Trace amines are endogenous molecules distributed in the central nervous system and peripheral tissues that resemble common biogenic amines in terms of subcellular localization, chemical structure, and metabolism. Trace amine-associated receptor (TAAR) is a kind of evolutionarily conserved G-protein-coupled receptors in vertebrates, in which TAAR1 is a functional regulator of monoamine transmitters such as dopamine and serotonin. TAAR1 is widely considered as a potential therapeutic target for schizophrenia, depression and drug addiction. Moreover, TAAR1 is also expressed in peripheral tissues. The homeostasis imbalance of trace aminergic system can induce over-activation of peripheral immune system and central immune inflammatory response. TAAR1 modulators are becoming potential emerging drugs for the treatment of immune-related illnesses, because they may play a major role in the activation or modulation of immune response.
Animals ; Humans ; Receptors, G-Protein-Coupled/metabolism* ; Biogenic Amines ; Dopamine ; Substance-Related Disorders

Some enzymes belonging to the multicopper oxidase (MCO) family can degrade the hazardous biogenic amine (BA) present in food. However, the oxidation of MCO in the process of degrading BAs may reduce its activity and stability, resulting in decreased catalytic efficiency. In this work, an MCO from Lactobacillus fermentum (MCOF) was fused with a Bacillus subtilis catalase (CAT) using different strategies and the fusion enzymes were respectively expressed in Escherichia coli BL21(DE3). The tolerance of eight fused MCOFs to H2O2 increased by 51%-68%, and the stability of CAT&MCOF increased by 17%, compared to the wild type MCOF. Using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) as a substrate, the substrate affinity (Km), the catalytic efficiency (kcat/Km) and the molar specific activity of CAT&MCOF increased by 1.0-fold, 1.7-fold and 1.2-fold than those of MCOF, respectively. The stability of CAT&MCOF under acidic conditions (pH 2.5-4.5) and moderate temperatures (35-55 °C) also improved. Moreover, the degradation rates of putrescine, cadaverine and histamine catalyzed by CAT&MCOF reached 31.7%, 36.0% and 57.8%, respectively, which increased by 132.5%, 45.7% and 38.9% compared to that of MCOF. The improvement on the stability and catalytic efficiency of MCOF by fusion expression with CAT provides a good example for improving the applicability of enzymes through molecular modifications.
Biogenic Amines ; Cadaverine ; Catalase/genetics* ; Escherichia coli/genetics* ; Hydrogen Peroxide

Biogenic amines (BAs) are low molecular weight organic compounds that present in fermented foods. Large amount of ingested biogenic amines can cause allergy or significant symptoms. Reduction of BAs by enzymatic reaction in fermented foods is one of the most efficient methods for removal of biohazard compounds and assurance food safety. In this study, the multicopper oxidase (MCO) gene in the genome of Lactobacillus fermentum was successfully cloned in Escherichia coli BL21 and expressed at 484 U/L. The recombinant MCO was purified by the immobilized metal affinity chromatography method. The optimal reaction temperature and pH for this enzyme was detected to be 50 °C and 3.5. The Km and Vmax values of the recombinant MCO was determined to be 1.30 mmol/L and 7.67×10⁻² mmol/(L·min). Moreover, this MCO dramatically degrades histamine and tyramine by 51.6% and 40.9%, and can degrade other BAs including tryptamine, phenylethylamine, putrescine, cadaverine and spermidine, and was found to be tolerant to 18% (W/V) NaCl. The recombinant MCO is also capable of degrading BAs in soy sauce. The degradation rate of total BAs in soy sauce reaches 10.6% though a relatively low level of enzyme (500 U/L) is used. Multicopper oxidase has the potential to degrade biogenic amines in fermented foods, which lays a foundation for the further application of this kind of food enzymes.
Biogenic Amines ; Cadaverine ; Escherichia coli ; Lactobacillus fermentum ; Oxidoreductases

Animals always seek rewards and the related neural basis has been well studied. However, what happens when animals fail to get a reward is largely unknown, although this is commonly seen in behaviors such as predation. Here, we set up a behavioral model of repeated failure in reward pursuit (RFRP) in Drosophila larvae. In this model, the larvae were repeatedly prevented from reaching attractants such as yeast and butyl acetate, before finally abandoning further attempts. After giving up, they usually showed a decreased locomotor speed and impaired performance in light avoidance and sugar preference, which were named as phenotypes of RFRP states. In larvae that had developed RFRP phenotypes, the octopamine concentration was greatly elevated, while tβh mutants devoid of octopamine were less likely to develop RFRP phenotypes, and octopamine feeding efficiently restored such defects. By down-regulating tβh in different groups of neurons and imaging neuronal activity, neurons that regulated the development of RFRP states and the behavioral exhibition of RFRP phenotypes were mapped to a small subgroup of non-glutamatergic and glutamatergic octopaminergic neurons in the central larval brain. Our results establish a model for investigating the effect of depriving an expected reward in Drosophila and provide a simplified framework for the associated neural basis.
Acetates ; pharmacology ; Animals ; Animals, Genetically Modified ; Avoidance Learning ; physiology ; Biogenic Amines ; metabolism ; Conditioning, Operant ; physiology ; Drosophila ; physiology ; Drosophila Proteins ; genetics ; metabolism ; Feeding Behavior ; drug effects ; physiology ; Instinct ; Larva ; physiology ; Locomotion ; drug effects ; genetics ; Nervous System ; cytology ; Neurons ; physiology ; Octopamine ; metabolism ; RNA Interference ; physiology ; Reward ; Statistics, Nonparametric ; Transcription Factors ; genetics ; metabolism

