The effect of L-ascorbate on catecholamine biosynthesis.
l-Ascorbate stimulates the enzymic hydroxylation of phenylalanine in vitro by recycling tetrahydrobiopterin, which reduces O(2) utilized in the reaction. It is suggested that ascorbate might have a similar function in vivo; this would explain the apparent regulation of tyrosine hydroxylase and tryptophan hydroxylase activities by this vitamin.
Animals↗