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synephrine phenylethylamine

Muhammad Zahid Khan, Waqas Nawaz
Human trace amines (TAs) are endogenous compounds, previously almost ignored in human pathology for many reasons (difficulty of their measurement in biological fluids, unknown receptors for elusive amines), are now considered to play a significant role in synaptic transmission within the central nervous system (CNS) acting as neuromodulators. The recent discovery of a novel family of G-protein-coupled receptors (GPCRs) that includes individual members that are highly specific for TAs indicates a potential role for TAs as vertebrate neurotransmitters or neuromodulators, although the majority of these GPCRs so far have not been demonstrated to be activated by TAs...
July 14, 2016: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Bastiaan Venhuis, Peter Keizers, Antoinette van Riel, Dries de Kaste
Food supplements are regularly found to contain pharmacologically active substances. Recently, the food supplement Dexaprine was removed from the Dutch market because it was associated with severe adverse events. Reports to the Dutch Poisons Information Center (DPIC) showed that ingestion of as little as half a tablet caused several cases of nausea, agitation, tachycardia, and palpitations and even one case of cardiac arrest. The remaining tablets of four patients were sent in by different healthcare professionals...
June 2014: Drug Testing and Analysis
Claudio Medana, Paola Calza, Valeria Giancotti, Federica Dal Bello, Manuela Aragno, Claudio Baiocchi
The occurrence of some cases of positive results in anti-doping analysis of octopamine requires clarification as to whether its methylated derivative synephrine could be a metabolic precursor of octopamine itself. Synephrine is a natural phenylethylamine derivative present in some food supplements containing Citrus aurantium, permitted in sport regulations. A simulative laboratory study had been done using a photocatalytic process, to identify all possible main and secondary transformation products, in a clean matrix; these were then sought in biological samples obtained from three human volunteers and four rats treated with synephrine; the parent compound and its new potential metabolic products were investigated in human urine and rat plasma samples...
January 2013: Analytical and Bioanalytical Chemistry
M D Berry
Mining of the human genome has revealed approximately 7000 novel proteins, which could serve as potential targets for the development of novel therapeutics. Of these, approximately 2000 are predicted to be G-protein coupled receptors. Within this group of proteins, a family of 18 mammalian receptors has recently been identified that appear to exhibit selectivity toward the so-called trace amines. The trace amines are a family of endogenous compounds with strong structural similarity to classical monoamine neurotransmitters, consisting primarily of 2-phenylethylamine, m- and p-tyramine, tryptamine, m- and p-octopamine and the synephrines...
January 2007: Reviews on Recent Clinical Trials
David K Grandy
Interest has recently been rekindled in receptors that are activated by low molecular weight, noncatecholic, biogenic amines that are typically found as trace constituents of various vertebrate and invertebrate tissues and fluids. The timing of this resurgent focus on receptors activated by the "trace amines" (TA) beta-phenylethylamine (PEA), tyramine (TYR), octopamine (OCT), synephrine (SYN), and tryptamine (TRYP) is the direct result of 2 publications that appeared in 2001 describing the cloning of a novel G protein-coupled receptor (GPCR) referred to by their discoverers Borowsky et al...
December 2007: Pharmacology & Therapeutics
No abstract text is available yet for this article.
October 1964: Helvetica Physiologica et Pharmacologica Acta
Ai-Ming Yu, Jeffrey R Idle, Tomas Herraiz, Adrian Küpfer, Frank J Gonzalez
The objective of this investigation was to screen for potential endogenous substrates for CYP2D6. Using recombinant CYP2D6, together with hepatic microsomes from CYP2D6-transgenic mice, human liver microsomes, and a specific anti-CYP2D6 monoclonal antibody, it was ascertained that CYP2D6 does not significantly metabolize the endogenous phenylethylamines 2-phenylethylamine, octopamine, synephrine, 3-methoxy-p-tyramine, 4-methoxy-m-tyramine, metanephrine, and normetanephrine, nor the indolethylamines tryptamine, serotonin, 6-methoxytryptamine, and melatonin, nor the beta-carbolines harman, norharman and tryptoline...
