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PubMed2004

Integrated on-chip derivatization and electrophoresis for the rapid analysis of biogenic amines.

We demonstrate the monolithic integration of a chemical reactor with a capillary electrophoresis device for the rapid and sensitive analysis of biogenic amines. Fluorescein isothiocyanate (FITC) is widely employed for the analysis of amino-group containing analytes. However, the slow reaction kinetics hinders the use of this dye for on-chip labeling applications. Other alternatives are available such as o-phthaldehyde (OPA), however, the inferior photophysical properties and the UV lambdamax present difficulties when using common excitation sources leading to a disparity in sensitivity. Consequently, we present for the first time the use of dichlorotriazine fluorescein (DTAF) as a superior in situ derivatizing agent for biogenic amines in microfluidic devices. The developed microdevice employs both hydrodynamic and electroosmotic flow, facilitating the creation of a polymeric microchip to perform both precolumn derivatization and electrophoretic analysis. The favorable photophysical properties of the DTAF and its fast reaction kinetics provide detection limits down to 1 nM and total analysis times (including on-chip mixing and reaction) of <60 s. The detection limits are two orders of magnitude lower than current limits obtained with both FITC and OPA. The optimized microdevice is also employed to probe biogenic amines in real samples.

Biogenic Amines↗
PubMed2004

Enhancing capillary liquid chromatography/tandem mass spectrometry of biogenic amines by pre-column derivatization with 7-fluoro-4-nitrobenzoxadiazole.

This paper describes a capillary liquid chromatography/tandem mass spectrometry (LC/MS/MS) determination of biogenic amines enhanced by pre-column derivatization with 7-fluoro-4-nitrobenzoxadiazole (NBD-F). Biogenic amines including tryptamine, N-methylsalsolinol, histamine, and agmatine were studied. The biogenic NBD-amine derivatives could be quantitatively enriched in-line on 20 x 0.25 mm capillary columns packed in-house with 5 microm C(8) silica particles. In an electrospray ionization (ESI) source these derivatives were ionized effectively, and collision-induced dissociation (CID) produced predominant characteristic ions allowing sensitive MS/MS detection. Agmatine, a potential neurotransmitter/modulator, was taken as a reference compound to study the analytical figures of merit of the procedure. The detection limit of agmatine was estimated to be 0.6 ng/mL (signal-to-noise (S/N) = 3). A linear calibration curve in the range 15-1000 ng/mL agmatine with an r value of 0.9997 was obtained. Tissue samples of rat brain, stomach, and intestine were analyzed. Minimum sample pre-treatment was needed. Each analysis was accomplished within ca. 12 min. The concentration of agmatine was found to be 0.246, 3.31, and 0.058 microg/g wet tissue in the brain, stomach, and intestine, respectively.

4-Chloro-7-nitrobenzofurazan↗
PubMed1975

Interaction of biogenic amines with ethanol.

Ethanol through its primary catabolite, acetaldehyde, competitively inhibits oxidation of aldehyde dehydrogenase substrates. As a consequence biogenic amines form increased quantities of alcohols rather than the corresponding acids. During this biotransformation, condensation reactions between deaminated and intact amines may occur which can yield tetrahydropapaverolines. These compounds are closely related to precursors of opioids which is cause to link ethanol abuse to morphine addiction. There is, however, no pharmacological or clinical evidence suggesting similarities between ethanol dependence or opiod addiction. Acetaldehyde plays an additional role in alkaloidal formation in vitro. Biogenic amines may react with acetaldehyde to form isoquinoline or carboline compounds. Some of these substances have significant pharmacological activity. Furthermore, they may enter neural stores and displace the natural neurotransmitter. Thus, they can act as false neurotransmitters. Some investigators believe that chronic ethanol ingestion leads to significant formation of such aberrant compounds which may then upset autonomic nervous system balance. This disturbance may explain the abnormal sympathetic activity seen in withdrawal. While these ideas about the etiology of alcohol abuse have a definite appeal, they are naturally based on in vitro preliminary work. Much study of the quantitative pharmacology of these compounds in animals is required before judgement can be made as to the merits of the proposed hypotheses. In the meantime, pharmacological studies on the ability of ethanol to depress respiration in the mouse has revealed that unlike opioids or barbituates, respiratory depression induced by ethanol requires the presence in brain of serotonin. This neurotransmitter also mediates the respiratory effects of several other alcohols but curiously, not chloral hydrate, yet this compound is purported to alter biogenic amine metabolism much like ethanol. Thus, the response to ethanol can be pharmacologically separated from other major narcotic classes such as opioids and barbiturates by respiratory depression effects. The specific requirement for serotonin mediation exhibited by ethanol and several other alcohols opens the door for a rational therapeutic approach to the treatment of alcohol abuse. At the same time, this finding tends to lessen the probability that alcoholism is in some way connected with the formation of addictive alkaloids.

