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Updated: Aug 13, 2026

Comprehensive Profiling of Dopamine Regulation in Substantia Nigra and Ventral Tegmental Area
Published on: August 10, 2012
Catechol-O-methyltransferase activity: a determinant of levodopa response
Abstract:
In 14 patients with Parkinson's disease on long-term therapy the erythrocyte catechol-O-methyltransferase activity was found to correlate with the average plasma concentration ratio of 3-O-methyldopa to levodopa and with the fasting plasma concentration ratio of 3-O methyldopa to levodopa. Patients with the higher erythrocyte catechol-O-methyltransferase activities were those with less favorable clinical responses to levodopa. Since erythrocyte catechol-O-methyltransferase activity may reflect the activity of that enzyme in the major metabolizing tissues, catechol-O-methyltransferase activity would seem to be a significant determinant of response to levodopa.
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