Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P08908 (5-HT1A)
 5,574 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Earlier studies have indicated that the sympathoadrenal system and the corticotropic axis control brain levels of tryptophan (Trp), the precursor of 5-hydroxytryptamine (5-HT). We investigated the effects of 5-HT receptor agonists known to activate the sympathoadrenal system and/or the corticotropic axis on plasma and brain Trp levels. Neither the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, 0.5 mg/kg s.c.), nor the 5-HT1C receptor agonist 1-(3-chlorophenyl)piperazine (mCPP, 2.5 mg/kg s.c.) affected plasma and brain Trp levels. The 5-HT2 receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)2-aminopropane (DOI, 0.5-2 mg/kg s.c.) increased brain Trp levels, an effect which was significant for the two highest doses used (1.5-2 mg/kg s.c.).
 ...
PMID:The 5-HT2 receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)2-aminopropane increases brain tryptophan levels in the rat. 153 38

Eleven subtypes of central 5-HT receptor have so far been postulated, four of which have been cloned (5-HT1A, 5-HT1C, 5-HT1D and 5-HT2) and a fifth (the 5-HT3 receptor) purified. The present review discusses the agonists and antagonists which act at these subtypes with respect to their degree of selectivity and in vivo potency. Selective agonists exist for the 5-HT1A, 5-HT1B and 5-HT3 receptors and selective antagonists for the 5-HT2 and 5-HT3 receptors.
 ...
PMID:Centrally active 5-HT receptor agonists and antagonists. 155 8

In the presence of spiperone to block the 5-HT1A-mediated inhibition of pyramidal cell activity, 5-hydroxytryptamine (serotonin, 5-HT) produces a rapid transient increase in amplitude of the extracellularly recorded population spike from area CA1 of the hippocampus. Intracellular recording techniques in area CA1 of rat hippocampal slices were used to identify the ionic mechanism and to characterize the 5-HT receptor mediating this excitatory response to 5-HT. Most of the experiments were conducted in the presence of spiperone to block the 5HT1A hyperpolarization. Since spiperone also has high affinity for 5-HT2 receptors, any response mediated by 5-HT2 receptors would also be blocked. Bath perfusion of the slice with 5-HT increased the rectification of pyramidal cells in the subthreshold region, increased the resistance, and increased the amplitude of subthreshold excitatory postsynaptic potentials (EPSPs) to initiate spike firing. The 5-HT2,1C-selective agonist DOI mimicked this effect of 5-HT, and the 5-HT2,1C antagonist ketanserin (1 microM) blocked the effect of DOI. There was no change in the amplitude of the slow afterhyperpolarization (sAHP) or the amplitude of evoked inhibitory postsynaptic potentials (IPSPs). The increase in rectification and EPSP amplitude by 5-HT occurred even in the presence of the 5-HT4-selective antagonist BRL 24924 to prevent the decrease in amplitude of the sAHP by 5-HT. We conclude that 5-HT produces a fast excitatory response by increasing subthreshold conductance in CA1 hippocampal pyramidal cells. The identity of the receptor mediating this response was not conclusively identified, but resembled the 5-HT1C receptor.
 ...
PMID:5-Hydroxytryptamine increases excitability of CA1 hippocampal pyramidal cells. 158 62

To study possible interactions between dopamine (DA) and serotonin (5-HT) neurochemical systems in the D-1 supersensitized induction of oral activity in neonatal 6-hydroxydopamine (6-OHDA) lesioned rats, the effects of a series of 5-HT agonists and antagonists were determined. At 3 days after birth rats were treated with desipramine HCl (20 mg/kg i.p., base form, 1 hr) and 6-OHDA HBr (100 micrograms, salt form, in each lateral ventricle). Rats were observed individually as adults, once a minute every 10 min over a 1-hr period after challenge with a DA or 5-HT receptor agonist. The respective 5-HT1A and 5-HT1B agonists, (+/-)-8-hydroxydipropylaminotetralin (0.50 mg/kg s.c.) and CGS 12066B maleate (7-trifluoromethyl-4(4-methyl-1-piperazinyl)-pyrrolo[1, 2-alquinoxaline], 1:2 maleate salt; 3.0 mg/kg i.p.), did not increase oral activity. The mixed 5-HT1C and 5-HT2 receptor agonist, m-chlorophenylpiperazine (m-CPP), produced a slight increase in oral activity in control rats and a marked increase in oral activity in 6-OHDA-lesioned rats. In the 6-OHDA group the peak effect of 76.5 +/- 4.1 oral movements occurred with an m-CPP 2-HCl dose of 4.0 mg/kg. Pindolol (1.0 mg/kg i.p.), ketanserin tartrate (5 mg/kg i.p.) and MDL-72222 (3-tropanyl-3,5-dichlorobenzoate; 10 mg/kg s.c.), antagonists with high affinity for 5-HT1A,1B, 5-HT2 and 5-HT3 receptors, respectively, did not attenuate m-CPP actions. However, mianserin HCl (1.0 mg/kg s.c.), an antagonist with high affinity for 5-HT1C and 5-HT2 receptors, attenuated the oral response to m-CPP.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Supersensitization of the oral response to SKF 38393 in neonatal 6-OHDA-lesioned rats is mediated through a serotonin system. 160 67

