Possible Interaction: Dihydroxyphenylalanine and Ascorbate

“However, when cultures were pretreated with both l‐DOPA and ascorbate , which prevents the rise in GSH level, protection was lost, in accord with the failure to up‐regulate GSH.”

“In vitro L-DOPA dihydroxyphenylalanine ) is toxic to DA cells and this is prevented by ascorbate '', Ascorbate therapy in early Parkinson's disease delays the need to give L-DOPA by 2 years".”

“The data indicate that: (a) the uptake systems for ascorbate and tocopherols in these cells are inhibited by L‐dopa and/or (b) L‐dopa treatment causes an increase in the rate of utilization of the two nutrients.”

“Thus L‐dopa modulates the cellular dynamics of ascorbate and tocopherol altering cellular antioxidant protection.”

“3,4-Dihydroxyphenylalanine at high concentration is an inhibitor of tyrosine hydroxylation, while tyrosine acts as a substrate inhibitor at concentrations above 8 … can be partially reversed by increasing the concentration of 3,4-dihydroxyphenylalanine from the catalytic level to 8 x 10-4 m. Ascorbate … 3,4-dihydroxyphenylalanine.”