June 2003: Pharmacogenetics
C Carpéné, J Galitzky, E Fontana, C Atgié, M Lafontan, M Berlan
Numerous synthetic agonists selectively stimulate beta3-adrenoceptors (ARs). The endogenous catecholamines, noradrenaline and adrenaline, however, stimulate all the beta-AR subtypes, and no selective physiological agonist for beta3-ARs has been described so far. The aim of this study was to investigate whether any naturally occurring amine can stimulate selectively beta3-ARs. Since activation of lipolysis is a well-known beta-adrenergic function, the efficacy and potency of various biogenic amines were compared with those of noradrenaline, isoprenaline, and beta3-AR agonists 4-(-{[2-hydroxy-(3-chlorophenyl)ethyl]-amino} propyl)phenoxyacetate (BRL 37,344) and (R,R)-5-(2-{[2-(3-chlorophenyl )-2-hydroxyethyl]-amino} propyl)-1,3-benzo-dioxole-2,2-dicarboxylate (CL 316,243) by testing their lipolytic action in white fat cells...
April 1999: Naunyn-Schmiedeberg's Archives of Pharmacology
D R Varma, X F Deng, S Chemtob, F Nantel, M Bouvier
We recently reported that tyramine caused concentration-dependent relaxation of rat aorta, which was endothelium independent and was not exerted via alpha 1-adrenoceptors (AR), alpha 2AR, beta 1AR, beta 2AR, or receptors for 5-hydroxytryptamine, histamine, and adenosine. The present studies were done on endothelium-denuded strips to determine structure-vasorelaxant activity after blockade of beta AR by propranolol plus irreversible blockade of alpha 1AR with benextramine. Vasorelaxation under these conditions was limited to noncatecholamines, and their vasorelaxant potencies were methoxyphenamine > tyramine > p-hydroxyephedrine > L-amphetamine > L-ephedrine > phenylethylamine > synephrine > methoxamine > octopamine...
June 1995: Canadian Journal of Physiology and Pharmacology
C H Cashin
1. The effects of some rapidly metabolized sympathomimetic amines, such as beta-phenylethylamine and p-tyramine, in eliciting hypertensive responses to reserpine in the anaesthetized rat, have been studied.2. Retardation of metabolism, by pretreatment with the monoamineoxidase inhibitors iproniazid or phenelzine, causes beta-phenylethylamine (which in untreated rats has no effect) to induce hypertensive responses to reserpine. Tyramine and other hydroxy substituted phenylethylamines are much less active in this respect, probably because of relatively poor lipid solubility...
February 1972: British Journal of Pharmacology
B S Ku, H Takeuchi
The effects of catecholamines, monophenolamines and phenylamines on eight identifiable giant neurons of an African giant snail (Achatina fulica Férussac) were examined to classify these neurons into several categories according to their sensitivities to the various substances. The five neurons, PON (periodically oscillating neuron), TAN (tonically autoactive neuron), 1-VMN (left-visceral multiple spike neuron), d-RPeAN (dorsal-right pedal autoactive neuron) and VIN (visceral intermittent firing neuron), were sensitive to catecholamines...
August 7, 1985: European Journal of Pharmacology
L W Klaassen, A E Kammer
The effect of octopamine on neuromuscular transmission was examined in developing and adult Manduca sexta. Intracellular recordings were made from the dorsal longitudinal muscle (DLM), superfused with solutions containing DL-octopamine or other amines. In untreated adult moths and pharate adults nearly ready to enclose (stage Day 19), stimulation of the motor nerve evokes a large excitatory junction potential (EJP), an active membrane response, and a twitch. In adults and Day 19 animals DL-octopamine (10(-7) to 10(-4)M) has no effect on the amplitude and rise-time of the electrical response in normal saline, but 10(-6) to 10(-4) M DL-octopamine increases the amplitude of the excitatory junction potential recorded in saline containing one-third the normal calcium concentration...
May 1985: Journal of Neurobiology
D G Watson, J M Midgley, R N Chen, W Huang, G M Bain, N M McDonald, J L Reid, C N McGhee
GC-NICIMS has been employed in the analysis of biogenic amines and their metabolites in human urine and human, bovine and porcine aqueous and vitreous humour. Several new chemical derivatization procedures have been developed in order to analyse these compounds. Concentrations of octopamines and synephrines were determined in urine from treated and untreated hypertensive subjects and normotensive individuals; there were no significant differences in concentrations of these metabolites between these groups. Human urine contained several dihydroxy-phenylethylamines which have not been reported as natural metabolites before and also 5- and 6-hydroxydopamine in relatively large amounts...
1990: Journal of Pharmaceutical and Biomedical Analysis
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