Continuous intravenous monitoring of levodopa and 3-O-methyldopa by microdialysis and high-performance liquid chromatography with electrochemical detection.
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.
Deleu
D
D
Department of Neurology, University Hospital, Brussels, Belgium.
Sarre
S
S
Herregodts
P
P
Ebinger
G
G
Michotte
Y
Y
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
D014443:Tyrosine; D007980:Levodopa; D002230:Carbidopa; C008404:3-methoxytyrosine