Methyl group-donating vitamins elevate 3-O-methyldopa in patients with Parkinson disease.

Abstract

BACKGROUND:

Levodopa (LD)/dopa decarboxylase inhibitor application increases 3-O-methyldopa (3-OMD) concentrations in association with methyl group transfers, which demand for the conversion of methionine to homocysteine. This accompanying reaction is partially reversible by methyl group-donating vitamins.

OBJECTIVE:

The objective of this study was to investigate of the effect of methyl group-donating vitamins on 3-OMD synthesis in LD-treated patients with Parkinson disease.

METHODS:

We determined LD, 3-OMD, and homocysteine plasma concentrations in relation to daily LD dosage administered orally or as duodenal infusion with and without vitamins.

RESULTS:

Orally LD-treated patients with Parkinson disease had a lower LD dose compared with the ones on an LD infusion, but LD, 3-OMD, and homocysteine bioavailability was not different. The same 3-OMD and homocysteine accumulation despite the applied higher LD dosage during the infusion indicates a limited methylation capacity. Higher 3-OMD concentrations occurred during chronic vitamin supplementation, whereas the other parameters did not vary from the ones before vitamin intake.

CONCLUSIONS:

Vitamin supplementation elevated methylation of LD to 3-OMD. We suggest that, to a certain extent, plasma levels of homocysteine may reflect methyl group donation resources, whereas 3-OMD concentrations may mirror methylation capacity.

• Authors: Thomas Müller, Constanze Jugel, Siegfried Muhlack, Fabian Klostermann
• Journal: Clinical neuropharmacology (Clin Neuropharmacol) 2013 Mar-Apr Vol. 36 Issue 2 Pg. 52-4 ISSN: 1537-162X [Electronic] United States
• PMID: 23503547 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Antiparkinson Agents
• Biomarkers
• Vitamins
• Homocysteine
• Tyrosine
• Levodopa
• 3-methoxytyrosine

Topics

• Aged
• Aged, 80 and over
• Antiparkinson Agents (metabolism, therapeutic use)
• Biomarkers (metabolism)
• Cohort Studies
• Female
• Homocysteine (blood, metabolism)
• Humans
• Levodopa (metabolism, therapeutic use)
• Male
• Methylation (drug effects)
• Middle Aged
• Parkinson Disease (drug therapy, metabolism)
• Pilot Projects
• Tyrosine (analogs & derivatives, biosynthesis)
• Vitamins (metabolism, pharmacokinetics)