Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P46098 (5-HT3 receptor)
 2,290 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

5-HT3 receptors have an exclusive neuronal location and evidence is presented of their involvement in behaviour. 5-HT3 receptor antagonists such as ondansetron, tropisetron and zacopride have provided the critical pharmacological tools to reveal a potent and efficacious ability to regulate disturbed behaviour. Thus the 5-HT3 receptor antagonists will restore to normal rodent and primate behaviour disturbed by increasing limbic dopamine function, aversive situations, cognitive impairments and drug abuse. The remarkable feature of their action is a failure to modify normal behaviour. This unique pharmacological signature has ensured a wide interest in the potential role of the 5-HT3 receptor antagonists in the treatment of schizophrenia, anxiety, age related memory impairment and the problems of withdrawal from drugs of abuse. The preclinical data and preliminary clinical observations are presented.
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PMID:Astra Award Lecture. The psychopharmacology of 5-HT3 receptors. 136 67

Latent inhibition (LI) is a behavioral model of selective attention that has been used to study the attentional deficits seen in schizophrenia. In the present study, we examined the effect of 5-hydroxytryptamine3 (5-HT3) receptor blockade on LI using the conditioned emotional response (CER) procedure. Prior exposure to 20, 30, or 40 stimulus presentations significantly, and almost completely, inhibited the CER to that stimulus. This LI effect was much weaker when only 10 preexposures were given. 1H-indole-3-carboxylic acid, trans-octahydro-3-oxo-2,6-methano-2H-quinolizin-8-yl ester methanesulfonate (MDL 73,147EF), a selective 5-HT3 receptor antagonist, significantly facilitated the LI effect observed after 10 preexposures at 0.1 mg/kg but not at 0.01 mg/kg. The magnitude of this effect was comparable to that observed with the classical neuroleptic haloperidol (0.1 mg/kg). Neither MDL 73,147EF nor haloperidol affected the CER in animals not preexposed to the stimulus. These results strongly corroborate suggestions that 5-HT3 receptor antagonists will be of use in the treatment of schizophrenia.
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PMID:MDL 73,147EF, a 5-HT3 antagonist, facilitates latent inhibition in the rat. 140 84

Evidence is reviewed that 5-HT (5-hydroxytryptamine, serotonin) acting through the 5-HT3 receptor subtype can influence behaviour relevant to anxiety, schizophrenia and cognitive disorders, and that 5-HT3 receptor antagonists such as ondansetron (CAS 116002-70-1) can correct behavioural disturbance in the absence of effect on normal behaviour. The 5-HT3 receptor antagonists exert a breadth of action over a wide dose range in rodent and primate models to inhibit aversive behaviour in animal models of anxiety and certain symptoms of withdrawal from drugs of abuse, alcohol, nicotine, diazepam and cocaine, to antagonise increased locomotor activity caused by mesolimbic dopamine excess, and facilitate performance in cognitive tests. The studies reveal an important role for 5-HT3 receptors in the regulation of limbic-cortical functioning, and a critical role for 5-HT3 receptor antagonists to establish the role of 5-HT3 receptors in schizophrenia, anxiety, drug withdrawal phenomena and cognitive disturbance. Preliminary clinical trials indicate a positive effect of ondansetron in anxiety, schizophrenia, alcohol withdrawal and age associated memory impairment.
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PMID:Serotonin and psychiatric disorders. A key to new therapeutic approaches. 158 95

It is no longer tenable to attribute all the antipsychotic action of antipsychotic drugs to dopamine (DA) D2 receptor blockade and subsequent development of depolarization inactivation of the mesolimbic or mesocortical DA neurons. The chief evidence for this position is that clozapine (CLOZ) does not differ from typical antipsychotic drugs in these regards but is more effective than typical neuroleptic drugs. The mechanism of action of atypical antipsychotic drugs related to CLOZ may involve reduction of dopaminergic activity in the mesolimbic system by a variety of mechanisms, including D1 and D2 receptor blockade. Relatively higher affinity for the serotonin (5HT)2 receptor than for the D2 receptor may also be important to the action of CLOZ-like compounds. Enhanced DA release in the mesocortical system may be relevant to the effectiveness of these agents in treating negative symptoms. Several other classes of new agents alter the dopaminergic system by means of alternative mechanisms. Partial DA agonists may modulate DA neurotransmission more adequately than pure antagonists by producing a mix of direct agonist and antagonistic effects. DA autoreceptor agonists and 5HT3 antagonists appear to act by diminishing the release of DA from some, but not all, DA neurons. Substituted benzamides are "pure" D2 antagonists with some in vivo selectivity for limbic D2 over striatal D2 receptors. Highly selective D1 antagonists have been proposed to produce equivalent antipsychotic activity and fewer extrapyramidal symptoms than D2 antagonists. Antagonists of the recently identified D3 receptors are being sought. Excessive stimulation of the N-methyl-D-aspartate (NMDA) subtype of the glutamate receptor, leading to neurotoxicity or diminished activation of this receptor, is the target of novel approaches to treating schizophrenia. Phencyclidine (PCP) antagonists that would activate the NMDA receptor and sigma receptor antagonists are of interest as antipsychotic agents. Therapeutic strategies for treating schizophrenia, schizophrenia-related disorders, and other psychoses will likely be genuinely diverse in the next decade.
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PMID:The mechanism of action of novel antipsychotic drugs. 167 53