Acetaldehyde↗
PubMed1989

Effects of 2,4-dichlorophenoxyacetic acid (2,4-D) on biogenic amines and their acidic metabolites in brain and cerebrospinal fluid of rats.

Effects of single subcutaneous doses of sodium 2,4-dichlorophenoxyacetate (2,4-D-Na) on biogenic amines and their acidic metabolites in rat brain and cerebrospinal fluid (CSF) were analyzed by high pressure liquid chromatography. After 200 mg/kg 2,4-D-Na, the cerebral concentration of 5-hydroxytryptamine (5-HT) was increased slightly and that of 5-hydroxyindoleacetic acid (5-HIAA) roughly 3-fold between 1 and 8 h after the administration. There was also a tendency towards slightly lowered dopamine (DA) levels. No statistically significant changes in brain concentrations of noradrenaline (NA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) or tryptophan (TRY) were found. At the same time, however, the maximal increase in DOPAC, HVA and 5-HIAA concentrations in the CSF was 2.3-5.8-fold. The dependency of biogenic amines and metabolites on 2,4-D-Na dose was studied by injecting s.c. 0, 10, 30 and 100 mg/kg and sacrificing the rats at 2 h. In the brain, there was a dose-dependent increase in concentrations of 5-HIAA (at the two highest doses) and HVA (at the highest dose) while in the CSF those of all three acidic metabolites increased at the two highest doses. The 10 mg/kg dose had no effect. The results agree with the hypothesis that 2,4-D inhibits the organic acid transport out of the brain, which should then result in increased cerebral levels of acidic metabolites of biogenic amines, but it may also have effects on the activity of serotoninergic and dopaminergic neurones.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1987

Computer-operated microspectrofluorimetry to identify formaldehyde-induced fluorophores of biogenic monoamines and precursor substances in models and tissue sections.

By means of a histochemical reaction using formaldehyde vapour (Falck and Owman 1965), biogenic monoamines and precursor substances, i.e., L-DOPA, dopamine, noradrenaline, adrenaline, 5-hydroxytryptophan and 5-hydroxytryptamine, may be converted into fluorophores with specific spectral characteristics, i.e., the emission spectrum, excitation spectrum and fading curve. The registration and correction of the spectral properties and changes induced by acidification with hydrochloric acid vapour or treatment with ammonia vapour, of these formaldehyde-induced fluorophores, are performed by an automated microspectrofluorimeter, developed by modification of a Leitz MPV 2 system. This work deals with the instrumental configuration and certain methodological features in order to identify the fluorogenic biogenic monoamines and precursor substances in models and tissue sections. Registrations of excitation peak values, for the first time extended to a wavelength range from 240-460 nm, are discussed, which enable the calculation of peak ratio values 410/260, 380/320, 320/260 or 385/315, suitable as identification parameters for formaldehyde-induced fluorophores of biogenic monoamines and precursor amino acids.

5-Hydroxytryptophan↗
PubMed1994

Previous stress increases in vivo biogenic amine response to swim stress.

