A high performance liquid chromatography (HPLC) method was developed to detected simultaneously l-dihydroxyphenylalanine (l- DOPA), dopamine (DA), dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in rat striatum dilaysates following oral administration of l-DOPA or its prodrugs. The chromatographic system uses a reversed-phase C18 column with electrochemical detection at +0.30V. Mobile phase consisted of 0.05M citric acid, sodium EDTA 50 M, sodium octylsulphonate 0.4nM at pH of 2.9 and 8% methanol (v/v) at a flow rate of 1 ml/min. The calibration curves were linear over the concentration range of 10 nm to 100 M and the lower limits of detections were 125 fmol for l-DOPA, 50 fmol for DOPAC, 250 fmol for DA and 150 fmol for HVA at signal noise to ratio of 3. The repeatability (or intra-day precision), expressed by the relative standard deviation, were better than 4%. The construction of microdialysis probes has been described. The in vitro relative recoveries of each microdialysis probe were evaluated and the results show that they are similar and reproducible for all the analytes with CVs from 1 to 4%. The HPLC–EC method was applied to detect the extracellular levels of l-DOPA, DA, DOPAC and HVA in the striatum dialysates of freely moving rats after oral administration of six new potential l-DOPA prodrugs.
Detection of levodopa, dopamine and its metabolites in rat striatum dialysates following peripheral administration of L-DOPA prodrugs by mean of HPLC-EC
DI STEFANO, Antonio;PINNEN, Francesco Enrico;SOZIO, Piera;
2005-01-01
Abstract
A high performance liquid chromatography (HPLC) method was developed to detected simultaneously l-dihydroxyphenylalanine (l- DOPA), dopamine (DA), dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in rat striatum dilaysates following oral administration of l-DOPA or its prodrugs. The chromatographic system uses a reversed-phase C18 column with electrochemical detection at +0.30V. Mobile phase consisted of 0.05M citric acid, sodium EDTA 50 M, sodium octylsulphonate 0.4nM at pH of 2.9 and 8% methanol (v/v) at a flow rate of 1 ml/min. The calibration curves were linear over the concentration range of 10 nm to 100 M and the lower limits of detections were 125 fmol for l-DOPA, 50 fmol for DOPAC, 250 fmol for DA and 150 fmol for HVA at signal noise to ratio of 3. The repeatability (or intra-day precision), expressed by the relative standard deviation, were better than 4%. The construction of microdialysis probes has been described. The in vitro relative recoveries of each microdialysis probe were evaluated and the results show that they are similar and reproducible for all the analytes with CVs from 1 to 4%. The HPLC–EC method was applied to detect the extracellular levels of l-DOPA, DA, DOPAC and HVA in the striatum dialysates of freely moving rats after oral administration of six new potential l-DOPA prodrugs.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