Compared to traditional neuroleptics, most of the new antipsychotics are characterized by a low extrapyramidal side effect (EPS) liability and varying antipsychotic efficacy. This topic is reviewed for four principal classes of new, established, and potential antipsychotics: (1) Antipsychotics such as sulpiride and remoxipride that block a subgroup of dopamine (DA) D2/D3 receptors produce a relatively low level of side effects, including EPS, and have an antipsychotic effect equal to or slightly weaker than traditional neuroleptics. D1 antagonists demonstrate a low level of EPS in primates and may prove to be a valuable new type of antipsychotic drug. (2) Theoretically, partial D2 agonists have the advantage of producing few or no EPS and a specific beneficial effect in negative symptoms, but as yet the expectations have not been fulfilled. (3) Nondopamine drugs such as serotonin (5HT1) agonists, 5HT2 antagonists, 5HT3 antagonists, and gamma-amino-butyric-acid-A (GABA-A) benzodiazepine agonists have anxiolytic, antidepressant, antiaggressive, and maybe antiparkinsonian effects and may play an adjunctive role in the treatment of schizophrenia. 5HT3 antagonists (e.g., ondansetron), partial benzodiazepine agonists, and partial glutamate agonists may prove to be effective antipsychotics. (4) Antipsychotics such as clozapine and risperidone, which affect D2/D3 receptors as well as 5HT, alpha 1, and/or D1 receptors appear to have the most pronounced antipsychotic effect.
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PMID:New antipsychotics: classification, efficacy, and adverse effects. 171 8

Antagonists of 5HT3 receptors are clinically effective in treating nausea and emesis associated with certain oncolytic drugs, including cisplatin. Moreover, these agents may be useful in pharmacological management of several central nervous system disorders, including anxiety, schizophrenia, dementia, and substance abuse. Our studies on aroyltropanamides led to the discovery that dihydrobenzofuranyl esters and amides are potent 5HT3 receptor antagonists. Simple benzoyl derivatives of tropine and 3 alpha-aminotropane possessed weak 5HT3 receptor antagonist activity, as judged by blockade of bradycardia produced by iv injection of serotonin (5HT) to anesthetized rats. Within this series, use of benzofuran-7-carboxamide as the aroyl moiety led to a substantial increase of 5HT3 receptor affinity. The optimal 5HT3 receptor antagonist identified via extensive SAR studies was endo-5-chloro-2,3-dihydro-2,2-dimethyl-N-(8-methyl-8-azabicyclo[3.2.1]oc t- 3-yl)-7-benzofurancarboxamide (Z)-2-butenedioate (zatosetron maleate). The 7-carbamyl regiochemistry, dimethyl substitution, chloro substituent, and endo stereochemistry were all crucial elements of the SAR. Zatosetron maleate was a potent antagonist of 5HT-induced bradycardia in rats (ED50 = 0.86 micrograms/kg i.v.). Low oral doses of zatosetron (30 micrograms/kg) produced long-lasting antagonism of 5HT3 receptors, as evidenced by blockade of 5HT-induced bradycardia for longer than 6 h in rats. Moreover, this compound did not produce hemodynamic effects after i.v. administration to rats, nor did it block carbamylcholine-induced bradycardia in doses that markedly blocked 5HT3 receptors. Thus, zatosetron is a potent, selective, orally effective 5HT3 receptor antagonist with a long duration of action in rats.
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PMID:Zatosetron, a potent, selective, and long-acting 5HT3 receptor antagonist: synthesis and structure-activity relationships. 173 48

Ligands of various chemical classes (e.g., indoles, indazoles, benzamides, carbazoles, and quinolines) have demonstrated high affinity for the 5-HT3 receptor in radiolabeled ligand-binding studies, and have shown 5-HT3 receptor antagonistic activity in functional assays which utilize the excitatory effects of 5-HT on enteric neurons and autonomic afferents. Several 5-HT3 antagonists are currently being evaluated for potential use in the treatment of migraine, schizophrenia, and anxiety, and a few have already demonstrated high efficacy as antiemetics in cancer chemotherapy. The purpose of this presentation is to highlight the significant structure-affinity relationships (SAFIR) and common geometrical features among 5-HT3 receptor ligands, and to describe the three-dimensional pharmacophore for the 5-HT3 recognition site derived from computational techniques. The chemical template containing the recognition elements (functional groups) for the 5-HT3 receptor are: an aromatic or heteroaromatic ring system, a coplanar carbonyl group, and a nitrogen center, interrelated by well-defined distances. Two "binding shapes" or "active shapes" for 5-HT3 ligands have been identified from detailed conformational analyses.
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PMID:Molecular modeling of 5-HT3 receptor ligands. 181 57