In vivo microdialysis was used to determine biogenic amines in medial prefrontal cortex of rats exposed to eight minutes of swim stress on two consecutive days. On the first day of stress, norepinephrine (NE) efflux increased by 183% over baseline after stress, while dopamine (DA) and serotonin (5-HT) remained stable throughout. On the second day of stress, a robust increase was observed in all 3 neurotransmitters measured, with (NE), (DA), and (5-HT) increasing by 310%, 441% and 496% respectively, and remaining elevated for an hour or more after stress. This suggests that the first exposure to swim stress, while not causing dramatic changes in biogenic amine release, may sensitize biogenic amines in medial prefrontal cortex to subsequent swim stress. Our results also serve as preliminary data concerning the neurochemical changes which might underlie the forced swimming model of "behavioral despair".

Animals↗
PubMedDate not supplied

Alteration of biogenic amines in mouse brain regions by alkylating agents. I. Effects of aflatoxin B1 on brain monoamines concentrations and activities of metabolizing enzymes.

Young adult male CD-1 mice were treated orally twice weekly for three weeks with 0, 0.05, 0.15 or 0.65 mg/kg of aflatoxin B1 (AFB1) in corn oil. Two days after the last dose, the mice were killed by decapitation and the concentrations of the brain catecholamines, norepinephrine (NE), and dopamine (DA), and their metabolites, 3-methoxy-4-hydroxymandelic (VMA), homovanillic acid (HVA) and dihydroxyphenyl acetic acid (DOPAC) and the indoleamine serotonin (5-HT) and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA) were determined by high pressure liquid chromatography in six discrete brain regions. Major effects of AFB1 were found in the concentrations of NE in most brain areas. Endogenous concentrations of DA were increased in the striatum and hypothalamus. The VMA level in the hypothalamus and striatum were decreased by the treatment. The activity of tyrosine hydroxylase, tryptophan hydroxylase, amino acid decarboxylase and monoamine oxidase (the enzymes important in synthetic and degradation pathways of biogenic amines) were investigated. Alterations in biogenic amine concentrations were often consistent with the changes observed in metabolizing enzymes. There was an increase noted in tryptophan hydroxylase activity. Activities of amino acid decarboxylase and monoamine oxidase were increased although the changes were not consistent in all regions or at all dose levels of AFB1. These results suggest that dietary exposure to AFB1 diets may cause alterations in various biogenic amine concentrations and related metabolizing enzymes.

Aflatoxin B1↗
PubMed1995

Biogenic amines and microbial quality of sprouts.

Changes in the biogenic amine content relative to microbial activities in mung bean, lentil and radish sprouts were investigated in prepacked and "home-grown" products. Biogenic amines were determined by ion-exchange chromatography. The major groups of micro-organisms were enumerated by aerobic plate count procedures, using universal and selective media. Putrescine, cadaverine, spermidine, agmatine and spermine were detected in different concentrations, depending on the type of sprouts. In prepacked retail products the total biogenic amine content was higher than in home-grown samples (mung bean 106 micrograms/g compared to 87 micrograms/g; lentil 316 micrograms/g compared to 181 micrograms/g; radish 1486 micrograms/g compared to 252 micrograms/g). It is concluded that sprouting time and storage conditions play a major part in the hygienic quality of legume sprouts.

Agmatine↗
PubMed1995

[Automated pre-column derivatization with o-phthaldialdehyde (OPA)> A new RP-HPLC method for the determination of biogenic amines in food].

A simple, selective and highly sensitive HPLC method for the routine determination of the biogenic amines in food is presented. Sample preparation is based on a rapid amine extraction using 10% trichloroacetic acid and a cation exchange column for extract purification. For the RP-HPLC analysis OPA/2-mercaptoethanol is used for the pre-column derivatisation, followed by fluorescence detection (Ex 345 nm, Em 440 nm). The effects of several factors are discussed. A separation of 15 biogenic amines is achieved within 70 min. The recoveries for histamine, tyramine, putrescine, cadaverine, tryptamine and beta-phenylethylamine are higher than 95%. The detection limits lie between 0.1-0.5 pMol/injection (20 microliters), depending on the amine and a good linearity is achieved in the range from 0.5-500 pMol (r > 0.99). The method has been applied for the determination of biogenic amines in swiss cheese, salami, milk, beer and wine, the repeatability is very good.

