LC-ESI-MS-MS Method for Monitoring Dopamine, Serotonin and Their Metabolites in Brain Tissue

Abstract

A rapid and precise LC-ESI-MS-MS method for the parallel identification and quantification of dopamine, serotonin and their metabolites (homovanillic acid, 3-methoxytyramine, 3,4-dihydroxyphenylacetic acid and 5-hydroxyindolacetic acid) from rat brain tissue without any pre-analysis adjustment of the sample such as preconcentration or derivatization has been developed. In particular, the reaction-monitoring mode was selected for its extremely high degree of selectivity and the stableisotope-dilution assay for its high precision of quantification. Alternation the ionization polarity in the course of mass spectrometry detection enabled to determine substances susceptible to various ionization modes in only one analysis run. This fact, in combination with an easy pretreatment step, constitutes the method straightforward and time undemanding. The developed method was characterized with a high precision (B19.5%, determined as RSD), an acceptable accuracy (C82.0%, determined as recovery), a low limit of detection (B0.40 ng/100 mg brain tissue) and a low limit of quantification (B0.42 ng/100 mg brain tissue). The method has been applied in a recent animal study. The levels of the studied neurotransmitters have been determined in the rat brain hippocampus, prefrontal cortex, and striatum in an animal model of schizophrenia induced by an acute dose of a dizocilpine.

Sensitive determination of monoamine neurotransmitters, their main metabolites and precursor amino acids in different mouse brain components by liquid chromatography–electrospray tandem mass spectrometry after selective sample clean‐up

“…However, even when compared with these methods, the present method obtained a notable improvement in the sensitivity. Generally, the reported LLOQs determined on matrix‐free samples were within the ranges of 0.3–2, 0.4–15, 0.4–12 and 0.4–135 ng/mL for DA, 5‐HT, 5‐HIAA and DOPAC, respectively (Gonzáles et al, ; He et al, ; Kim et al, ; Kim et al, ; Liu et al, ; Najmanová et al, ; Wojnicz et al, ). The low LLOQs of the present method made it possible to quantitate the substances at low concentrations in small sample masses, for example 2 mg of BO and 10 mg of CB.…”

“…In recent years, LC coupled to a tandem mass spectrometer (MS/MS) via an electrospray ionization (ESI) interface has been introduced for NT analyses, mainly owing to the higher selectivity of this technique. Generally, the LC–ESI–MS/MS methods published so far for brain analysis use simple extraction procedures without further sample clean‐up before injection onto the analytical column (Fuertig et al, ; Gonzáles, Fernández, Vidal, Frenich, & Pérez, ; He et al, ; Huang et al, ; Kim, Choi, Kim, & Kim, ; Kim, Kim, Hong, & Kim, ; Liu et al, ; Marcos et al, ; Najmanová et al, ; Tareke, Bowyer, & Doerge, ; Wojnicz et al, ; Xu et al, ; Zheng et al, ). The crude extract, which is often pre‐concentrated using solvent evaporation, contains matrix components that may affect the accuracy of the results and compromise the lower limit of quantification (LLOQ) owing to interferences and ion suppression in the ESI interface (Peters, Drummer, & Musshoff, ; Srinivas, ; van Eeckhaut, Lanckmans, Sarre, Smolders, & Michotte, ).…”

Letter to the Editor: Does ketamine exert a fast-acting antidepressant effect via inhibition of pro-inflammatory cytokines?

“…Serotonin (5-HT), its metabolite 5-hydroxyindoleacetic acid (5-HIAA) and 5-HT turnover (5-HTIAA/5-HT) were measured in the frontal cortex and the hippocampus by LC-ESI-MS-MS analysis, described in detail elsewhere (Najmanova et al 2011). The whole sample consisted of 23 animals, three animals were excluded form the analyses (two died and one had a post-operative local inflammatory reaction).…”

Highly sensitive isotope-dilution liquid-chromatography–electrospray ionization–tandem-mass spectrometry approach to study the drug-mediated modulation of dopamine and serotonin levels in Caenorhabditis elegans

“…These methods require a pretreatment step, with both recovery parameters and lower substance stability are partly unsatisfactory. However, Najmanova et al published a rapid and precise LC-MS/MS method without cleanup for parallel identification of DA and SRT in brain tissue [19]. But, a LC-MS/MS method for quantification of DA and SRT in Caenorhabditis elegans ( C. elegans ), a common model organism in analytical neurochemistry, is still missing.…”