Serotonin receptors for

Several different types of serotonin receptor (for example, S-HTi / 5-HT2A/ 5-HT2C/ 5-HTib/id) have been associated with the motor side effects of the SSRIs which may arise should these drugs be administered in conjunction with a monoamine oxidase inhibitor. The 5-HT3 receptor is an example of a non-selective cation charmel receptor which is permeable to both sodium and potassium ions and, because both calcium and magnesium ions can modulate its activity, the 5-HT3 receptor resembles the glutamate-NMDA receptor. Antagonists of the 5-HT3 receptor, such as ondansetron, are effective antiemetics and are particularly useful when... 

Future Outlook for Antidepressants. Third-generation antidepressants are expected to combine superior efficacy and improved safety, but are unlikely to reduce the onset of therapeutic action in depressed patients (179). Many dmgs in clinical development as antidepressive agents focus on estabhshed properties such as inhibition of serotonin, dopamine, and/or noradrenaline reuptake, agonistic or antagonistic action at various serotonin receptor subtypes, presynaptic tt2-adrenoceptor antagonism, or specific monoamine—oxidase type A inhibition. Examples include buspirone (3) (only... 

The involvement of serotonin (5-hydroxytryptamine) in disease states has been recognized for several decades. Research on antagonists awaited the recent development of methodology involving serotonin receptors. A thiazolopyrimidone serves as the nucleus for a pair of serotonin antagonists. The key intermediate 118 is in fact simply the lactonized form of 2-hydroxyethyl acetoace-tate. Condensation of this P-keto ester can be visualized to involve initial attack on the reactive... 

Anxiolytics are drugs used for the treatment of anxiety disorders. Apart from benzodiazpines, a frequently used anxiolytic is the 5HT1A (serotonin) receptor agonist buspiron, which has no sedative, amnestic or muscle-relaxant side effects, but whose action takes about a week to develop. Furthermore, it is less efficaceous than the benzodiazepines. Buspiron s mechanism of action is not fully understood. 

Hoyer D, Clarke DE, Fozard JR et al (1994) International Union of Pharmacology classification of receptors for 5-hydroxytryptamine (Serotonin). Pharmacol Rev 46 157-204... 

The AMPA receptors for glutamate, the nicotinic acetylcholine receptor and the 5-HT3-receptor for serotonin are cation channels (Table 1). When they open, the major consequence is a sudden entry of Na+, depolarization and an excitatory postsynaptic potential (EPSP Fig. 1). 

The GABAB-receptors, the muscarinic M2- and IVU-receptors for acetylcholine, the dopamine D2-, D3-and D4-receptors, the a2-adrenoceptors for noradrenaline, the 5-HTiA F-receptors for serotonin, and the opioid p-, 8- and K-receptors couple to G proteins of the Gi/o family and thereby lower [1] the cytoplasmic level of the second messenger cyclic AMP and [2] the open probability ofN- andP/Q-type Ca2+ channels (Table 1). The muscarinic Mr, M3- and M5-receptors for acetylcholine and the ai-adrenoceptors for noradrenaline couple to G proteins of the Gq/11 family and thereby increase the cytoplasmic levels of the second messengers inositol trisphosphate and diacylglycerol (Table 1). The dopamine Dr and D5-receptors and the (3-adrenoceptors for noradrenaline, finally, couple to Gs and thereby increase the cytoplasmic level of cyclic AMP. 

HT3 receptor. 5-Hydroxytryptamine receptor a receptor for serotonin (a neurotransmitter), which activates a variety of second messenger signaling systems and through them indirectly regulates the function of ion channels. 

IsmaielAM et al. (1997) 2-(l-Naphthyloxy)ethylamines with enhanced affinity for human 5-HTlD beta (h5-HTlB) serotonin receptors. J Med Chem 40(26) 4415-4419... 

In earlier proposals (Anderson et al. 1978), based on this stereoselectivity for the S enantiomer of MDMA, it was suggested that, rather than having a direct effect at serotonin receptors, perhaps MDMA was a neurotransmitterreleasing agent, acting in a fashion similar to amphetamine, for which the S enantiomer is also more active than the R enantiomer. A subsequent study... 

Although initial studies indicated that the various derivatives of 2,5-DMA exhibited low affinity for 5-HTi serotonin receptors (Shannon et al. 1984). it was unclear from these studies what the affinities of the drugs were for the respective subtypes of 5-HTjserotonin sites (i.e., 5-HTia, 5-HTjb, and 5-HTic receptors). In subsequent studies (Titeler et al. 1988), the affinities... 

FIGURE 2. Competition curves of R(-)-DOI for [ HJketanserin binding to 5-HT2 serotonin receptors in rat frontal cortex membranes in the presence and absence of the guanine nucleotide analog Gpp(NH)p... 

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