Fig 3. Inhibition of cell viability by NO donor was partially suppressed by conditioned medium of benzo[a]pyrene-treated cells.

VSMCs were cultured in serum-free DMEM in the presence or absence of benzo[a]pyrene (10 μmol/L) for 24 h and then the condition medium was collected. Cells were refreshed with DMEM containing SNP (1 mmol/L) as “w”. The condition medium was added to another cell culture dish as “cm”. Cells were co-incubated with SNP and benzo[a]pyrene as “co”. After 24 h, the cell viability was determined by MTT assay (A) and the subdiploid DNA content was determined by flow cytometry (B). Data are represented as mean ± SEM from three independent experiments. *P < 0.05 as compared with control. #P < 0.05 as compared with SNP alone.