Animals↗
PubMed1976

[Biogenic amines in endocrine cells producing polypeptide hormones. The APUD-cells (Pearse) (author's transl)].

APUD-cells (A = Amine, P = Pprecursor, U = Uptake, D = Decarboxylation) are endocrine cells with numerous common characteristics: 1. They produce polypeptide hormones of low molecular weight. 2. They possess specific 1-amino acid decarboxylases to synthesize catecholamines and/or 5-hydroxytryptamine from precursors. 3. A part of the APUD-cell family primarily accumulates biogenic amines within their cytoplasm. 4. All APUD-cells are rich in specific secretory granules that are the morphological substrate for most of their common features.--Enzyme histochemically the APUD-cells represent a rather heterogenous population. The capacity to take up biogenic amines from the blood is confined to a smaller numer of APUD-cells. The concept of the APUD-cells representing a peripheral neurosecretory system (Pearse und Polak, 1971) appears to be premature. It is probable that in several APUD-cells the accumulation of biogenic amines only constitutes a phenomenon without any physiological relevance which, notwithstanding, could explain pathological reactions of APUD-cells.

Animals↗
PubMedDate not supplied

Biogenic amine content in the brains of rats with different levels of resistance to emotional stress.

The levels of biogenic amines and of a number of the products of their metabolism were studied in the hypothalamic nuclei in Wistar and August rats, which have different levels of resistance to emotional stress; levels were also studied in structures functionally and anatomically associated with the hypothalamic nuclei, i.e., the reticular formation of the midbrain, the amygdaloid body, the septum, the locus ceruleus, the dorsal cervical nucleus, and the ventral region of the tegmentum. The genotype was found to determine the level of metabolism of biogenic amines in structures of the central nervous system in conditions of emotional stress. In August rats, the activities of the dopaminergic and serotoninergic systems, which are stress-limiting, decreased to a greater extent during 24-hour immobilization stress. Adrenaline levels in structures of the central nervous system in August rats were higher during stress. Changes in the contents of biogenic amines in the paraventricular and ventromedial nuclei of the hypothalamus in Wistar and August rats could affect the preganglionic neurons of the autonomic nervous system.

Animals↗
PubMed2006

Biogenic amine levels, reproduction and social dominance in the queenless ant Streblognathus peetersi.

Social harmony often relies on ritualized dominance interactions between society members, particularly in queenless ant societies, where colony members do not have developmentally predetermined castes but have to fight for their status in the reproductive and work hierarchy. In this behavioural plasticity, their social organisation resembles more that of vertebrates than that of the "classic" social insects. The present study investigates the neurochemistry of the queenless ant species, Streblognathus peetersi, to better understand the neural basis of the high behavioural plasticity observed in queenless ants. We report measurements of brain biogenic amines [octopamine, dopamine, serotonin] of S. peetersi ants; they reveal a new set of biogenic amine influences on social organisation with no common features with other "primitively organised societies" (bumble bees) and some common features with "highly eusocial" species (honey bees). This similarity to honey bees may either confirm the heritage of queenless species from their probably highly eusocial ancestors or highlight independent patterns of biogenic amine influences on the social organisation of these highly derived species.

Animals↗
PubMed1998

Reduction of 3,4-diaminopyridine-induced biogenic amine synthesis and release in rat brain by gabapentin.

