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Query: UNIPROT:P46098 (5-HT3 receptor)
 2,290 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rats exposed to high pressure developed locomotor and motor activity (LMA) that correlated with an increase of DA release in both the nucleus accumbens and the caudate-putamen. We investigated the effects of the 5-HT3 receptor antagonist MDL 72222 on these pressure-induced neurochemical and behavioral disorders. MDL 72222 totally blocked the pressure-induced increase in accumbens DA release and the development of LMA, whereas it only reduced the increase in striatal DA release. This suggest that both LMA and the increase of DA release in the nucleus accumbens, but not in the caudate-putamen, could specifically result from a 5-HT3 receptor activation in rats exposed to high pressure.
Neurosci Lett 1995 Sep 01
PMID:Involvement of 5-HT3 receptor in the pressure-induced increase in striatal and accumbens dopamine release and the occurrence of behavioral disorders in free-moving rats. 854 56

1. In vivo microdialysis was used to study the effect of phenylbiguanide (PBG), a 5-hydroxytryptamine3 receptor agonist, on the extracellular output of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the corpus striatum. 2. PBG produced a dose-related (10-500 microM) increase in the release of dopamine (280-2000%). DOPAC and HVA output decreased with the perfusion of PBG. This decrease was similar with 50-500 microM PBG. 5-HIAA output was not affected by any PBG concentration used. 3. When nomifensine (5 microM) was included in the Ringer solution, the effect of PBG on the release of dopamine was ameliorated or inhibited. However, the effect of PBG (50-500 microM) on the extracellular output of DOPAC and HVA was similar in the absence and in the presence of nomifensine (5 microM). 4. Perfusion of MDL 72222, a 5-hydroxytryptamine3 receptor antagonist, at doses of 50 and 100 microM produced similar decreases (50% of controls) and increases (120% of controls) in the extracellular output of dopamine and DOPAC, respectively. HVA and 5-HIAA output levels were not affected by either concentration of MDL 72222. MDL 72222 (10 microM) produced a slight and transient increase in the release of dopamine and a decrease in the extracellular output of DOPAC. HVA and 5-HIAA extracellular output was not affected by MDL 72222 (10 microM) perfusion. 5. Co-perfusion of MDL 72222 (10 and 100 microM) or tetrodotoxin (1 microM) with PBG (50 microM) did not modify the effect produced by PBG (50 microM) alone on the release of dopamine. 6 These results suggest that the effect of PBG on the release of dopamine is mainly carrier-mediated.
Br J Pharmacol 1995 Sep
PMID:5-HT3 receptor agonist induced carrier-mediated release of dopamine in rat striatum in vivo. 856 17

In this study we have investigated the acute and chronic effects of cisplatin on whole cell currents in cultured dorsal root ganglion neurones. Consistent with effects on action potentials measured under current clamp, acute (5 min) application of cisplatin (5 microM) attenuated voltage-activated potassium, and mixed cation currents by approximately 50% in both cases. Chronic treatment (5-7 days) of cultured neurones with 5 microM cisplatin also resulted in greatly reduced voltage-activated potassium currents (by 50%) and calcium currents (by 60%) compared to events recorded from neurones not treated with cisplatin. In contrast, the amplitude of inward cation current activated by hyperpolarization was doubled by 5-12 days treatment with cisplatin. Studies on action potential after-depolarizations and calcium-activated chloride currents suggest that cisplatin disturbs calcium homeostatic mechanisms. These observations may account for anode break spike excitation and the low efficiency with which cells buffer intracellular calcium following cisplatin treatment. Dexamethasone has been found to enhance the anti-emetic effects of 5-HT3 receptor antagonists in patients treated with cisplatin. For this reason the actions of dexamethasone were studied in combination with cisplatin treatment. Although acute application of dexamethasone (1-10 microM) produced transient depolarizations and bursts of action potentials, after 5 minutes application it had no effect on membrane potential, input resistance, or the properties of action potentials evoked by depolarizing current commands.(ABSTRACT TRUNCATED AT 250 WORDS)
Naunyn Schmiedebergs Arch Pharmacol 1995 Sep
PMID:An electrophysiological investigation of the effects of cisplatin and the protective actions of dexamethasone on cultured dorsal root ganglion neurones from neonatal rats. 858 39

