Abstract: Objective To study the effect and mechanism of apoptosis of pheochrom ocytom a cells(PC12) induced by foun aldehyde.Methods The viability of PC12 cells was detected by MTT.The apoptosis was measured by Hoechst 33258 fluorescence staining.The transudation content of LDH was deteun fined by coloun etry reaction.The nitrite content of the cullure medium was measured by nitrate reductase method.The apoptosis of NOS and 1NOS were measured by biochem ical method.The apoptosis of cells was deteun fined by double-staining (Annexin-F1TC/PI) and flow cytometry.The procaspase-3 expression level in PC12 cells treated by founaldehyde was detected by westen blot.Results The content of 20-160 μmol/L foun aldehyde induced apoptosis in PC12 cell The low dose of foun aldehyde(<80μmol/L)m ainly induced apoptosis,while the high dose of foun aldehyde(>80μmol/L)m ainly caused necrosis The content of LDH in supernatant and the amount of NO were gradually increased with the increment of the foun aldehyde concentration.Foun aldehyde promoted the activities of NOS and iNOS in a dose-dependent manner.With the increment of the foun aldehyde concentration,the expression level ofprocaspase-3 was increased gradually.The damage of PC12 cellwas abated significantly in AC-treated group.Conclusion Founaldehyde could induce the apoptosis of PC12 cells in a dose-dependentmanner via caspasepathway.AC could protect PC12 cells against the damage induced by foun aldehyde.