Biogenic amines metabolites

Niederwieser A, Staudenmann W, Wetzel E (1984) High-performance liquid chromatography with column switching for the analysis of biogenic amine metabolites and pterins. J Chromatogr 290 237-246... 

Barchas, J, D., and Berger, P. A. Selected Ion Monitoring Assay for Biogenic Amine Metabolites and Probenecid in Human Lumbar Cerebrospinal Fluid... 

Innumerable applications of chromatographic methods to the analysis of amines appeared in the recent literature concerning biogenic amines, drugs and their metabolites, pesticides and industrial intermediates however, due to the nonvolatile nature of many amines, application of the LC methods in Section IV.D became preponderant. 

The use of HPLC to analyze biogenic amines and their acid metabolites is well documented. HPLC assays for classical biogenic amines such as norepinephrine (NE), epinephrine (E), dopamine (DA), and 5-hydroxytryptamine (5-HT, serotonin) and their acid metabolites are based on several physicochemical properties that include a catechol moiety (aryl 1,2-dihydroxy), basicity, easily oxidized nature, and/or native fluorescence characteristics (Anderson, 1985). Based on these characteristics, various types of detector systems can be employed to assay low concentrations of these analytes in various matrices such as plasma, urine, cerebrospinal fluid (CSE), tissue, and dialysate. 

Numerous assays are also available in the literature for analysis of biogenic amines and their acid metabolites in brain tissue. For example, Chi and colleagues (1999) developed a rapid and sensitive assay for analyzing NE, DA, 5-HT, 5-hydroxyindole-3-acetic acid (5-HIAA), and homovanilHc acid (HVA) in rat brain. The assay used a C18 column (150 x 4.6 mm) coupled to an amperometric electrochemical detector. The mobile phase consisted of a phosphate buffer (pH 4.75) and octane sulphonic acid as an ion-pair reagent in acetonitrile. The sensitivity of the analytes reported was 3-8 pg on column. 

Kanada M, Miyagawa M, Sato M, et al. 1994. Neurochemical profile of effects of 28 neurotoxic chemicals on the central nervous system in rats (1) effects of oral administration on brain contents of biogenic amines and metabolites, hid Health 32 145-164. 

HT) into the nerve terminal, the desmethylated metabolites show selectivity as noradrenaline uptake inhibitors. Thus no TCA can be considered to be selective in inhibiting the uptake of either of these biogenic amines. In the case of TCA overdose, the normal oxidative pathways in the liver are probably saturated, which leads to a disproportionately high concentration of the desmethylated metabolite. The practical consequence of this finding is that toxic plasma concentrations of a TCA are very likely to occur if the dose of the drug is increased in those patients who fail to respond to normal therapeutic doses of the drug. Such a transition to toxic doses could occur suddenly. 

Sanchez, C. and Hyttel, J. (1999) Comparison of the effects of antidepressants and their metabolites on reuptake of biogenic amines and on receptor binding. Cell Mol Neurobiol 19 467-489. 

As outlined previously, initial biological hypotheses of mood disorders were derived from the pharmacological actions of antidepressant drugs, which increase synaptic concentrations of noradrenaline (NA] and/or serotonin. Consequently, the biogenic amine hypothesis was formulated, but it lacks consistent proof that NA and/or serotonin release is indeed diminished. This failure is in part a result of the limited access to relevant brain areas. Measurements of NA and serotonin and their metabolites in blood, urine, and CSF... 

Baker GB, Reynolds GP Biogenic amines and their metabolites in Alzheimer s disease noradrenaline, 5-hydroxytryptamine and 5-hydroxy indole-3-acetic acid depleted in hippocampus but not in substantia innominata. Neurosci Lett 100 335-339, 1989... 

Table 6.2.2 Typical CSF profiles of HVA, 5HIAA and 3-methyldopa (3-MD) for the inborn errors of metabolism associated with a disruption of biogenic amine metabolism. A downward-pointing arrow indicates that a particular metabolite is below the established reference range. An upward pointing arrow is indicative that a metabolite is above the established reference range. WR indicates that the concentration of the metabolite is likely to be within the reference range. AADC Aromatic amino acid decarboxylase, PNPO pyridox(am)ine-5 -phosphate oxidase...

Arai H, Kosaka K, Iizuka R (1984) Changes of biogenic amines and their metabolites in postmortem brains from patients with Alzheimer-type dementia. J. Neurochem. 43 388-393. 

Monoamine oxidases (MAO-A and MAO-B) are mitochondrial enzymes that oxidatively deaminate endogenous biogenic amine neurotransmitters such as dopamine, serotonin, norepinephrine, and epinephrine. MAOs are like EMOs in that they catalyze the oxidation of drugs to produce drug metabolites that are identical in chemical structures to those formed by CYPs. Because the resulting structures are... 

A broader appreciation of Cl in organic mass spectrometry and of subtleties in the use of reagent gases may be obtained from the reviews cited. The literature in the biological sciences in considerable. Some recent examples serve to indicate scope in application biogenic amines [121] drugs and metabolites [116,120,122] and [123] in which a listing of... 

False neurotransmitters. A number of substances, in some cases structurally related to the biogenic amines, are considered to act as false neurotransmitters and GC-MS methods have been applied to their detection. Thus, p-hydroxynorephedrine, a metabolite of (-l-)-amphetamine, can apparently replace noradrenaline and be taken up and released by a similar mechanism to that involved for the catecholamine. A quantitative SIM assay for this metabolite (as the pentafluoropropionyl derivative) has been used in studies of its formation and localisation in brain regions of the rat [473]. Similar methods have been applied to the detection in neural tissue of the N-dealkylated metabolites of methamphetamine, which depletes brain noradrenaline and fenfluramine which depletes serotonin [474]. 

In neuronal function ROS play a role of metabolites immediately participating in the excitation process. In the intracellular space there are both enzymic (cyclooxygenases, monoamine oxidases) and non-enzymic (spontaneous oxidation of biogenic amines) reactions where they are formed. Mitochondrial respiratory chain also provides ROS production in a cell under conditions of changeable oxygen pressure [29,30]. 

Most of the evidence supporting the biogenic amine hypothesis is indirect. Specifically, deficits of norepinephrine and/or serotonin have been difficult to demonstrate. Considerable research into urinary levels of methoxy-hydroxy-phenylethanolamine glycol (MHPG), a norepinephrine metabolite, in depressed... 

Alcohols, phenols, hydroxylamines, and amines can be sulfated, as can endogenous substrates such as steroids, polysaccharides, and biogenic amines. Sulfation can lead to metabolites that are more toxic than their precursors (Fig. 6). 

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