Quantification of Dopamine in Brain Microdialysates with High-Performance Liquid Chromatography-Tandem Mass...

The dopamine level in the brain and the mesolimbick dopaminergic system are responsible for nicotine addiction. In the present study, extracellular dopamine in nucleus accumbens was collected by a brain microdialysis technique. Also a sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method with a gradient elution procedure was developed for a precise determination of dopamine in brain dialysate. The retention time of dopamine was about 11.32 min. The linear range was 20 - 1000 pg/mL. The limit of detection (LOD) and the limit of qualification (LOQ) were 5 and 20 pg/mL, respectively. The recovery ranged from 98.2 to 109.0%, and both the intra-RSD and inter-RSD were below <9%, respectively. The probe recovery for dopamine in this brain microdialysis experiment was about 25%. Finally, the dopamine concentrations in the rat brain microdialysates were determined, and the pharmacokinetics of extracellular dopamine in the brain nucleus accumbens after an intravenous injection of nicotine was successfully evaluated.