title: Cysteine elevation in levodopa-treated patients with Parkinson's disease.
abstract: Homocysteine, cysteine, and cysteinyl-glycine are all metabolically interrelated. Levodopa/decarboxylase inhibitor (LD/DCI) administration increases total homocysteine (tHcy) plasma levels. Objectives were to investigate associations between LD/DCI intake, concentrations of tHcy, cysteine, and cysteinyl-glycine in PD patients and healthy controls. Cysteine levels were significant lower in controls and PD patients with tHcy below the treshold of 15 [micromol/L] when compared with PD patients with tHcy above 15. Cysteinyl-glycine did not significantly differ between the three cohorts. Significant associations appeared between tHcys and cysteine in PD patients. tHcy and cysteine concentrations correlated to LD/DCI intake and severity of PD. The cysteine increase may be due to the significant higher dosing of daily LD/DCI and the significant higher morning LD/DCI dose 1 hour before blood sampling in PD patients with tHcy above 15 when compared with the remaining PD patients and the controls. The correlation outcomes support the view that LD/DCI intake may also increase cysteine.
authors.affiliation: Department of Neurology, St. Joseph Hospital Berlin-Weissensee, Gartenstrasse 1, Berlin,Germany. th.mueller@alexius.de or
authors.forename: Thomas
authors.initials: T
authors.lastname: Müller
authors.forename: Wilfried
authors.initials: W
authors.lastname: Kuhn
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D003545:Cysteine / Q000097:blood*; D005260:Female; D005998:Glycine / Q000097:blood; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood* / Q000188:drug therapy*; D012720:Severity of Illness Index
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa; D003545:Cysteine; D005998:Glycine