title: 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.
mesh_terms: D000368:Aged; D002394:Catechol O-Methyltransferase / Q000032:analysis / Q000097:blood*; D065098:Catechol O-Methyltransferase Inhibitors; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D006801:Humans; D007668:Kidney / Q000201:enzymology; D007980:Levodopa / Q000097:blood / Q000378:metabolism / Q000627:therapeutic use*; D008099:Liver / Q000201:enzymology; D008297:Male; D008750:Methyldopa / Q000097:blood; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000201:enzymology; D013997:Time Factors
chemical_list: D065098:Catechol O-Methyltransferase Inhibitors; D007980:Levodopa; D008750:Methyldopa; D002394:Catechol O-Methyltransferase