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Query: UNIPROT:P08908 (
5-HT1A
)
5,574
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Left kidneys obtained from male Wistar rats were perfused with Tyrode solution; the perfusion pressure was measured continuously and taken as an index of vascular resistance in the kidneys. 5-Hydroxytryptamine (5-HT; 3-50 nmol) caused dose-dependent dilator responses in kidneys preconstricted with noradrenaline (0.6 microM) and pretreated with ritanserin (10 nM) and ICS 205930 (10 nM). The 5-HT1 agonist 5-carboxamidotryptamine (5-CT; 16-64 nmol) also caused renal dilatations under similar conditions. The dilator responses to both 5-HT and 5-CT were antagonized by the non-selective 5-HT receptor antagonist metergoline (0.2 microM) and by the selective
5-HT1A
receptor antagonist BMY 7378 (0.4 microM). The guanylate cyclase inhibitor methylene blue (30 microM) and the nitric oxide (NO) synthase inhibitor nitro-L-
arginine
(L-NNA; 100 microM) significantly attenuated the dilator responses to 5-HT and 5-CT. The
5-HT1A
agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.5-16 nmol) also caused dose-dependent dilator responses in preconstricted rat kidneys. These responses were antagonized by metergoline and BMY 7378 and significantly attenuated by the NO inhibitors hemoglobin (10 microM) and L-NNA. The renal dilator responses noted with the beta-adrenoceptor blocker tertatolol (1-32 nmol) were also antagonized by metergoline and BMY 7378 and significantly reduced by L-NNA and hemoglobin. Both 8-OH-DPAT and tertatolol (1-30 microM) significantly reduced the vasoconstrictor responses to angiotensin II (20 pmol). Our data indicate that 5-HT receptors located on the vascular endothelium of the renal circulation are involved in the dilator actions of 5-HT, 5-CT, 8-OH-DPAT and tertatolol, and suggest that these receptors resemble the
5-HT1A
subtype.
...
PMID:5-Hydroxytryptamine-induced vasodilatation in the isolated perfused rat kidney: are endothelial 5-HT1A receptors involved? 183 83
The vascular effects of serotonin (5-hydroxytryptamine, 5-HT) are complex and heterogeneous. In human forearm, we showed that low doses of 5-HT cause marked but transient vasodilatation followed by a persistent vasodilator response. In in vitro and in animal experiments, 5-HT induced release of nitric oxide (NO) through stimulation of endothelial 5-HT1-like receptors. In the present study, we investigated involvement of the "NO pathway" and possible involvement of the
5-HT1A
receptor subtype in 5-HT-induced persistent vasodilator response. In 8 healthy volunteers, we infused 5-HT (0.1, 0.3, and 1 ng/kg/min) and the selective
5-HT1A
receptor agonist flesinoxan (15, 45, and 150 ng/kg/min) intraarterially (i.a.) with NG-monomethyl-L-
arginine
(L-NMMA 30 micrograms/kg/min) or saline. Forearm blood flow (FBF) was measured by automated R-wave-triggered venous occlusion plethysmography. Forearm vascular resistance (FVR) was derived from simultaneously recorded i.a. blood pressure (BP) and FBF. 5-HT dose-dependently decreased FVR (p < 0.001). The persistent vasodilator response to 5-HT appears to be mediated by NO release, as suggested by its complete abolition by L-NMMA (p < 0.001). Flesinoxan decreased FVR slightly, but only at high doses (p < 0.05). The present findings indicate that
5-HT1A
receptors are not functionally involved in 5-HT-mediated vasodilatation in human forearm.
...
PMID:No functional involvement of 5-hydroxytryptamine1A receptors in nitric oxide-dependent dilatation caused by serotonin in the human forearm vascular bed. 752 2
In order to test the hypothesis that a 5-hydroxytryptamine (5-HT)-induced increase in vascular permeability results from a cascade triggered by activation of the synthesis of nitric oxide (NO), the vascular permeability was investigated using the Pontamine sky blue leakage method in male mice. Subcutaneous injection of 5-HT induced a dose-related increase of vascular permeability at the injection site. The vascular permeability induced by 5-HT was inhibited by pretreatment with intraperitoneal injection of ketanserin (5-HT2A antagonist) and methysergide (5-HT1/2A antagonist), less efficiently by 1-(2-methoxyphenyl)-4-[4-(2-phthalimido)butyl] piperazine (NAN-190) (
5-HT1A
antagonist), but not by granisetron (5-HT3 antagonist). Increase in vascular permeability induced by 5-HT was inhibited by concurrent intravenous administration of NO synthase inhibitors NG-nitro-L-
arginine
methyl ester (L-NAME) and methylene blue but not by the inactive enantiomer NG-nitro-D-
arginine
methyl ester (D-NAME). These results suggest that 5-HT increases vascular permeability by activating the 5-HT receptors and that endogenous NO is involved in this effect of 5-HT.
