P-octopamine

Substrates (p-octopamine, dopamine, or 5-hydroxytryptamine) were separated from their N-acetylated products on an Ultrasphere I.P. C18 column (4.6 mm x 250 mm, 5 pm). The mobile phase was comprised of 75 mAf monobasic sodium phosphate, 1 pAf EDTA, 0.35 mAf 1-octanesulfonate (sodium salt), 11% methanol, and 4% acetonitrile. Coulometric detection was used. Detection of p-octopamine and its N-acetylated product was achieved at a potential of +0.75 V, while dopamine, 5-hydroxytryptamine and their products were detected at +0.50 V. 

Fig. 3. GC-MS selected ion-monitoring trace of pHj] and [ Hg] p-octopamine (as their DTFMB-TMS derivatives) from 50 DUM cells incubated with pHg] p-tyramme (A) Detection of endogenous p-octopamine (mass-to-charge ration 537) (B,C) Deu-terated pHg] p-octopamine (mass-to-charge ratio 542) and pHgjp-octopamine (mass-to-charge ration 543), respectively. These deuterated products must have been synthesized by the DUM cells from [ Hg] p-tyramine, because they are not present m the controls. Int. Std. Internal stan d (PH3] m-octopamine) added at the time of derivatization to allow quantification of amines recovered. The y-axis of the figine represents instrument response in arbitrary units. M/Z Mass-to-charge ratio for the particular 10ns being monitored, which in each case corresponds to the molecular weights of the derivatives of the species present.

The locust CNS contains approx 100 DUM neurons, distributed dorsomedially in the ganglia of the ventral nerve cord. These neurons contain and release p-octopamine (10). It is possible, therefore, to remove and maintain m vitro an approximately homogeneous population of DUM cell bodies to monitor the biosynthesis of p-octopamine (Fig. 2). Because of the stereotyped location and lai ge size of these cells, physiological confirmation of their identity prior to removal is unnecessary... 

To follow the biosynthetic route ofp-octopamine, we exposed isolated groups of DUM neurons to deuterated [ H6] p-tyramine for 24 h (4). This procedure yielded significant quantities of pHj] and pHg] p-octopamine (approx 0.04 0.01 ng/cell body), Nondeuterated endogenous p-octopamme was also present (Fig. 3 Table 2). Controls showed no detectable amounts of deuterated p-octopamine (4). The mixture of deuterated (pHsJ and [ Hg] p-octopamine) products is consistent with the [ Hs] p-tyramine containing approx 20% of pHs] p-tyramine and/or the possibility that the hydroxylation of the nng or side chain of the precursor may involve the loss of a hydrogen atom or a deuterium atom. We cannot readily distinguish between these two possibilities. There is only slight evidence for the formation of deuterated dopamine from pHe] p-tyramine this would be seen as a peak at approx 14.75 min. 

Baines, R. A., Zhou, P, Midgley, J. M., Bacon, J. P., and Watson, D. G. (1996) p-Tyramine is a precursor for both p-octopamine and dopamine in the insect nervous system determination by GC/MS of deuterium incorporation. J. Neurochem, submitted for publication. 

ILS. 2004. Bitter orange Citrus aurantium var. amara) extracts and constituents ( )-p-synephrine [CAS No. 94-07-5] and ( )-p-octopamine [CAS No. 104-14-3] Review of toxicological literature. Research Triangle Park, NC Integrated Laboratory Systems, Inc. 

A -methyl-p-octopamine surmise of phaeochromocytoma crises of hypertension in the course of an unknown basal disease normal ... 

The demonstration of a radioprotective effect for numerous biologically active amines in animal and in vitro experiments (phenylethylamine/ tyramine/ " N-methyl-p-octopamine (sympatol)/ 3-hydroxytyramine/ noradrenaline/... 

Aluminum hydroxide Aluminum nicotinate Aluminum isopropoxide Aceglutamide aluminum Tioclomarol Aminoacetonitrile Octopamine HCI p-Ami noacetophenone Acetohexamide... 

Trace amines are a family of endogenous monoamine compounds including (3-phenylethylamine (PEA), p-tyramine (TYR), tryptamine (TRP) and octopamine (OCT). The trace amines share close structural similarity with the well known classical monoamine neurotransmitters such as dopamine (DA), norepinephrine (NE) and serotonin (5-HT). As their name suggests, trace amines occur in comparably much lower abundance than monoamine neurotransmitters. For historical reasons, other endogenous amine compounds which might share some structural similarities with PEA, TYR, TRP or OCT are not referred to as trace amines. 

