Mechanisms of ascorbic acid stimulation of norepinephrine synthesis in neuronal cells

► Ascorbic acid enhances norepinephrine synthesis in SH-SY5Y neuroblastoma cells. ► Norepinephrine synthesis increases linearly with intracellular ascorbate. ► Ascorbate enhances tetrahydrobiopterin-stimulated norepinephrine synthesis. ► Ascorbate increases protein expression of tyrosine hydroxylase. ► Ascorbate increases tyrosine hydroxylase expression at physiologic concentrations.