[Application of SCGE-FPG in the study of arsenic-induced oxidative DNA damage in PHA-stimulated and unstimulated human lymphocytes].
OBJECTIVE
To confirm that arsenic (As) induces oxidative DNA damage in phytohemagglutinin (PHA)-stimulated and unstimulated human lymphocytes.


METHODS
The alkaline comet assay combined with specific enzyme (Formamidopyrimidine-DNA glycosylase, FPG) digestion was used to measure As-induced base damage.


RESULTS
The enzyme-sensitive sites were readily detected with the alkaline comet assay after the cells were treated with 10 micromol As for 2 hours. The repair patterns observed for FPG-created DNA single strand breaks (SSBs) in As-treated cells were comparable to those in hydrogen peroxide (H(2)O(2))-treated cells. The enzyme-created SSBs, As-induced base damage, were more significantly revealed in PHA-stimulated lymphocytes. About 63% and 68% of SSBs induced by As and H(2)O(2), respectively, were repaired in PHA-stimulated lymphocytes by 2-hour repair incubation, but about 34% and 43%, respectively, were repaired in unstimulated cells. About 40% and 49% of base damage induced by As and H(2)O(2), respectively, were repaired in PHA-stimulated lymphocytes, but about 19% and 21 %, respectively, were repaired in unstimulated cells.


CONCLUSIONS
As induces oxidative DNA damage in human lymphocytes within micromolar concentrations. Like the damage induced by H(2)O(2), As-induced DNA damage was more slowly repaired in unstimulated lymphocytes.
Li
Dasheng
D
Depatment of Endemic Disease Control, Health and Antiepidemic Station of Guizhou Province, Guiyang 550004, China.
Morimoto
Kanehisa
K
Takeshita
Tatsuya
T
Lu
Yuquan
Y
D000328:Adult; D001151:Arsenic / Q000494:pharmacology*; D004249:DNA Damage; D004260:DNA Repair; D004277:DNA, Single-Stranded / Q000187:drug effects; D043382:DNA-Formamidopyrimidine Glycosylase; D004586:Electrophoresis / Q000379:methods; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008214:Lymphocytes / Q000187:drug effects; D009699:N-Glycosyl Hydrolases; D010084:Oxidation-Reduction; D010835:Phytohemagglutinins / Q000494:pharmacology
D004277:DNA, Single-Stranded; D010835:Phytohemagglutinins; D006861:Hydrogen Peroxide; D009699:N-Glycosyl Hydrolases; D043382:DNA-Formamidopyrimidine Glycosylase; D001151:Arsenic