Trace Amines. Figure 1 The main routes of trace amine metabolism. The trace amines (3-phenylethylamine (PEA), p-tyramine (TYR), octopamine (OCT) and tryptamine (TRP), highlighted by white shading, are each generated from their respective precursor amino acids by decarboxylation. They are rapidly metabolized by monoamine oxidase (MAO) to the pharmacologically inactive carboxylic acids. To a limited extent trace amines are also A/-methylated to the corresponding secondary amines which are believed to be pharmacologically active. Abbreviations AADC, aromatic amino acid decarboxylase DBH, dopamine b-hydroxylase NMT, nonspecific A/-methyltransferase PNMT, phenylethanolamine A/-methyltransferase TH, tyrosine hydroxylase. 

On comparing the activities of the five compounds for which numerical estimates are available in all three assays (synephrine, octopamine, phenylethanolamine, norepinephrine and tyramine) the rank orders of potency in the three systems are Crayfish, 1,2,3t4,5 Cockroach, 2,1,3,4,5 Locust 1,2,3t5,4. This indicates a basic similarity in the responses of these preparations. In each case it was found that ring hydroxylation of the phenylethylamine nucleus was not essential for activity, although p-hydroxylation does yield the best activity. This is particularly evident in the crayfish study where a-MAMBA (a-methylaminomethyl benzyl alcohol), the analog of synephrine which lacks ring substitution, was one of the most active compounds tested, and 3-phenylethanolamine, the corresponding analog of OA, is almost as active as OA. The base compound for this series, phenylethylamine, also shows appreciable activity, but only in the crayfish assay. 

Octopamine (4.41), which carries a p-hydroxyl group, is taken up even more readily into storage vesicles and is, in turn, released when the neuron fires. As an adrenergic agonist, octopamine is, however, only about one-tenth as active as NE therefore, it acts as a very weak neurotransmitter. Compounds such as this behave like neurotransmitters of low potency, and are called false transmitters. On the other hand, octopamine may be a true transmitter in some invertebrates, with receptors that cannot be occupied either by other catecholamines or by serotonin. 

Ribeiro, P. and Webb, R.A. (1983) The occurrence and synthesis of octopamine and other biogenic amines in the cestode Hymenolepis diminuta. Molecular and Biochemical Parasitology 7, 53-62. 

Christensen T. A., Lehman H. K., Teal P. E. A., Itagaki H., Tumlinson J. H. and Hildebrand J. G. (1992) Diel changes in the presence and physiological actions of octopamine in the female sex-pheromone glands of heliothine moths. Insect Biochem. Mol. Biol. 22, 841-849. 

Consequently, it is difficult to know from the early experiments exactly what effects on the fat bixiy can be attributed to which AKH. This can be a source of confusion, as is evident from the previously described example that synthetic Pea-CAH-I and -H fail to stimulate cAMP elevation in preparations of P. americana fat body in vitro, whereas CC extracts elevate cAMP levels (25). Obviously, the elevation of fat body cAMP levels in cockroaches must result from the presence of factors in the CC other than the CAHs. A similar situation probably exists for locusts, as well. These alternative agents could be unidentified peptides or, even, neurotransmitter chemicals, such as octopamine (52). 

P max is the maximal efficacy of the compound against adenylate cyclase in thoracic nerve cord of Periplantea americana L. relative to 1 mM of octopamine Eq. 49... 

Ki is the concentration of octopamine agonist necessary for half-maximal inhibition of pheromone biosynthesis activating neuropeptide (PBAN) binding at 1 p mol/intersegment Eq. 51 [215]... 

Endogenous biogenic amines in the brain include catecholamines [NE (noradrenaline, NA), dopamine (DA), epinephrine (adrenaline)] 5-HT, histamine, and the so-called trace amines (P-phenylethylamine, tyramine, tryptamine, and octopamine). These amines have in common a arylalkylamine stmcture, and all have been implicated in the etiology of one or more psychiatric disorders and/or in therapeutic and/or adverse effects of drugs used to treat such disorders. In this review on depression, the focus in the case of biogenic amines will be on 5-HT, NE, and DA, although epinephrine and histamine and trace amines have also been implicated (see the section on Other Antidepressant Approaches and Targets ). 

---