Amines dopamine

MAO is known to occur in at least two forms, MAO A and MAO B, based on substrate selectivity, inhibition by various dmgs, and cloning experiments. Clorgyline [17780-72-2] is a specific inhibitor of MAO A, which displays a substrate specificity for NE and serotonin. Deprenyl [2323-36-6] is a selective inhibitor of MAO B, and displays a substrate preference for P-phenylethylamine and benzyl amine. Dopamine and tyramine are substrates for both enzymes. 

Three amines—dopamine, norepinephrine, and epinephrine—are synthesized from tyrosine in the chromaffin cells of the adrenal medulla. The major product of the adrenal medulla is epinephrine. This compound constimtes about 80% of the catecholamines in the medulla, and it is not made in extramedullary tissue. In contrast, most of the norepinephrine present in organs innervated by sympathetic nerves is made in situ (about 80% of the total), and most of the rest is made in other nerve endings and reaches the target sites via the circu-... 

This soluble enzyme requires pyridoxal phosphate for the conversion of L-dopa to 3,4-dihydroxyphenylethyl-amine (dopamine). Compounds that resemble L-dopa, such as a-methyldopa, are competitive inhibitors of this reaction. a-Methyldopa is effective in treating some kinds of hypertension. 

Certain foods can trigger a migraine attack by effects on neurotransmitter release or metabolism in the brain. For example, a number of foods contain tryptamine which is known to cause release of other amines (dopamine, noradrenaline and 5-hydroxytryptamine) from both nerve terminals and platelets. This release could initiate the sequence of events that results in the migraine attack. Elimination of such foods from the diet can decrease the number of headaches. Compounds that discourage platelet aggregation (e.g. aspirin) may prevent such attacks. 

Methylation S- Adenosylmethionine Transmethylases (cytosol) Catecholamines, phenols, amines Dopamine, epinephrine, pyridine, histamine, thiouracil... 

As a biogenic amine, dopamine belongs to a group of substances produced in the organism by decarboxylation of amino acids. Besides dopamine and norepinephrine formed from it, this group includes many other messenger molecules such as histamine, serotonin, and y-aminobutyric acid. 

Reserpine. As mentioned earlier, the Rauwolfia alkaloid reserpine is noted for its ability to deplete aromatic biogenic amines in nervous tissue of mammals and insects. One of the more remarkable effects of reserpine in humans is to render individuals indifferent to environmental stimuli. Reserpine appears to have a similar effect on insects, although information is still relatively scanty. In the cockroach, Periplaneta americana, reserpine at 50 vg/g causes strong and long-lasting depletion of the aromatic biogenic amines dopamine, octopamine, and 5-hydroxytryptamine (24). Numerous authors have noted that reserpine has tranquilizing effects on insects, e.g., the ant Formica rufa (30) and . americana (24,31). 

Amines—dopamine (DA), noradrenaline (NA, also called norepinephrine), 5-hydroxytryptamine (5-HT, also called serotonin) and acetylcholine (ACh)— commonly co-exist with various neuropeptides, e.g. cholecystokinin (CCK), nemotensin (NT) and thyrotrophin-releasing hormone (TRH) which act as either... 

Kosaka, T., Hama, K., Nagatsu, I. and Wu, J.-Y. (1988) Possible coexistence of amino acid (gamma-aminobutyric acid), amine (dopamine) and peptide (substance P) neurons containing immunoreactivities for glutamic acid decarboxylase, tyrosine hydroxylase and substance P in the hamster main olfactory bulb. Exp. Brain Res., 71, 633-642. 

Bradley Yes, we have tried dopamine and a variety of sympathomimetic amines. Dopamine only acted on neurones which responded to NA but there was not a close correlation between the effects, and on the whole dopamine was less effective than NA. In any case, I do not think there are supposed to be many dopaminergic neurones in the brain stem, so one would not expect dopamine to have independent effects. 

Dopamine also stimulates cardiac Pi-receptors through both direct and indirect mechanisms. It is used to correct hemodynamic imbalances induced by conditions such as shock, myocardial infarction, trauma, or congestive heart failure. As a catechol and primary amine, dopamine is rapidly metabolized by COMT and MAO and, similar to dobutamine, has a short duration of action with no oral activity. It is administered as an intravenous infusion. 

Amphetamine (below), a powerful and dangerous stimulant, is a primary amine. Dopamine, an important neurotransmitter whose depletion is associated with Parkinsons disease, is also a primary amine. Nicotine, a toxic compound found in tobacco that makes smoking addictive, has a secondary amine group and a tertiary one. 

In Scheme 13.40 and as noted above, the action of the iron-containing enzyme tyrosine 3-monooxygenase (EC 1.14.16.2) is shown to effect the conversion of tyrosine (Tyr, Y) and oxygen (O2) to 3,4-dihydroxyphenylalanine (L-dopa), while the cofactor tetrahydrobiopterin undergoes oxidation to 4a-hydroxytetrahydrobiop-terin. Then, the general aromatic-L-amino acid decarboxylase (EC 4.1.1.28), an enzyme that uses pyridoxal as a cofactor, effects the decarboxylation of the bisphe-noUc add to the corresponding amine, dopamine [3,4-dihydroxyphenethylamine, 2-(3,4-dihydroxyphenyl)ethanamine]. 

MIL-101 (Cr)) contains two coordinated labile water ligands per SBU and has been used in similar reactions to HKUST-1. For example, the reaction of MIL-lOl(Cr) with the catechol-functionalized amine dopamine gave a product containing catechol groups on the crystal sm-faces, and these in turn were metalated on treatment with [VO(acac)2]. ... 

Biogenic amines dopamine, serotonin, octopamine, tyramine... 

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