Effects of Different Concentrations of Morphine on Staurosporine-Induced Neurite Outgrowth in Pc12 Cells

Purpose: The present study was conducted to evaluate the effect of different concentrations of morphine on staurosporine-induced neurite outgrowth in PC12 cells. Materials and Methods: PC12 cells were cultured in RPMI1640 culture medium supplemented with 0.2% BSA. Cells were divided into three groups; Ι, ΙΙ and ΙΙΙ, culture in the presence of 50, 100 and 214 nM staurosporine respectively. In each group cells were treated with different concentrations (10-12, 10-10, 10-8, 10-6, 10-4 and 0.0 M) of morphine; treatments 1, 2, 3, 4, 5 and 6 respectively. The percentage of cytotoxicity was performed by lactate dehydrogenase assay. The percentage of death cell was assessed by Hoechst/PI differential staining. Total neurite length was measured.Results: In all groups, the percentage of cytotoxicity as well as the percentage of cell death in treatments 4 and 5 was higher and in treatments 1 and 2 was lower than that of treatment 6 (p<0.05). In group ΙΙΙ, total neurite length in treatments 1 and 2 was higher than that of treatment 6 and in group I, total neurite length in treatments 4 and 5 was lower than treatment 6 (p<0.05). Opioid receptor antagonist (naltrexone) was caused reversed the effects of morphine (p<0.05).Conclusion: Our results suggest that morphine at low concentrations should improve staurosporine-induced neurite outgrowth in PC12 cells.