The anticonvulsant drug gabapentin has been shown recently to exhibit anxiolytic and analgesic actions in animals. Such actions have been postulated in part to reflect effects on biogenic amine neuronal activity. Therefore the effects of gabapentin on biogenic amine neuronal activity were assessed by measuring the synthesis of norepinephrine (NE), dopamine (DA) and serotonin (5-HT) in rat brain and on the release of [3H] NE from rat hippocampal slices both in the presence and absence of the depolarizing agent 3,4-diaminopyridine (DAP). Gabapentin (30 and 100 mg/kg, i.p.) did not alter the basal synthesis rates of NE and DA as assessed by the unchanged accumulation of L-dihydroxyphenylalanine (DOPA) in the NE-enriched hippocampus and cortex and in the DA-enriched striatum and mesolimbic areas. Gabapentin also did not alter 5-HT synthesis as determined by the unaltered accumulation of 5-hydroxytryptophan (5-HTP) in the same brain areas. DAP (2 mg/kg, i.p.) induced a modest but significant increase in DOPA accumulation in the hippocampal, mesolimbic and striatal regions. This DAP-induced increase in DOPA accumulation was antagonized significantly in the hippocampus and mesolimbic regions by gabapentin at 30 and 100 mg/kg and in striatum by 100 mg/kg; a 10 mg/kg dose was inactive. DAP increased selectively 5-HT synthesis in hippocampus and this effect was blocked by gabapentin. These findings indicate that the increased synthesis of biogenic amines induced by DAP is antagonized by gabapentin. In support of the in vivo studies, gabapentin was also shown to inhibit the DAP-evoked release of [3H]NE from hippocampal slices. Although the underlying mechanism for these effects is unclear, the present findings nevertheless demonstrate that gabapentin has inhibitory effects on stimulated NE, DA and 5-HT neurons that may be involved in explaining in part the CNS effects of this drug.

4-Aminopyridine↗
PubMed2004

Brain glucose and insulin: effects on food intake and brain biogenic amines of rainbow trout.

The effects of central (intracerebroventricular, 9 microg fish(-1)) and peripheral (intraperitoneal, 4 mg kg(-1)) administration of bovine insulin, as well as the effect of hyperglycemia (oral administration of 1 g glucose fish(-1)) and brain glucodeprivation (intracerebroventricular administration of 2-deoxy-D-glucose) on food intake and levels of brain (telencephalon, preoptic area, and hypothalamus) biogenic amines (serotonin, dopamine, noradrenaline and their metabolites 5-hydroxyindoleacetic acid, and dihydroxyphenylacetic acid) were assessed on rainbow trout ( Oncorhynchus mykiss). Treatment with insulin inhibited food intake after 26 or 52 h of administration, central or peripheral, respectively. This effect was still apparent after 74 h of central treatment. When assessing changes in the levels of biogenic amines after 26 h of central insulin administration, there was a significant increase in the levels of 5-hydroxyindoleacetic acid, and in the ratio of dihydroxyphenylacetic acid/dopamine of insulin-treated fish, in telencephalon and hypothalamus, respectively. These results suggest that peripherally administered insulin is involved in a feedback regulatory loop with food intake and body weight. Moreover, at least part of the effects of insulin could be mediated by hypothalamic dopaminergic activity. The strong hyperglycemia induced by oral administration of glucose did not induce significant changes either on food intake (control versus treated), or in brain levels of biogenic amines. The intracerebroventricular administration of 2-deoxy-D-glucose induced an increase in food intake without altering plasma glucose levels, suggesting that fish brain possesses a control system for detecting hypoglycemia in plasma and therefore keep brain glucose levels high enough for brain function.

Analysis of Variance↗
PubMed2000

Brain biogenic amines and reproductive dominance in bumble bees (Bombus terrestris).

To begin to explore the role of biogenic amines in reproductive division of labor in social insects, brain levels of dopamine, serotonin, and octopamine were measured in bumble bee (Bombus terrestris) workers and queens that differ in behavioral and reproductive state. Levels of all three amines were similar for mated and virgin queens. Young workers that developed with or without a queen had similar amine levels, but in queenright colonies differences in biogenic amine levels were associated with differences in behavior and reproductive physiology. Dominant workers had significantly higher octopamine levels compared with workers of lower dominance status but of similar size, age, and ovary state. High dopamine levels were associated with the last stages of oocyte development irrespective of worker social status and behavior. These results suggest that biogenic amines are involved in behavioral and physiological aspects of regulation of reproduction in bumble bees.

Animals↗
PubMed2005

Distribution and function of biogenic amines in the heart of Nautilus pompilius L. (Cephalopoda, Tetrabranchiata).

