Amitriptyline and fluoxetine protect PC12 cells from cell death induced by hydrogen peroxide

OBJECTIVE: To investigate the potential protective effects of amitriptyline and fluoxetine in a catecholamine cell model. METHODS: Cultured rat pheochromocytoma (PC12) cells were pretreated with amitriptyline or fluoxetine for 24 or 48 hours and were then subjected to neurotoxic insult (200 micromol/L hydrogen peroxide). Cell viability was determined by measurement of the reduction product of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT). The enzyme activity of superoxide dismutase (SOD) was determined by a commercial SOD assay kit. RESULTS: The decrease in cell viability induced by hydrogen peroxide was attenuated in PC12 cells pretreated with 100 micromol/L amitriptyline for 24 hours or with 50 micromol/L amitriptyline or 50 micromol/L fluoxetine for 48 hours. Pretreatment with either amitriptyline or fluoxetine was associated with increased SOD activity in PC12 cells. Inhibition of SOD activity with diethyldithiocarbamic acid reduced the cytoprotective action of fluoxetine. CONCLUSIONS: These data suggest that the neuroprotective actions of some antidepressants include the upregulation of SOD activity.