin; D004247:DNA; D008741:Methyl Methanesulfonate