OBJECTIVETo study the effects of nickel-refining dusts on DNA damage in mouse NIH/3T3 cell.

METHODDNA damage of mouse NIH/3T3 cell induced by two nickel-refining dust samples was determined with single cell gel electrophoresis (SCGE) technique.

RESULTS(1) Under the condition of the same treatment time, the tailed cell (%) of NIH/3T3 cells increased with the increase in doses of nickel-refining dusts (35.5%, 69.7%, 85.2%, 41.3%, 75.7%, 89.2% respectively except for sample 2, 50 microg/ml, 24 h group), and DNA strand breaks reached the peak value at 4 h of exposure; (2) When we treated the NIH/3T3 cells with the same dose of nickel-refining dusts, the tail rate at 4 h was higher than those at 2 h and 24 h of exposure; (3) Both sample 1 and sample 2 with different doses of nickel-refining dusts could induce higher comet tail, DNA%, tail length (except for 12.5 microg/ml), extent of TM (except for sample 1, 12.5 microg/ml) than in control group (P < 0.05). The DNA damage range was significantly increased in different tested doses of nickel-refining dusts and the damage range reached the peak value when the cells were treated for 4 h.

CONCLUSIONNickel-refining dusts could induce different degree DNA damage in NIH/3T3 cells.