title: Continuous intravenous monitoring of levodopa and 3-O-methyldopa by microdialysis and high-performance liquid chromatography with electrochemical detection.
abstract: Microdialysis, in association with ion-pair reversed-phase high-performance liquid chromatography with electrochemical detection, was applied in vitro for the determination and quantification of levodopa and 3-O-methyldopa in blank spiked plasma and blood. The method presented gave accurate results; the calibration graphs for plasma were linear over the range of the expected values for both compounds. When using a dialysis probe with a membrane length of 1.6 cm at a 5 microliters min-1 perfusion speed, the recovery rate in plasma for levodopa was 30.1% and 68.5% for 3-O-methyldopa. However, less reproducible results were obtained for plasma levodopa levels in the range of 0.5 microliter ml-1 and lower. The microdialysis technique was subsequently successfully applied for the continuous intravenous monitoring of levodopa and 3-O-methyldopa in a levodopa-treated dogs.
authors.affiliation: Department of Neurology, University Hospital, Brussels, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Deleu
authors.forename: S
authors.initials: S
authors.lastname: Sarre
authors.forename: P
authors.initials: P
authors.lastname: Herregodts
authors.forename: G
authors.initials: G
authors.lastname: Ebinger
authors.forename: Y
authors.initials: Y
authors.lastname: Michotte
mesh_terms: D000818:Animals; D002230:Carbidopa / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D003956:Dialysis; D004285:Dogs; D004563:Electrochemistry; D007980:Levodopa / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics; D008297:Male; D008832:Microchemistry; D012015:Reference Standards; D012044:Regression Analysis; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics
chemical_list: D014443:Tyrosine; D007980:Levodopa; D002230:Carbidopa; C008404:3-methoxytyrosine