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

The emetic profile of action of cisplatin 5 and 10 mg/kg i.p. was investigated in the ferret over a 72 and 24 hr period respectively. The 5-HT3 receptor antagonists ondansetron and alosetron markedly antagonized or abolished the emesis during the "acute phase" and, whilst antagonizing the emesis during the delayed phase, also revealed a 5-HT3 receptor antagonist resistant component. These cisplatin paradigms may provide models relevant to the study of acute and delayed emesis induced by cisplatin in man.
Neuropharmacology 1994 Dec
PMID:Effects of 5-HT3 receptor antagonists on models of acute and delayed emesis induced by cisplatin in the ferret. 776 Sep 83

We have used single-cell imaging of fura-2-loaded cells to examine the Ca2+ signals evoked by activation of 5-hydroxytryptamine type 3 (5-HT3) receptors in undifferentiated N1E-115 neuroblastoma cells and in human embryonic kidney (HEK) 293 cells transfected with either of the two cloned 5-HT3 receptor subunits. The selective 5-HT3 receptor agonist 1-(m-chlorophenyl)-biguanide (mCPBG) caused a concentration-dependent increase in the cytoplasmic Ca2+ concentration ([Ca2+]i) in N1E-115 cells and in HEK 293 cells transfected with either the 5-HT3 A subunit or the 5-HT3 As subunit. In each case, the [Ca2+]i rise was steeply dependent on the mCPBG concentration (nH = 2-4) and abolished by removal of extracellular Ca2+ or addition of ondansetron. Pretreatment of N1E-115 cells with thapsigargin, caffeine, and ryanodine to deplete intracellular Ca2+ stores had no effect on the mCPBG-evoked Ca2+ signals, indicating that they result entirely from stimulated Ca2+ entry. The steep concentration-effect curves therefore are not a consequence of amplification of Ca2+ influx by Ca(2+)-induced Ca2+ release from intracellular stores and probably reflect cooperative activation of 5-HT3 receptors by mCPBG. Depolarization of transfected HEK 293 cells with medium containing increased K+ concentrations invariably failed to evoke an increase in [Ca2+]i, confirming the absence of voltage-gated Ca2+ channels and indicating that the mCPBG-evoked rise in [Ca2+]i results from Ca2+ permeation of 5-HT3 receptors. However, in N1E-115 cells and transfected HEK 293 cells, both extracellular Na+ and K+ substantially inhibited the Ca2+ influx evoked by activation of 5-HT3 receptors, possibly by inhibition of agonist binding or by competition with Ca2+ for permeation of the channel. We conclude that 5-HT3 receptors are Ca2+ permeant, that the Ca2+ influx is sufficient to generate a significant rise in [Ca2+]i, and that, because the A and As subunits behave similarly, conflicting electrophysiological analyses of Ca2+ currents cannot be explained by differences between these two subunits.
Mol Pharmacol 1994 Dec
PMID:Ca2+ permeability of cloned and native 5-hydroxytryptamine type 3 receptors. 780 32

1. A study was made of the effects of 5-hydroxytryptamine (5-HT) on pressor response induced in vivo by electrical stimulation of the sympathetic outflow from the spinal cord of pithed rats. All animals had been pretreated with atropine. Intravenous infusion of 5-hydroxytryptamine at doses of 10 and 20 micrograms kg-1 min-1 reduced the pressor effects obtained by electrical stimulation at intervals of 10 min over the 1 h of infusion. 2. This inhibitory action of 5-HT was depressed by cyproheptadine and methiothepin but was not modified by ketanserin or MDL-72222. By contrast, the inhibitory action of 5-HT was lost in pithed rats that had been pretreated with exogenous noradrenaline. 3. The 5-HT1 receptor agonist 5-carboxamidotryptamine (5-CT) caused an inhibition of the pressor response, whereas the 5-HT3 receptor agonist, 1-phenylbiguanide, produced a variable but significant increase in the pressor response. The 5-HT2 receptor agonist, m-CPP, did not modify the pressor sympathetic response. 4. Our results suggest that 5-hydroxytryptamine interferes with sympathetic neurotransmission by inhibiting pressor effects as a result of stimulation of the complete sympathetic outflow, and that this inhibition is mainly through a presynaptic 5-HT1 mechanism.
Br J Pharmacol 1994 Dec
PMID:Inhibitory 5-hydroxytryptamine receptors involved in pressor effects obtained by stimulation of sympathetic outflow from spinal cord in pithed rats. 788 92

