ABSTRACT
Objective To evaluate influence of benzo(a)pyrene on cell cycle of the human embryonic lung fibroblast at different synchronous stage. Methods Cell cycle distribution were detected by flow cytometry(FCM). Cells were synchronized at cycle G0 stage through 48 hours serum starvation and reenter cell cycle together at a synchronous state after resupplied with whole growth medium contain good serum. Benzo(a)pyrene with a series concentrations were directly used or metabolized active by traditional and modified metabolize active methods through preincubation of S9 and were treated as regent to HELF cells mostly synchronized at G1, S or G2-M stage respectively. Then cell cycle distribution changes were detected 12 h after treatment. Results Serum starvation(48 hours) could synchronize HELF at G0-G1 stage effectively and 10-12 h, 16-18 h, 22-24 h were cycle phase change distinctly time after serum restimulated. Cells were synchronized at G1, S and G2-M stage mostly. Benzo(a)pyrene influence cycle distribution little without metabolize active, while modified methods could metabolize active benzo(a)pyrene well and avoided disturbing effect of S9 on cell cycle in traditional method. Except 2 ?mol/L benzo(a)pyrene treated at 22 h after restimulated caused the percentage of cells at S stage increase, most treatment induced the percentage of cells at S stage decrease which was associated obviously with the increasing dosages. The percentage of cell at S stage decrease at 16 h were more remarkable than other times and the percentage of cell at G2-M increase correspondingly. While the percentage of cell at G1 increase and the percentage of cell at G2-M decrease were obsered when benzo(a)pyrene treated at 10 h and 22 h after restimulated. Conclusion Serum starvation 48 hours and restimulate can synchronize HELF at different stage effectively. Modified metabolize active method is suitable for cell cycle research. Primary influence of benzo(a)pyrene on cell cycle is the decreased percentage of cells at S stage, G1 arrest, G2-M arrest and G1 arrest were occurred when benzo(a)pyrene were treated at G1, S and G2 stage respectively.