...
PMID:Possible role of nitric oxide in 5-hydroxytryptamine-induced increase in vascular permeability in mouse skin. 753 Dec 92
We studied the
5-HT1A
receptor gene in 50 mood disorders and 50 normal volunteers. The
5-HT1A
receptor gene was amplified by polymerase chain reaction and sequenced by the dideoxy method. The sequence of the
5-HT1A
receptor encodes a protein of 422 amino acids, that is, one amino acid longer than the reported sequence (Kobilka et al. 1987). The DNA sequence at positions 454 to 459 is CGC GCC GCT, not CCG CGT, and the amino acids sequence at these positions is changing from proline
arginine
to
arginine
alanine alanine. These differences, however, were observed in both mood disorders and controls. One silent polymorphism, CTG to GTA at position 294, was found. These results suggest that the
5-HT1A
receptor gene is intact in mood disorders.
...
PMID:The gene encoding the 5-HT1A receptor is intact in mood disorders. 761 60
The aim of the studies was to examine the mechanism of the renal vasodilator action of the beta-adrenoceptor antagonist tertatolol. In isolated Tyrode perfused rat kidneys, constricted with norepinephrine, serotonin (5-HT) or BaCl2, tertatolol evokes dilatations; these vasodilator responses are not due to an interaction of tertatolol with alpha- or beta-adrenoceptors, muscarinic or nicotinic receptors, opioid receptors, dopamine or histamine receptors and they are independent of prostaglandin release. In the presence of ritanserin and ICS 205930, to block 5-HT2 and 5-HT3 receptors, tertatolol, 5-HT, 5-carboxamidotryptamine (5-CT) and 8-hydroxy-2 (di-n-propylamino) tetralin (8-OH-DPAT) all evoked renal vasodilator responses that were significantly reduced by the nonselective 5-HT antagonist metergoline and by the selective
5-HT1A
antagonist BMY 7378 suggesting that 5-HT1 receptors resembling the
5-HT1A
subtype were involved. The nitric oxide (NO) inhibitors hemoglobin and nitro-L-
arginine
(L-NNA), as well as the guanylate cyclase inhibitor methylene blue also inhibited the vasodilator responses to tertatolol and to the serotonergic agonists, suggesting the involvement of the NO-cyclic GMP pathway. These data suggest that 5-HT receptors located on the vascular endothelium of the rat renal circulation are involved in the vasodilator responses caused by tertatolol and these receptors resemble the
5-HT1A
subtype.
...