The emetic effects of five anticancer drugs, cyclophosphamide, nitrogen mustard-N-oxide, actinomycin D, 5-fluorouracil and L-asparaginase, and the effects of bilateral abdominal vagotomy and bilateral greater splanchnic nerve section or a 5-HT3 receptor antagonist on the emesis induced by these drugs were investigated in dogs. Cyclophosphamide (20 mg/kg, i.v.), nitrogen mustard-N-oxide (5 mg/kg, i.v.) and actinomycin D (50 micrograms/kg, i.v.) caused vomiting in dogs with a long latency period. 5-Fluorouracil (5 mg/kg, i.v.) and L-asparaginase (2000 K.U./kg, i.v.) failed to induce vomiting. Bilateral abdominal vagotomy and bilateral greater splanchnic nerve section completely inhibited the vomiting induced by the former three anticancer drugs. Furthermore, the vomiting was inhibited completely by intravenous administration of ICS205930 (2 x 0.1 mg/kg), a 5-HT3 receptor antagonist. These results suggest that activation of visceral afferents through 5-HT3 receptors mediates the vomiting induced by cyclophosphamide, nitrogen mustard-N-oxide and actinomycin D.
Eur J Pharmacol 1993 Dec 07
PMID:Emetic effects of anticancer drugs and involvement of visceral afferent fibers and 5-HT3 receptors in dogs. 811 85

YM114 (KAE-393), (R)-5-[(2,3-dihydro-1-indolyl)carbonyl]-4,5,6,7- tetrahydro-1H-benzimidazole hydrochloride, is a derivative of YM060, a potent 5-HT3 receptor antagonist. We investigated the effects of YM114 on 5-HT3 receptors, both in vitro and in vivo, and on bowel dysfunction induced by restraint stress, 5-HT and thyrotropin-releasing hormone (TRH), and compared them with the effect of trimebutine. YM114 dose dependently inhibited the reduction in heart rate induced by 5-HT (30 micrograms/kg i.v.) in rats (ED50 = 0.31 micrograms/kg i.v.), and the potency of YM114 was almost the same as that of the racemate. The S-form of YM114 also inhibited 5-HT-induced bradycardia, but 1350 times less potent than the R-form. YM114 and its S-form inhibited [3H]GR65630 binding to N1E-115 cell membranes in a concentration-dependent manner with Ki values of 0.341 and 616 nM, respectively, showing the isomeric activity ratio (R-/S-form) of YM114 to be much greater (1800). YM114 antagonized 5-HT-induced depolarization of the nodose ganglion (EC50 = 1.39 nM). Trimebutine (1 mg/kg i.v.) failed to inhibit 5-HT-induced bradycardia, implying that it does not possess 5-HT3 receptor antagonistic activity. YM114 significantly and dose dependently prevented restraint stress-, 5-HT- and TRH-induced increases in fecal pellet output, and restraint stress- and 5-HT-induced diarrhea in rats and mice (ED50 = 6.9, 72.5, 154.6, 9.7 and 52.4 micrograms/kg p.o., respectively). Trimebutine significantly prevented stress- and 5-HT-induced diarrhea (ED50 = 29.4 and 87.3 mg/kg p.o., respectively), but only partially affected stress-, 5-HT- and TRH-induced increases in fecal pellet output. Thus, YM114 is a potent and stereoselective 5-HT3 receptor antagonist with much greater protective effects against stress-induced defecation than trimebutine.
Eur J Pharmacol 1993 Dec 07
PMID:Comparison of the effects of trimebutine and YM114 (KAE-393), a novel 5-HT3 receptor antagonist, on stress-induced defecation. 811 88