BACKGROUND: Histamine in food is known to cause food poisoning and allergic reactions. We usually ingest histamine in cooked food, but there are few studies about the influence of cooking method on the histamine level. OBJECTIVE: The purpose of this study was to determine the influence of cooking methods on the concentration of histamine in foods. METHODS: The foods chosen were those kinds consumed frequently and cooked by grilling, boiling, and frying. The histamine level of the food was measured using enzyme-linked immunosorbent assay. RESULTS: Grilled seafood had higher histamine levels than raw or boiled seafood. For meat, grilling increased the histamine level, whereas boiling decreased it. For eggs, there was not much difference in histamine level according to cooking method. Fried vegetables had higher histamine levels than raw vegetables. And fermented foods didn't show much difference in histamine level after being boiled. CONCLUSION: The histamine level in food has changed according to the cooking method used to prepare it. Frying and grilling increased histamine level in foods, whereas boiling had little influence or even decreased it. The boiling method might be helpful to control the effect of histamine in histamine-sensitive or susceptible patients, compared with frying and grilling.
Biogenic Amines ; Cooking* ; Eggs ; Enzyme-Linked Immunosorbent Assay ; Foodborne Diseases ; Histamine* ; Humans ; Hypersensitivity ; Meat ; Methods* ; Ovum ; Seafood ; Vegetables

PURPOSE: Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. MATERIALS AND METHODS: This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. RESULTS: Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. CONCLUSION: Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.
Agmatine* ; Biogenic Amines ; Cell Differentiation ; Cell Proliferation ; Central Nervous System ; MicroRNAs* ; Neural Stem Cells* ; Neurogenesis ; Neurons

PURPOSE: Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. MATERIALS AND METHODS: This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. RESULTS: Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. CONCLUSION: Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.
Agmatine* ; Biogenic Amines ; Cell Differentiation ; Cell Proliferation ; Central Nervous System ; MicroRNAs* ; Neural Stem Cells* ; Neurogenesis ; Neurons

This study was aimed to observe that extremely low frequency magnetic field (ELF-MF) may be relevant to changes of major neurotransmitters in rat brain. After the exposure to ELF-MF (60 Hz, 2.0 mT) for 2 or 5 days, we measured the levels of biogenic amines and their metabolites, amino acid neurotransmitters and nitric oxide (NO) in the cortex, striatum, thalamus, cerebellum and hippocampus. The exposure of ELF-MF for 2 or 5 days produced significant differences in norepinephrine and vanillyl mandelic acid in the striatum, thalamus, cerebellum and hippocampus. Significant increases in the levels of serotonin and 5-hydroxyindoleacetic acid were also observed in the striatum, thalamus or hippocampus. ELF-MF significantly increased the concentration of dopamine in the thalamus. ELF-MF tended to increase the levels of amino acid neurotransmitters such as glutamine, glycine and gamma -aminobutyric acid in the striatum and thalamus, whereas it decreased the levels in the cortex, cerebellum and hippocampus. ELF-MF significantly increased NO concentration in the striatum, thalamus and hippocampus. The present study has demonstrated that exposure to ELF-MFs may evoke the changes in the levels of biogenic amines, amino acid and NO in the brain although the extent and property vary with the brain areas. However, the mechanisms remain further to be characterized.
Animals ; Biogenic Amines ; Brain ; Cerebellum ; Dopamine ; Glutamine ; Glycine ; Hippocampus ; Magnetic Fields* ; Neurotransmitter Agents* ; Nitric Oxide ; Norepinephrine ; Rats ; Serotonin ; Thalamus

OBJECTIVETo establish a method for simultaneously determining vanilmandelic acid (VMA), 5-hydroxyindoleacetic (5-HIAA), 3, 4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in urine by high-performance liquid chromatography (HPLC).

METHODSAfter being filtered with a 0.45 µm membrane syringe filter, the urinary samples were injected directly into the HPLC system using a C18 chromatographic column and a fluorescence detector. The excitation and emission wavelengths were chose as 280 nm and 315 nm, respectively, and the urinary samples were carried with a mobile phase of methanol-0.1 mol/L phosphate buffered solution (V/V = 20:80) at a flow rate of 1.0 ml/min and an injection volume of 20 µl.

RESULTSUsing the method reported here, the correlation coefficients of VMA, 5-HIAA, DOPAC, and HVA were 0.9999, 0.9998, 0.9997, 0.9999, respectively, over linear ranges of 0-2.5, 0-2.0, 0-2.0, and 0-2.5 µg/ml, the minimum detectable concentrations were 0.006, 0.008, 0.012, and 0.0082 µg/ml, the average precisions were 4.2%, 3.7%, 4.9%, and 3.6%, and the recovery rates were 91%∼102%, 93%∼101%, 94%∼101%, and 89%∼ 102%.

CONCLUSIONThis determination method is simple, efficient, accurate, and sensitive for the simultaneous detection of VMA, 5-HIAA, DOPAC, and HVA in urine.

Biogenic Amines ; urine ; Chromatography, High Pressure Liquid ; Homovanillic Acid ; urine ; Humans ; Hydroxyindoleacetic Acid ; urine ; Vanilmandelic Acid ; urine

We experienced a case of an 18-year-old woman who ingested salt-fermented northern sand lance and developed corrosive gastritis. The patient underwent a esophagogastroscopy and had developed a deep ulceration in the antrum. This cases shows that salt-fermented northern sand lance, which is very acidic and includes various biogenic amines, has the possibility of inducing a corrosive injury to the stomach.
Adolescent ; Biogenic Amines ; Female ; Gastritis ; Humans ; Silicon Dioxide ; Stomach ; Ulcer