PMID:Vasodilator effect of tertatolol in isolated perfused rat kidneys: involvement of endothelial 5-HT1A receptors. 790 15
1. This study was designed to examine further the attenuated contractile responses to 5-hydroxytryptamine (5-HT) previously observed in aortae from diabetic rats. 2. Cumulative concentration-response curves to 5-HT, and the 5-HT receptor agonists, alpha-methyl 5-HT (alpha-Me-5-HT, 5-HT2/1C agonist), (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2- aminopropane (DOI, 5-HT2/1C agonist) and 5-carboxamidotryptamine (5-CT,
5-HT1A
/1B/1D agonist), were examined in endothelium-intact and -denuded aortae from 2-week streptozotocin (STZ)-diabetic and control rats. 3. In endothelium-intact and -denuded aortae from diabetic rats, maximum responses to 5-HT and alpha-Me-5-HT were significantly reduced compared to those of aortae from control rats. Responses to these agonists were inhibited by the 5-HT2/1C receptor antagonist, ketanserin (0.1 microM). 4. The attenuated responses to 5-HT of aortae from diabetic rats were normalized by chronic insulin treatment of the rats (5 units day-1, s.c.), but not by altering the glucose concentration of the bathing fluid. 5. The nitric oxide synthase inhibitor N-nitro-L-
arginine
(NOLA, 0.1 mM) significantly potentiated responses to both 5-HT and alpha-Me-5-HT in endothelium-intact aortae. However, the difference between maximum responses of aortae from diabetic and control rats was still evident in the presence of NOLA. 6. Endothelium-intact rings, in the presence of ketanserin (0.1 microM) and preconstricted with the thromboxane A2-mimetic, U46619 (0.1-0.3 microM), from control and diabetic rats, did not relax to cumulative additions of 5-HT (1 nM-30 microM). 7. Contractile responses to DOI were obtained only in endothelium-denuded aortae, and in endothelium-intact aortae in the presence of NOLA, from control rats.8. Contractile responses to 5-CT were obtained only in endothelium-denuded aortae from both control and diabetic rats, and in endothelium-intact aortae in the presence of NOLA, from control rats.9. [3H]-ketanserin binding studies showed that there was no significant change in the affinity or density of [3H]-ketanserin for binding sites in membrane preparations of aortae from control and diabetic rats.10. These results suggest that 5-HT contracts aortae from rats via 5-HT2/1c receptor activation.However, the simultaneous release of EDRF from endothelial cells in response to 5-HT does not appear to be receptor-mediated. The attenuated contractile responses observed to 5-HT in aortae from 2-week diabetic rats do not appear to be mediated by changes in either endothelial cell function or an alteration in 5-HT receptor affinity or density.
...
PMID:Attenuated 5-hydroxytryptamine receptor-mediated responses in aortae from streptozotocin-induced diabetic rats. 801 21
The effect of serotonin [5-hydroxytryptamine (5-HT)] on pial venous tone of the pig was examined using in vitro tissue bath techniques. Isolated pial venous rings exhibited spontaneous rhythmic contractions (SRC) on mechanical stretching and/or applications of several vasoactive substances, including norepinephrine. On the other hand, KCl induced sustained active muscle tone (SAT) without SRC. The SRC induced by mechanical stretching were not affected by tetrodotoxin, nitro-L-
arginine
, alpha- and beta-adrenergic, histaminergic, and muscarinic receptor antagonists, indicating that the SRC in porcine pial veins are of myogenic origin. The SRC induced by stretching or applications of vasoactive substances and SAT induced by KCl were inhibited by 5-HT in a concentration-dependent manner. The inhibition was prevented by methysergide and methiothepin but not by ketanserin, propranolol, 3 alpha-tropanyl-1H-indole-3-carboxylic acid ester, hemoglobin, or nitro-L-
arginine
. The SRC and SAT were inhibited by 5-carboxamidotryptamine (5-CT), 8-hydroxy-2-di-N-propylaminotetralin HBr (8-OHDPAT), 1-[3-(trifluoromethyl)phenyl]piperazine (TFMPP), and 5-methoxytryptamine (5-MT), but not by sumatriptan, alpha-methylserotonin, or 2-methylserotonin. On the other hand, 5-CT, 8-OHDPAT, TFMPP, 5-MT, and sumatriptan constricted the porcine pial arteries exclusively. In 15% of pial venous preparations examined, 5-HT at low concentrations induced ketanserin-sensitive constrictions. These results indicate that the porcine pial venous smooth muscle contains multiple subtypes of 5-HT receptors. The 5-HT inhibition of SRC and SAT is predominant and is mediated by 5-HT1-like receptors, which, however, do not seem to correspond to
5-HT1A
, 5-HT1B, 5-HT1C, 5-HT1D, 5-HT1E, or 5-HT1F receptor subtypes.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Serotonin relaxes porcine pial veins. 816 Aug 3
5-hydroxytryptamine (5-HT) has been reported to show some effects in respiratory tissues by activation of different subtype receptors. It has been demonstrated that 5-HT2 receptor activation causes in vivo and in vitro airways contraction and enhances effects of cholinergic nerve-mediated responses, whereas 5-HT1 receptor activation seems to be related to a relaxant effect. Moreover, in isolated guinea pig ascendens colon preparations 5-HT1 activation causes relaxation by involvement of nitric oxide (NO). The aim of this study was to investigate the effects of 5-HT1 receptor activation in guinea pig trachea as well as NO probable role in this activation. In tissues pretreated with both ketanserin (10 microM), an antagonist of 5-HT2 receptors, and ondansetron (10 microM), an antagonist of 5-HT3 receptors, 5-HT (from 10 nM to 10 mM) relaxed guinea pig trachea precontracted with acetylcholine (ACh, 100 microM). Carboxamidotryptamine (5-CT, from 10 nM to 10 mM), an agonist of 5-HT1 receptors, as well relaxed guinea pig trachea precontracted with ACh (100 microM). A pretreatment with NAN-190 (from 10 nM to 100 microM), a
5-HT1A
selective antagonist, reduced the 5-HT and 5-CT relaxant effects but only at very high concentrations. Finally, a pretreatment with L-nitro-
arginine
-methyl-ester (L-NAME, 1 mM), an inhibitor of NO-synthase, and L-
arginine
(L-
ARG
, 1 mM), a precursor of NO synthesis, did not modify 5-HT and 5-CT responses in guinea pig trachea. In conclusion, this study suggests a 5-HT relaxant activity in guinea pig trachea via a 5-HT1 receptor activation without any NO pathway involvement. However, further investigations are needed to clarify which 5-HT1 receptor subtype is involved in 5-HT relaxant effect.
