[Simultaneous rapid detection of eight neurotransmitters in rat tissues,blood and urine samples by UPLC-MS/MS].

Ultra performance liquid chromatography-tandem mass spectrometry( UPLC-MS/MS) was used to establish the simultaneous determination method of eight neurotransmitters in brain,liver,kidney,adrenal gland,serum and urine,including serotonin,5-hydroxyindole acetic acid,epinephrine,norepinephrine,dopamine,glutamic acid,γ-aminobutyric acid,and acetylcholine,and then investigate the distribution characteristics of neurotransmitters in rat tissues,blood and urine. Waters ACQUITY UPLC BEH C_(18) column( 2. 1 mm×100 mm,1. 7 µm) was used,with 0. 3% formic acid solution-acetonitrile as the mobile phase for gradient elution.Multiple reaction monitoring( MRM) scanning method under positive mode by atmospheric pressure electrospray ion source( ESI) was also performed to establish the detection method of neurotransmitters for methodological research. The plasma,urine and tissues of normal rats were pre-treated including homogenization,centrifuging,and protein removal,then the 2 µL supernatant was injected for analysis. The results showed that eight kinds of neurotransmitters could be accurately determined within 7 min,with linear correlation coefficients all greater than 0. 99. This method showed high accuracy and good precision,with specificity,stability,extraction recovery and matrix effects all complying with the biological sample analysis requirements. The most abundant transmitters in the brain,liver,kidney,kidney gland,blood and urine were γ-aminobutyric acid,glutamic acid,glutamic acid,adrenaline,glutamic acid and dopamine.The method is sensitive,rapid,precise,accurate and specific,and can be used for simultaneous quantitative analysis of eight neurotransmitters in biological samples. The investigation of the distribution ratio of transmitters in rats is of important significance to disease prevention and treatment.

LC-MS/MS based studies on the anti-depressant effect of hypericin in the chronic unpredictable mild stress rat model.

ETHNOPHARMACOLOGICAL RELEVANCE: St John׳s Wort (Hypericum perforatum, SJW) is a widely used herbal medicine in western countries but also an important Uygur drug in China. Hypericin (HY) is the main components in SJW extracts, which is used to treat fatigue, weakness, and mild depression. The aim of this study was to investigate the anti-depression effects of HY on chronic unpredictable mild stress (CUMS) model rats and identify the possible mechanisms. MATERIALS AND METHODS: In this study, the protective effects of HY on CUMS-induced depression in rats were investigated by using a combination of behavioral assessments and urinary metabolites analysis. Urinary metabolites analyses were performed using LC-MS/MS in conjunction with principal components analysis (PCA) after oral administration of either HY or Venlafaxine (VF) for 27 days. During the procedure of experiment, food consumption, body weight, adrenal gland, thymus and spleen indices, behavior scores, sucrose consumption, and stress hormone levels were measured. RESULTS: Changes in the classic behavioral tests and pharmacological biochemical indices reflected that HY alleviated the symptoms of depression in a shorter period than VF, which was used as positive control for antidepression. Metabolites analysis of urine revealed that HY affected excitatory amino acids and monoamine neurotransmitter metabolites. Remarkably, urinary valine was increased remarkably by HY, even much higher than CUMS group. These results provide important mechanistic insights into the protective effects of HY against CUMS-induced depression and metabolic dysfunction. CONCLUSION: As the most important active ingredient in SJW extracts, HY possesses the better protective effect against CUMS-induced depression symptoms and metabolic disturbances.

A randomized targeted amino acid therapy with behaviourally at-risk adopted children.

BACKGROUND: Increasing numbers of children are at-risk for behavioural and emotional disorders, a phenomenon contributing to increased use of pharmacological interventions for paediatric clients. Adverse side effects and other risks associated with pharmacological approaches have helped fuel interest in nutritional interventions for behaviourally at-risk children. METHODS: The current randomized clinical trial evaluates the efficacy of a neurochemical intervention involving the glutamine and glutamate analogue L-theanine and 5-hydroxytryptophan, the precursor for serotonin, with children adopted from traumatic backgrounds. RESULTS: Results include significant increases in urinary levels of the biomarkers for serotonin and gamma-aminobutyric acid, coupled with significant decreases in parent reports of the children's behaviour problems. CONCLUSIONS: While further research is needed, these initial findings are encouraging and are consistent with a growing number of studies indicating the efficacy of nutritional approaches to help behaviourally at-risk children.

Detection of 28 neurotransmitters and related compounds in biological fluids by liquid chromatography/tandem mass spectrometry.

This work presents two liquid chromatography/tandem mass spectrometry (LC/MS/MS) acquisition modes: multiple reaction monitoring (MRM) and neutral loss scan (NL), for the analysis of 28 compounds in a mixture. This mixture includes 21 compounds related to the metabolism of three amino acids: tyrosine, tryptophan and glutamic acid, two pterins and five deuterated compounds used as internal standards. The identification of compounds is achieved using the retention times (RT) and the characteristic fragmentations of ionized compounds. The acquisition modes used for the detection of characteristic ions turned out to be complementary: the identification of expected compounds only is feasible by MRM while expected and unexpected compounds are detected by NL. In the first part of this work, the fragmentations characterizing each molecule of interest are described. These fragmentations are used in the second part for the detection by MRM and NL of selected compounds in mixture with and without biological fluids. Any preliminary extraction precedes the analysis of compounds in biological fluids.