The management of chemotherapy-induced nausea and emesis presents a major problem in children with cancer. The anti-emetic properties of the 5-HT3 receptor antagonist ondansetron are well documented in adults receiving cytotoxic chemotherapy. Experience in the treatment of children is still limited. Here we present a review of the literature on the anti-emetic treatment with ondansetron in children. Moreover, we provide recommendations on the use of ondansetron during anti-neoplastic chemotherapy and radiotherapy in pediatric oncology.
Anticancer Drugs 1993 Dec
PMID:Ondansetron in the control of chemotherapy-induced and radiotherapy-induced emesis in children with malignancies. 813 11

One-hundred and forty-five chemotherapy patients receiving cisplatin- and non-cisplatin-containing regimens participated in an open evaluation of ondansetron, a 5-HT3 receptor antagonist, in the prophylaxis of acute and delayed nausea and vomiting. The study had two groups of patients, one receiving cisplatin-containing regimens (Group A) and the other, non-cisplatin-containing regimens (Group B). There were 51 patients recruited to Group A. Ondansetron was given to these patients at a dose of 8 mg intravenously 15 min before chemotherapy, followed by an intravenous infusion for 24 h (1 mg/h), or 8 mg intravenously 4 and 8 h after the start of cisplatin, followed by 8 mg orally three times/day for 5 days. Ninety-four patients were recruited to Group B: these patients received ondansetron at a dose of 8 mg intravenously immediately before chemotherapy or 8 mg orally 1-2 h prior to it, and 8 mg orally three times/day for 3-5 days. For acute emesis (first 24 h), complete control was achieved in 79.5% of Group A patients and in 78.1% of Group B. For delayed emesis (days 2-5), 79.7% of Group A patients and 84.6% of Group B were completely protected during the entire study period. Nausea was also well controlled with ondansetron; 83.2% (Group A) and 86.5% (Group B) reported only mild nausea or no nausea at all. Ondansetron was effective in the control of both cisplatin- and non-cisplatin-induced emesis and well tolerated without any serious drug-related adverse events.
Anticancer Drugs 1993 Dec
PMID:Ondansetron in the treatment of nausea and vomiting induced by chemotherapy. Portuguese Ondansetron Study Group. 813 12

The budgetary implications of using 5-HT3 receptor antagonists in the management of patients with chemotherapy-induced emesis is discussed. It was shown that treatment with 5-HT3 receptor antagonists in the acute phase of emesis resulted in relatively little additional cost when introduced into a normal management pattern of emesis control, and therefore seems justifiable. However, in delayed emesis there is a much more substantial budgetary impact with no proven clinical benefit, and therefore treatment does not appear to be appropriate in this situation.
Anticancer Drugs 1993 Dec
PMID:Modeling budgetary impact for decision makers. 813 15

Budgetary restraints have been used to limit the freedom of medical prescription. This paper proposes a simple approach to the evaluation of costs and benefits. First the efficacy of a new approach is defined and compared with the best care with existing means. The incremental gain is then compared with the true cost of both procedures. The innovation should be adopted only where the gain is high and the cost low (or at least only minimally increased). In cases of debatable gain and costs, detailed cost-benefit analysis and quality of life studies are needed. We conclude that at present, 5-HT3 receptor antagonists should only be used to control the acute phase of emesis.
Anticancer Drugs 1993 Dec
PMID:A framework for assessing therapeutic innovation. 813 16

This paper reviews recent anti-emetic developments, with particular reference to the 5-HT3 receptor antagonists. These drugs are at least as effective as conventional regimens for controlling acute nausea and vomiting in patients receiving highly or moderately emetogenic chemotherapy and abdominal radiotherapy. They have less side effects than do alternative drugs. Improved control of acute nausea and vomiting by 5-HT3 receptor antagonists seems to reduce anticipatory symptoms in subsequent cycles. Dexamethasone enhances activity of 5-HT3 receptor antagonists in highly emetogenic chemotherapy. Improved control of acute nausea and vomiting by 5-HT3 receptor antagonists may remove one obstacle to offering palliative chemotherapy.
Anticancer Drugs 1993 Dec
PMID:Assessing the benefits of anti-emetic innovation. 813 17


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