We report the cloning and expression of a novel 5-HT receptor gene from human genomic DNA. This clone, HGCR1, contains an apparently intronless open reading frame of 390 amino acids with the seven hydrophobic regions, typical of G-protein coupled receptors. The deduced amino acid sequence of HGCR1 is 39%, 55% and 87% identical to that for the human 5-HT1A, the human 5-HT1D and the rat 5-HT1B receptor, respectively. [3H]5-HT binding to transfected COS-7 cell membranes yields a pharmacological profile similar to that of 5-HT1B receptor. Thus these findings indicate the presence of 5-HT1B-type receptor in the human.
 ...
PMID:Cloning and expression of the human 5-HT1B-type receptor gene. 161 Mar 47

Buspirone (BUSP) is a serotonergic (5-HT) agonist with activity at the 5-HT1A receptor. The BUSP induced prolactin (PRL) response was examined in 10 patients with a DSM IIIR diagnosis of obsessive-compulsive disorder (OCD). The results were compared with PRL responses to BUSP found in 10 age and sex matched healthy controls. The results suggest that the 5-HT1A receptor dysfunction may not be involved in the pathophysiology of OCD. The authors review the literature and consider the hypothesis that in OCD a complex interaction of other 5-HT receptor sub-types may be occurring, possibly with dysfunction primarily of the 5-HT2 receptors.
 ...
PMID:Buspirone induced prolactin responses in obsessive-compulsive disorder (OCD): is OCD a 5-HT2 receptor disorder? 162 56

Exposure of bovine adrenal chromaffin cells to ethanol [50 mM], alprazolam [10(-7) M] and buspirone [10(-7) M] inhibited basal and carbachol-induced release of catecholamines from these cells. The inhibition produced by alprazolam was prevented, and that produced by ethanol inhibited, by the presence of the benzodiazepine receptor antagonist, flumazenil [10(-8) M]. The inhibition produced by buspirone was unaffected by flumazenil, but was mimicked by the selective 5-HT1A receptor agonist, 8-OH DPAT and prevented by the 5-HT receptor antagonist spiperone [10(-6) M]. These results suggest that bovine adrenal chromaffin cells express GABAA receptors, containing a benzodiazepine recognition site and also 5-HT1A receptors. Ethanol and alprazolam appear to inhibit the excitability of bovine adrenal chromaffin cells by an action related to the former, while buspirone probably inhibits these cells through the latter. Maintaining bovine adrenal chromaffin cells for several days in culture medium, containing inhibitory concentrations of ethanol alprazolam or buspirone, produced a marked increase in binding sites for a [3H]dihydropyridine [DHP] calcium channel antagonist, on cell membranes. The increase in binding sites produced by alprazolam was greater than that produced by the other two agents and was almost completely prevented by the concomitant presence of flumazenil. The effects of ethanol and buspirone on the binding of DHP were not prevented by flumazenil. The results suggest that drugs which decrease excitability of bovine adrenal chromaffin cells by different mechanisms, may evoke a similar adaptive response involving an increase in DHP-sensitive calcium channels.
 ...
PMID:Chronic exposure to anxiolytic drugs, working by different mechanisms causes up-regulation of dihydropyridine binding sites on cultured bovine adrenal chromaffin cells. 167 64

