[A study on lens epithelial cell DNA damage induced by hydrogen peroxide in rat and its repair].
OBJECTIVE
The induction and repair of DNA single-strand breaks (SSBs) were measured in primary cultured infant rat lens epithelial cells (RLECs) following hydrogen peroxide (HP) exposure, and the influential factors were detected.


METHODS
Utilizing nick translation methodology which utilizes incorporation of labeled nucleotides at the sites of DNA SSBs to sensitively quantitate the damage, we studied the effects of temperature, doses of HP and trace amount of selenium on cell survival.


RESULTS
The number of DNA SSBs at 37 degrees was higher than that at 4C (P < 0.01). Significant numbers of SSBs were detected after being insulted by as low as 36.4 mumol/L hydrogen peroxide for 12 minutes 4 degrees (P < 0.05). Repair rapidly initiated and almost completed in 60 minutes after mild damage, and it was unable to repair when the DNA damage was induced by HP at toxic concentration. Trace selenium was added to the culture and incubated for 24 hours, then the number of SSBs was significantly decreased (P < 0.01).


CONCLUSIONS
At 37 degrees HP may induce DNA SSBs in RLECs. HP induces the SSBs in a dose dependent manner. The DNA SSBs can not be repaired after severe damage. Trace selenium can decrease the degree of susceptibility to oxidative damage in infant RLECs.
Qin
H
H
Department of Ophthalmology, Third Hospital, Beijing Medical University.
Zhao
G
G
Wu
H
H
D000818:Animals; D002478:Cells, Cultured; D004249:DNA Damage; D004260:DNA Repair; D004847:Epithelial Cells / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000633:toxicity*; D007908:Lens, Crystalline / Q000166:cytology* / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D018038:Sodium Selenite / Q000494:pharmacology
D006861:Hydrogen Peroxide; D018038:Sodium Selenite