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)

Radioligand binding studies were performed to characterize serotonin 5HT1D binding sites in porcine and bovine brain. 3H-5HT binding, in the presence of 1 microM (+/-)pindolol (to block 5HT1A and 5HT1B receptors) and 100 nM mesulergine (to block 5HT1C receptors), was specific, saturable, and of high affinity. In porcine and bovine cortex and striatum the majority of 5HT1 sites (80%-90%) were of the 5HT1D subtype. In competition experiments 8-OH-DPAT, TFMPP, mesulergine, DOB, and ICS 205-930 had low affinity for 3H-5HT-labeled 5HT1D sites, indicating that the pharmacology of the 5HT1D site is distinct from previously identified 5HT1A, 5HT1B, 5HT1C, 5HT2, and 5HT3 sites. Guanyl nucleotides, GTPgammaS, and Gpp(NH)p, and divalent cations potently modulated the binding of 3H-5HT to 5HT1D sites in porcine and bovine striatum. Mg++ ions increased the number and affinity of 3H-5HT-labeled 5HT1D sites, while guanyl nucleotides decreased the number of 3H-5HT-labeled 5HT1D sites. These results demonstrate the presence of the 5HT1D receptors in porcine striatum and bovine cortex and provide direct demonstration that the radioligand binding assay for the 5HT1D receptor can monitor the interaction of this receptor with a GTP-binding protein.
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PMID:Detection and characterization of a 5HT1D serotonin receptor-GTP binding protein interaction in porcine and bovine brain. 252 22

5-Hydroxytryptamine (5-HT) is a mitogen for selected cell types. We have reported that 5-HT is an autocrine growth factor for functioning human pancreatic carcinoid (BON) cells; autocrine growth effect is transmitted by 5-HT1A but not 5-HT1C/2 receptors, activation of which decreases cyclic AMP production through a pertussis toxin-sensitive inhibitory GTP-binding protein. In this study, the effect of 5-HT3 receptor antagonist, ondansetron, on BON was examined. Ondansetron did not affect growth of BON cells and also affected neither stimulation of phosphatidylinositol hydrolysis or inhibition of cyclic AMP production evoked by 5-HT in BON cells. Ondansetron, however, inhibited mobilization of intracellular calcium evoked by 5-HT. Present findings suggest that BON cells possess 5-HT3 receptors, but their roles in pancreatic carcinoid cells are still unknown.
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PMID:Effect of 5-HT3 receptor antagonist (ondansetron) on functioning human pancreatic carcinoid cells. 825 12

Serotonin (5-HT) is considered to play a significant role in anxiety-related behaviors in animals through actions on the amygdaloid complex. To evaluate this role from the point of neurotransmitter release regulation, nystatin-perforated patch recording was employed on mechanically dissociated basolateral amygdala neurons containing functional synaptic boutons. GABAAergic miniature inhibitory postsynaptic currents (mIPSCs) were pharmacologically separated. In subsets of neurons, 8-OH-DPAT (1 microM), a specific 5-HT1A agonist, continuously inhibited mIPSC frequency without effects on mIPSC amplitude. By comparison, mCPBG (1 microM), a specific 5-HT3 agonist, transiently facilitated mIPSC frequency without effects on mIPSC amplitude. Together these results suggest the presynaptic existence of both 5-HT receptor subtypes. In these neurons, application of 8-OH-DPAT and its subsequent removal still suppressed mCPBG-induced responses on mIPSCs. This suppression was not caused by a reduction of presynaptic 5-HT3 receptor affinities to mCPBG and was completely eliminated by pretreatment with N-ethylmaleimide, a pertussis toxin sensitive GTP-binding protein inhibitor. In the neurons exhibiting presynaptic modulation with mCPBG but not 8-OH-DPAT, such suppression by exposure to 8-OH-DPAT was not observed. In conclusion, activation of presynaptic 5-HT1A receptors inhibited mIPSC frequency and at the same time suppressed, via a G-protein-mediated mechanism, the transient facilitation of mIPSC frequency produced by activation of presynaptic 5-HT3 receptors.
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PMID:Role of presynaptic 5-HT1A and 5-HT3 receptors in modulation of synaptic GABA transmission in dissociated rat basolateral amygdala neurons. 1246 78