...
PMID:Effects of in vitro 5-HT1 receptor activation in guinea pig trachea. 869 22
Stimulation of glutamatergic NMDA receptor in adult rat hippocampal synaptoneurosomes induces statistically significant Ca(2+)-dependent liberation of arachidonic acid (AA) and nitric oxide (NO)-activated cGMP synthesis. NMDA acting for 5 min at 100 microM markedly increases, by approx. 25%, Ca(2+)-mediated AA release from phospholipids of hippocampal synaptoneurosomes. Prolonged stimulation of NMDA receptor up to 10 min has smaller stimulatory effect and enhances AA release by about 6%. Moreover, NMDA activates NO-dependent cGMP production by approx. 5 times more than the Ca2+ itself. Release of both these second messengers is completely blocked by the competitive NMDA antagonist, APV (100 microM). The NMDA-mediated cGMP elevation completely depends on NO action, and is abolished by the specific inhibitor of NO synthase, NG-nitro-L-
arginine
. Moreover, serotonin at 10 microM in the presence of 10 microM pargyline, potently decreases both Ca(2+)- and NMDA receptor-mediated AA and cGMP release in hippocampal synaptoneurosomes. The agonist of
5-HT1A
receptor, buspirone, in a way similar to serotonin itself, counteracts the Ca(2+)- and also NMDA receptor-evoked AA release and cGMP accumulation. An antagonist of
5-HT1A
receptor, NAN-190, eliminates the effect of serotonin and buspirone on AA and NO/cGMP liberation. An antagonist of serotonergic 5-HT2 receptor, ketanserin, has no effect on the Ca2+ and serotonin action. These results indicate that serotonin, through
5-HT1A
receptor, potently antagonizes the action of excitatory amino acid for AA release and NO/cGMP synthesis in the adult rat hippocampus. In conclusion, the interaction of serotonin with the glutamatergic system in the hippocampus may play an important role in the modulation of a signal transduction pathway, and by this molecular mechanism serotonin may exert a neuroprotective effect on hippocampal neurons.
...
PMID:Activation of serotonergic 5-HT1A receptor reduces Ca(2+)- and glutamatergic receptor-evoked arachidonic acid and No/cGMP release in adult hippocampus. 874 Apr 52
We investigated nitric oxide (NO) involvement in the hyperphagia induced by the
5-HT1A
receptor agonist 8-hydroxy-2-di-n-(propylamino)tetralin (8-OH-DPAT). A NO synthase inhibitor, NG-nitro-L-
arginine
methyl ester (L-NAME), dose dependently inhibited 8-OH-DPAT-induced eating in freely feeding rats. However, the inactive isomer D-NAME was without effect. The inhibitory effects of L-NAME on 8-OH-DPAT-induced hyperphagia were reversed by simultaneous administration of L-
arginine
. These results suggest that NO participates in the 8-OH-DPAT-induced hyperphagia which is elicited by activation of the
5-HT1A
receptor.
...
PMID:Effects of a nitric oxide synthase inhibitor on 5-HT1A receptor agonist 8-OH-DPAT-induced hyperphagia in rats. 898 45
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