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)

The study was conducted on a human (Jurkat) T cell line, loaded with a Na+ fluorescent probe, SBFI/AM. Serotonin and an agonist of 5-HT3 receptor-channels, 2-methyl-5HT, evoked Na+ influx, whereas the agonists of other serotonergic receptor subtypes, i.e., 5-HT1A and 5-HT1B receptors, failed to induce Na+ influx in these cells. By using 3H-BRL43694, an agonist of 5-HT3 receptor-channels, we characterized 5-HT3 lymphocyte receptors which exhibited a density (Bmax) of 300 +/- 20 fmol/10(6) cells and a Kd of 30 nM in Jurkat T cells. The T-cell 5-HT3 receptor-channel is not regulated either by the protein kinase C or by the free intracellular calcium concentrations as the agents known to activate the PKC and to induce increases in intracellular free calcium concentrations failed to influence the free intracellular Na+ concentrations, [Na+]i, in these cells. Furthermore, an increase in [Na+]i, induced by 2-methyl-5HT, via 5-HT3 receptor-channels seems to stimulate T-cell activation by facilitating the progression of T cells from S to G2/M phase of the cell cycle.
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PMID:5-HT3 receptor-channels coupled with Na+ influx in human T cells: role in T cell activation. 1049 77

Using whole-cell patch-clamp methods, we examined the hypothesis that serotonin [5-hydroxytryptamine (5-HT)] receptor activation enhances TRPV1 function in mouse colon sensory neurons in lumbosacral dorsal root ganglia, which were identified by retrograde labeling with DiI (1,1'-dioctadecyl-3,3,3',3-tetramethlindocarbocyanine methanesulfonate) injected into multiple sites in the wall of the descending colon. 5-HT increased membrane excitability at a temperature below body temperature in response to thermal ramp stimuli in colon sensory neurons from wild-type mice, but not from TRPV1 knock-out mice. 5-HT significantly enhanced capsaicin-, heat-, and proton-evoked currents with an EC50 value of 2.2 microm. 5-HT (1 microm) significantly increased capsaicin-evoked (100 nm) and proton-evoked (pH 5.5) currents 1.6- and 4.7-fold, respectively, and significantly decreased the threshold temperature for heat current activation from 42 to 38 degrees C. The enhancement of TRPV1 by 5-HT was significantly attenuated by selective 5-HT2 and 5-HT4 receptor antagonists, but not by a 5-HT3 receptor antagonist. In support, 5-HT2 and 5-HT4 receptor agonists mimicked the facilitating effects of 5-HT on TRPV1 function. Downstream signaling required G-protein activation and phosphorylation as intracellularly administered GDP-beta-S [guanosine 5'-O-(2-thiodiphosphate], protein kinase A inhibitors, and an A-kinase anchoring protein inhibitor significantly blocked serotonergic facilitation of TRPV1 function; 5-HT2 receptor-mediated facilitation was also inhibited by a PKC inhibitor. We conclude that the facilitation of TRPV1 by metabotropic 5-HT receptor activation may contribute to hypersensitivity of primary afferent neurons in irritable bowel syndrome patients.
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PMID:TRPV1 function in mouse colon sensory neurons is enhanced by metabotropic 5-hydroxytryptamine receptor activation. 1550 39

5-HT receptor subtypes are widely expressed in primary sensory neurons, yet so far little is known about the interaction among them. This study aimed to investigate whether the activation of 5-HT2 and 5-HT1 receptors could modulate 5-HT3 receptor mediated current in rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The majority of TG neurons examined responded to 5-HT (10(-7)-10(-3) M) with a fast activating and rapid desensitizing inward current (77.2%, 71/92). This 5-HT activated current (I(5-HT)) was blocked by ICS 205-930 and mimicked by 2-methyl-5-HT, indicating that it was mediated by 5-HT3 receptor. With alpha-methyl-5-HT applied prior to 5-HT application, I(5-HT) was potentiated in a concentration-dependent manner, with the maximal modulatory effect at 10(-9) M of alpha-methyl-5-HT. The concentration-response curve for I(5-HT) pretreated with alpha-methyl-5-HT shifts upwards compared with that for I(5-HT) without alpha-methyl-5-HT pretreatment, the maximal I(5-HT) value having increased by (60.3 +/- 5.7)% of its control while the EC50 values of the two curves being very close, i.e. (2.0 +/- 0.3) x 10(-5) M vs (1.7 +/- 0.2) x 10(-5) M, respectively. The alpha-methyl-5-HT potentiation of I(5-HT) was removed by intracellular dialysis of either GDP-beta-S, a non-hydrolyzable GDP analog, or GF109203X, a selective PKC inhibitor, almost completely. Preapplication of R-(+)-UH-301, a selective agonist of 5-HT(1A) receptor, had no modulatory effect on I(5-HT). These results suggest that in the membrane of TG neurons, the activation of 5-HT2 receptors can exert an enhancing effect on the function of coexistent 5-HT3 receptors while that of 5-HT(1A) receptors cannot.
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PMID:Potentiation of 5-HT3 receptor function by the activation of coexistent 5-HT2 receptors in trigeminal ganglion neurons of rats. 1552 17