The level of cyclic AMP in NCB-20 cells was increased by serotonin (5-HT), 5-methoxytryptamine and 2-methyl-5-HT with EC50 of 0.5 +/- 0.1, 1.0 +/- 0.1, 10 +/- 0.1 microM, respectively. The 5-HT-mediated increase of cyclic AMP content was completely blocked by metergoline but unaffected by 5-HT3 antagonists, ICS 205-930, MDL 72222, quipazine and 5-HT2 antagonist, ketanserin. Putative 5-HT1A agonists (8-OH-DPAT, ipsapirone, and buspirone) and 5-HT1B agonists (TFMPP and m-CPP) affected neither basal nor forskolin-dependent cyclic AMP accumulation. Receptor binding studies suggest that NCB-20 cells are devoid of 5-HT1A and 5-HT1B receptor sites. Application of 5-HT onto NCB-20 cells resulted in membrane depolarization by an evoked inward current which displayed rapid desensitization. 5-HT-mediated current had a reversal potential around 0 mV and was potently and reversibly inhibited by ICS 205-930. Our data suggest that in NCB-20 cells the 5-HT3 receptor is involved in the generation of inward currents, while the 5-HT receptor coupled to adenylate cyclase does not seem to correspond to any of the known receptor subtypes.
 ...
PMID:Characterization of two distinct 5-HT receptors coupled to adenylate cyclase activation and ion current generation in NCB-20 cells. 168 72

The somatodendritic 5-HT1A autoreceptor regulating 5-HT neuronal activity is currently poorly defined pharmacologically because there are no specific antagonists, but also because potent and stereoselective agonists are scarce. Moreover, there have been few, if any, attempts to specifically investigate structure-activity relationships for agonists acting at this site. Employing brain microdialysis techniques, we have examined the effects of the enantiomers of cis-8-hydroxy-1-methyl-2-(di-n-propylamino)tetralin (ALK-3; 0.01-0.3 mg/kg s.c.), its trans-1-methyl analogue (ALK-4; 0.3 mg/kg s.c.) and the pure enantiomers of the parent compound--8-OH-DPAT (0.3 mg/kg s.c.)--in an attempt to address stereochemical agonist structure-activity requirements of 5-HT release-controlling 5-HT1A autoreceptors in brain. The cis-1-methylated 8-OH-DPAT analogue (+)ALK-3 was comparable to the parent compound in reducing the 5-HT output from rat ventral hippocampus. In comparison, both (-)ALK-3 and the racemic trans-diastereomer to ALK-3, ALK-4, were inactive, while the two stereoisomers of 8-OH-DPAT strongly reduced 5-HT release. Pretreatment with (-)pindolol (8 mg/kg s.c.), which has high affinity for 5-HT1A radioligand binding sites, blocked the reduction of hippocampal 5-HT release induced by a submaximally effective dose of (+)ALK-3. The direct intrahippocampal administration of (+)ALK-3 (10 microM) via the perfusion medium did not affect 5-HT output. In summary, the data indicate that (+)ALK-3, like 8-OH-DPAT, is a very potent 5-HT receptor agonist which inhibits terminal 5-HT release in rat hippocampus, probably via activation of somatodendritic 5-HT1A autoreceptors.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:cis-(+)-8-OH-1-CH3-DPAT, (+)ALK-3, a novel stereoselective pharmacological probe for characterizing 5-HT release-controlling 5-HT1A autoreceptors. An in vivo brain microdialysis study. 169 73

In addition to the motor events associated with high pressure neurologic syndrome (HPNS), we have observed behavioral changes that resemble the 5-hydroxytryptamine (5-HT) syndrome in free-moving rats exposed to pressures up to 70 ATA. These include a flat body posture, head weaving, reciprocal forepaw treading, and hyperlocomotion. Such changes occur when brain 5-HT levels are raised or when 5-HT receptors are activated. We have therefore studied the behavior of rats at pressure treated either with saline or with one of the following drugs: p-chlorophenylalanine (pCPA) which depletes brain 5-HT by 85-90%, Wy 27587 which inhibits 5-HT reuptake, 5-hydroxytryptophan (5-HTP) and carbidopa which increase brain 5-HT synthesis, and quipazine which is a 5-HT receptor-agonist. After treatment, rats were individually exposed to pressure, and behavioral scores were made for 5 min every 10 ATA up to 70 ATA by an unbiased observer who was not aware of the treatment given. Analysis of all control rats indicated that only a flat body posture, forepaw treading, and hyperlocomotion were positively correlated with pressure, and these events were used in all subsequent analysis. Rats treated with pCPA with whole brain 5-HT levels reduced by 90% had scores significantly less than controls. Rats treated with Wy 27587 showed significantly increased scores. Rats treated with 5-HTP and quipazine failed to show a significant increase in scores. These results suggest that a modified form of the 5-HT syndrome occurs when rats are exposed to increased pressure, and the behavioral events seen are consistent with some activation of the 5-HT1A receptor subtype.
 ...
PMID:Exposure to high pressure may produce the 5-HT behavioral syndrome in rats. 169 8


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>