5-HT3 receptors or recognition sites have been located in the brain of many animal species and man, and are considered to mediate an increase in cation conductance. The functional relevance of the central 5-HT3 receptors is being established using selective 5-HT3 receptor antagonist ligands, which have been shown to modify behaviour in animal tests that is predictive of an action to reduce anxiety, schizophrenia and cognitive disorders. A remarkable feature of the effect of 5-HT3 receptor antagonists is their ability and potency to control a disturbed behaviour in the absence of effect on normal behaviour. This reveals an important role for 5-HT in different behaviours: indeed, the breadth of action of the 5-HT3 receptor antagonists may be indicative of the critical importance of 5-HT in the control of catecholaminergic, cholinergic and peptidergic systems throughout the forebrain. Precisely how such effects are achieved remains a significant investigative challenge, with the potential for novel therapeutic developments being a major goal.
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PMID:Pharmacological properties and functions of central 5-HT3 receptors. 184 Feb 28

The review presents evidence that 5-HT3 receptors within the brain may contribute to the control of behavior. 5-HT3 receptor antagonists GR38032F, zacopride, ICS 205-930 and other agents are very potent in reducing mesolimbic dopamine hyperactivity caused by the injection of amphetamine or infusion of dopamine into the rat nucleus accumbens and amygdala, and the ventral striatum of the marmoset. Such actions are distinguished from those of neuroleptic agents by a failure to reduce normal levels of activity or to induce a rebound hyperactivity after discontinuation of treatment. Indeed, the 5-HT3 receptor antagonists can prevent the neuroleptic-induced rebound hyperactivity. Further evidence that 5-HT3 receptors moderate limbic dopamine function is shown by their ability to reduce both the behavioral hyperactivity and changes in limbic dopamine metabolism caused by DiMe-C7 injection into the ventral tegmental area. The 5-HT3 receptor antagonists also have an anxiolytic profile in the social interaction test in the rat, the light/dark exploration test in the mouse, the marmoset human threat test and behavioral observations in the cynomolgus monkey. They differ from the benzodiazepines by an absence of effect in the rat water lick conflict test and a withdrawal syndrome. Importantly, the 5-HT3 receptor antagonists are highly effective to prevent the behavioral syndrome following withdrawal from treatment with diazepam, nicotine, cocaine and alcohol. Intracerebral injection techniques in the mouse indicate that the dorsal raphe nucleus and amygdala may be important sites of 5-HT3 receptor antagonist action to inhibit aversive behavior. Studies with GR38032F indicate an additional effect in reducing alcohol consumption in the marmoset. The identification and distribution of 5-HT3 receptors in the brain using a number of 5-HT3 receptor ligands, [3H]65630, [3H]zacopride and [3H]ICS 205-930 correlates between studies, and the 5-HT3 recognition sites in cortical, limbic and other areas meet the criteria for 5-HT3 receptors to mediate the above behavioral effects. Thus the use of 5-HT3 receptor antagonists reveals an important role for 5-hydroxytryptamine in the control of disturbed behavior in the absence of effect on normal behavior. The profile of action of the 5-HT3 receptor antagonists has generated a major clinical interest in their potential use for schizophrenia, anxiety and in the control of drug abuse.
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PMID:The psychopharmacology of 5-HT3 receptors. 220 69

It has been suggested that changes in brain 5-hydroxytryptamine3 receptor function may contribute to some behavior disorders, such as anxiety, schizophrenia and drug abuse. We are using the whole-cell version of the patch-clamp technique to study the function of 5-hydroxytryptamine3 channels in neurons freshly dissociated from rat nodose ganglion. In these cells, 5-hydroxytryptamine elicits an inward current over the concentration range of 0.25-100 microM (EC50 = 2.62 microM) by activating 5-hydroxytryptamine3 receptors. The muscarinic cholinergic antagonist atropine reduced the amplitude of 5-hydroxytryptamine activated inward current in a concentration-dependent manner. Other muscarinic antagonists, scopolamine, dexetimide, the M1 muscarinic receptor antagonist pirenzepine, the M2 receptor antagonist methoctramine and the M3 receptor antagonist 4-DAMP methiodide also inhibited 5-hydroxytryptamine-induced inward current. Atropine did not appear to change the reversal potential of this current. In the presence of 5 microM atropine, the concentration-response curve for 5-hydroxytryptamine current was shifted to the right in a parallel fashion. The EC50 value for 5-hydroxytryptamine was increased from 2.62 to 8.76 microM. Schild plots of increasing atropine and 5-hydroxytryptamine concentrations revealed a pA2 value of 5.74 for atropine (apparent KD = 1.8 microM). These observations suggest that atropine competitively antagonizes the activation of a receptor for the neurotransmitter serotonin, a novel action of muscarinic antagonists in the nervous system. This effect of atropine may contribute to the clinical symptoms seen in severe atropine intoxication.
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PMID:The effect of atropine on the activation of 5-hydroxytryptamine3 channels in rat nodose ganglion neurons. 753 5


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