Tryptamine receptors

Possibly there is a subclass of 5-HT receptors that would be preferentially activated by tryptamine if its endogenous concentrations were ever adequate. Indeed the term tryptamine receptor as first used by Gaddum to describe the effects of all indole amines may be one to which we should return. 

Arvidsson LE, Hacksell U, Glennon RA. Recent advances in central 5-hydroxy-tryptamine receptor agonists and antagonists. In Jucker E, ed., Progress in Drag Research. Basel Birkhauser Verlag, 1986 365-471. 

Kaumann AJ, Sanders L, Brown AM, Murray KJ, Brown MJ. A 5-hydroxy-tryptamine receptor in human atrium. Br J Pharmacol 1990 100 879-885. 

Hirst WD, Price GW, Rattray M, Wilkin GP. Identification of 5-hydroxy-tryptamine receptors positively coupled to adenylyl cyclase in rat cultured astrocytes. Br J Pharmacol 1997 120 509-515. 

Dumuis A, Bouhelal R, Sebben M, Cory R, Bockaert J. A nonclassical 5-hydroxy-tryptamine receptor positively coupled with adenylate cyclase in the central nervous system. Mol Pharmacol 1988 34 880-887. 

Gaddum JH, Picarelli ZP. Two kinds of tryptamine receptor. Br J Pharmacol Chemother 1957 12 323-328. 

Boess FG, Riemer C, Bos M, Bentley J, Bourson A, Sleight AJ. The 5-hydroxy -tryptamine, receptor-selective radioligand H-3 Ro 63-0563 labels 5-hydroxy-tryptamine receptor binding sites in rat and porcine striatum. Mol Pharmacol 1998 54 577-583. 

It has been demonstrated that N-hydroxytryptophan can be converted to /3-carbolines in two ways (Fig. 41). Pictet-Spengler reaction of 1 with acetals provided the N -hydroxytetrahydro-/8-carbolines (2) (287). A modified Bischler-Napieralski reaction of 1 with trimethylorthoformate gave N -0X0-3,4-dihydro-/3-carbolines (3), the nitrone function of which can undergo 1,3-dipolar cycloaddition with alkenes (288) and nitriles (289), providing isoxazolidine (4) and dehydro-1,2,4-oxadiazoline (5), annulated TBCs, respectively. Nitrone 3 also was obtained by oxidation of the N-hydroxy-j8-carboline 2 with 2,3-dichloro-5,6-dicyano-l, 4-benzoquinone (DDQ). N-Oxygenated TBCs showed no affinity for the benzodiazepine and tryptamine receptors (290). Unfortunately, no toxicity data were recorded for these substituted hydroxylamines. 

GR 11 3808 is a selective (5-HT4-subtype) 5-hydroxy-TRYPTAMINE RECEPTOR ANTAGONIST. It reduces alcohol intake in animal model. It is used as a pharmacological tool. 

Wy 47846) is a tetracyclic structure, a (5HT a) 5-hydroxy-TRYPTAMINE RECEPTOR AGONIST with ANXIOLYTIC activity. 

Recent data indicate that AEA can interact with known GPCRs for other neuronal mediators or with novel GPCRs. AEA was found to exhibit inhibitory activity on 5-hydroxy-tryptamine receptors (Kimura et al., 1998), and both muscarinic and nicotinic acetylcholine receptors (Lagalwar et al., 1999 Oz et al., 2003). Except for the inhibitory effect on nACh alpha7 nicotinic receptors (IC50 = 218 wM), however, AEA appears to modulate the binding and functional activity of 5-HT and acetylcholine only at concentrations (> 5 iM) that are not likely to occur in vivo. Regarding... 

Presynaptic tryptamine receptors are selectively blocked by (—)-cocaine and (+)-cocaine. The tolerance and cross-tolerance to cocaine and J-amphetamine on milk intake of rats was determined. Hydrolysis of [ C]cocaine in human serum has been monitored by t.l.c. and g.l.c. after 1 hour (20% of the cocaine hydrolysed), ecgonine methyl ester was the major product it had not hitherto been observed in humans. After 4 hours (67% hydrolysis), benzoylecgonine and ecgonine (1.6 to 1) were found ti was 2.5 hours in human serum. ... 

The 5-hydroxytryptamine receptor was immu-nolocalized in olfactory tubercle, piriform cortex, nucleus accumbens, island of Calleja, striatum, hippocampus (CAl and dentate gyrus) and the molecular layer of the cerebellum (Gerard et al. 1997). Specific binding of ( H]Ro 63-0563 [4-amino-N-2,6 bis-methylamino-pyridin-4-yl)-benzene sulphona-mide] to recombinant rat and human 5-hydroxy-tryptamine receptors was saturable, rapid, and reversible with equilibrium dissociation constants (Ka) of 6.8 nM and 4.96 nM, respectively (Boess etal. 1998). 

Innes, I. R., Action of dexamphetamine on 5-hydroxy tryptamine receptors, Brit. J. Pharmacol. 21, 427 (1963). 

There is relatively little information available concerning release cmd recovery of serotonin from specific central sites or similarity of action between serotonin and its alleged transmitter counterpart. Sstimulating central neurons by microelectrophoretic tech-niques - But other difficult problems exist especially as they relate to cerebral tryptamine receptors and inhibition of serotonin biosynthesis ... 

Macusine B (51a) stimulates the CNS. It has hypotensive properties, resulting from peripheral vasodilation, as well as ) -adrenergic and a-adrenolytic properties it also affects tryptamine receptors. In high doses, the alkaloid brings about clonic convulsant effects (497,498,491). 

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