Cannazza G, Di Stefano A, Mosciatti B, Braghiroli D, Baraldi M, Pinnen F, Sozio P, Benatti C, Parenti C
Dipartimento di Scienze Farmaceutiche, Università degli studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy.
J Pharm Biomed Anal. 2005 Jan 4;36(5):1079-84. doi: 10.1016/j.jpba.2004.09.029.
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 +0.30 V. Mobile phase consisted of 0.05 M citric acid, sodium EDTA 50 microM, sodium octylsulphonate 0.4 nM 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 10nm to 100 microM 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.
建立了一种高效液相色谱（HPLC）方法，用于同时检测口服左旋多巴（L-DOPA）或其前体药物后大鼠纹状体透析液中的左旋二羟基苯丙氨酸（L-DOPA）、多巴胺（DA）、二羟基苯乙酸（DOPAC）和高香草酸（HVA）。色谱系统采用反相C18柱，在+0.30 V下进行电化学检测。流动相由0.05 M柠檬酸、50 microM乙二胺四乙酸钠、0.4 nM辛基磺酸钠组成，pH值为2.9，含8%甲醇（v/v），流速为1 ml/min。校准曲线在10 nM至100 microM的浓度范围内呈线性，在信噪比为3时，L-DOPA的检测下限为125 fmol，DOPAC为50 fmol，DA为250 fmol，HVA为150 fmol。以相对标准偏差表示的重复性（或日内精密度）优于4%。已描述了微透析探针的构建。评估了每个微透析探针的体外相对回收率，结果表明，所有分析物的回收率相似且可重复，变异系数为1%至4%。应用HPLC-EC方法检测口服六种新型潜在L-DOPA前体药物后自由活动大鼠纹状体透析液中L-DOPA、DA、DOPAC和HVA的细胞外水平。