Biogenic amines (serotonin and catecholamines), play an important role in the control of the blood flow not only in vertebrates, but also in invertebrates such as cephalopods. In contrast to the well investigated hearts of the a 'modern', coleoid cephalopods, the innervation of the heart of the archaic Nautilus pompilius L. has not been studied in detail. In this study the distribution and effects of biogenic amines in the Nautilus heart were investigated. Serotonin and catecholamines were visualised by the glyxoylic acid induced fluorescence. High performance liquid chromatotography analysis was performed to discriminate between the catecholamines, which showed a high content of noradrenaline in the 4 auricles, the aorta and the ventricle, whereas the ventricle showed a high dopamine content. Adrenaline was found at a very low concentration in the ventricle. Serotonin and dopamine were also immunohistochemically localised to larger nerves and throughout the heart, respectively. In organ bath experiments, the auricles showed little spontaneous activity. After adding serotonin, they displayed rhythmical contractions, which were accelerated dose-dependently by noradrenaline. In summary, these data suggest an important role for biogenic amines in the control of the heart of Nautilus pompilius L., with serotonin possibly stimulating excitatory nerve fibres, whereas noradrenaline is likely to influence the muscle contraction itself.

Animals↗
PubMed1982

Biogenic monoamine turnover in discrete rat brain regions is correlated with conditioned emotional response and its conditioning history.

The content and turnover of dopamine, norepinephrine and 5-hydroxytryptamine (serotonin), and the content of their respective major metabolites were evaluated in 19 discrete brain areas of rats exposed to conditioned emotional response (CER), and in control groups which received either equivalent yoked shock (shock only) or compound stimulus presentation (tone only). On test day, CER animals suppressed responding and exhibited forms of emotional behavior after presentation of the conditioned stimulus (CS); while shock only and tone only control groups, and CER animals which received an acute dose of diazepam prior to testing, did not suppress. Few changes were observed in content of the biogenic amines or their metabolites, suggesting that the behavioral manipulations were acting within normal physiological limits. On the other hand, numerous changes were observed in the utilization of the 3 biogenic monoamines, which were correlated with the conditioning-anxiety (comparisons of CER vs shock only) and the shock history (comparison of shock only vs tone only). These observations are consistent with putative neural pathways in the frontal cortex, septum, nucleus accumbens, amygdala, striatum, hippocampus and brain stem (which utilize specific monoamines), and with discrete brain areas which have been implicated in classical conditioning and CER-related phenomena. These observations suggest roles for biogenic monoamines in mediating or responding to the classical conditioning and emotional components of the paradigm.

Animals↗
PubMed1993

Effect of dietary T-2 toxin on biogenic monoamines in discrete areas of the rat brain.

Acute T-2 toxin treatments alter biogenic monoamine concentrations in the brain; however, these perturbations have not been well documented or demonstrated in feeding trials. In this study, the effect of dietary T-2 toxin on regional brain concentrations of biogenic monoamines and their metabolites was investigated in male rats fed a semi-synthetic diet containing 0, 2.5 or 10 ppm T-2 toxin for either 7 or 14 days. Reduction in feed consumption, feed efficiency and weight gain was observed in rats fed either 2.5 or 10 ppm T-2 toxin. This effect was transient in animals fed the 10 ppm T-2 toxin diet, with feed consumption, feed efficiency and weight gain improving significantly during wk 2. T-2 toxin affected brain biogenic monoamine concentrations. In the nucleus raphe magnus, serotonin, 5-hydroxy-3-indoleacetic acid and norepinephrine increased in a dose-dependent manner, and dopamine increased transiently. In the substantia nigra of rats fed 10 ppm T-2, epinephrine increased after 7 days and norepinephrine decreased after 14 days, when compared with controls. Dihydroxyphenylacetic acid concentrations in the paraventricular nucleus and medial forebrain bundle were lower in T-2 toxin-treated rats than in control animals. The observed effects of T-2 toxin on brain monoamines and the resulting neurochemical imbalance may account for the physiological manifestation of trichothecene intoxication.

Administration, Oral↗