Most anticancer drugs are cytotoxic and produce various side-effects, among which nausea and vomiting are almost ubiquitous and usually extremely distressing to the patient. Cancer chemotherapy elicits two main phases of vomiting: an intense, acute phase of vomiting that occurs almost immediately following anti-cancer therapy and a milder, delayed phase of nausea and vomiting of longer duration. The mechanisms underlying the induction of nausea and vomiting after cancer chemotherapy are poorly understood but may be mediated by serotonin (5-hydroxytryptamine or 5-HT), particularly in the acute phase. Serotonin activates 5-HT3 receptors, which function as ligand-gated ion channels located either in the periphery and/or in the central nervous system to produce emesis, among other effects. The peripheral 5-HT3 receptors may be pharmacologically distinct from the central 5-HT3 receptors and may exhibit some association with GTP-binding proteins. In addition, different populations may exist as distinct subtypes of the same receptor. The 5-HT3 receptor antagonist ondansetron (GR 38032F) is effective in preventing the emesis induced by cytotoxic agents currently used in the treatment of many forms of cancer. Ondansetron has, comparatively, a much higher efficacy in the treatment of acute emesis following cancer chemotherapy than it does in the delayed phase, suggesting that the late phase of emesis may be mediated by other distinct mechanisms.
Biochem Pharmacol 1996 Sep 13
PMID:Role of 5-hydroxytryptamine3 (5-HT3) antagonists in the prevention of emesis caused by anticancer therapy. 876 66

The serotonin 5-HT3 receptor is unique among the seven serotonin receptor "families" that have been recognized so far. It functions not as a G-protein coupled but as a direct ion channel gated receptor. Because of the varied neural functions linked to this receptor, intensive research interest has developed in recent years about its basic and clinical pharmacology, which are summarized in this review. Some new agonists and many new antagonists have been developed. These agents have a useful role as selective pharmacologic research probes, and some of them can be used therapeutically as potent and selective anti-nausea and antiemetic drugs, particularly in patients undergoing cancer chemotherapy treatment or general anesthesia procedures. Potential applications of these agents include the treatment of some behavioral disorders in mental disease, drug addiction, and certain types of pain syndromes.
J Clin Pharmacol 1995 Sep
PMID:5-HT3 receptors: pharmacologic and therapeutic aspects. 878 44

Nausea and vomiting are the most frequently reported adverse effects of cancer chemotherapy and have a significant impact on patients' daily functioning, quality of life and compliance with chemotherapy. Summarized in this article are the recommendations for the optimal management of nausea and vomiting developed by a multidisciplinary group of health care professionals. Issues relating to chemotherapy-induced nausea and vomiting are discussed; general principles of treatment are reviewed; treatment algorithms based on emetogenicity and types of chemotherapy are presented; and the importance of issues including non-pharmacological approaches, patient education and pharmacoeconomic perspectives are considered. The goal of antiemetic therapy should be no episodes of vomiting or retching and minimal or no nausea. Data from clinical trials support the clear superiority of 5-HT3 receptor antagonists in a variety of clinical situations. Their cost must be considered not only as an isolated item from the institutional perspective, but also from the perspective of the impact of successful therapy on the patient.
Can J Oncol 1995 Sep
PMID:Guidelines for the optimal management of chemotherapy-induced nausea and vomiting: a consensus. 885 13

The R- and S-enantiomers of the 4,5,6,7-tetrahydro-1H-benzimidazole derivatives 3-8 were prepared by optical resolution. Each R-isomer, except for 3, was almost two orders of magnitude more potent than its S-isomer as a 5-hydroxytrptamine (5-HT3) receptor antagonist, as judged from they effect on the von Bezold-Jarisch reflex (B. J. reflex) in rats, the contraction of isolated guinea-pig colon and the receptor-binding affinity. The (--)-(R)-5-[(1-methyl-1H-indol-3-yl)carbonyl] derivative 6R.HCl (ramosetron = YM060) and (--)-(R)-5-[(1-indolinyl)carbonyl] derivative 4R.HCl (YM114 = KAE-393) given p.o. were hundreds of times more potent than 1 (ondansetron) and 2 (granisetron) in their inhibitory effects on cisplatin-induced emesis in ferrets and restraint stress-induced increases in fecal pellet output in rats. Three-dimensional molecular modeling studies suggested that the 'chiral selection' of the enantiomers might be influenced by the steric repulsion between the aromatic ring part and the conformationally restricted 4,5,6,7-tetrahydro-1H-benzimidazole ring in "equatorial-twist" conformation. In our pharmacophore model for the 5-HT3 receptor antagonist, a basic center exists at the left side of the aromatic-carbonyl plane when viewing from the aromatic part with the carbonyl oxygen atom upwards, whereas the "handedness" is ambiguous in the previously proposed model.
Chem Pharm Bull (Tokyo) 1996 Sep
PMID:Novel 5-hydroxytryptamine (5-HT3) receptor antagonists. III. Pharmacological evaluations and molecular modeling studies of optically active 4,5,6,7-tetrahydro-1H-benzimidazole derivatives. 885 65

In physicochemical and pharmacokinetic evaluations of (--)-(R)-5-[(1-methyl-1H-indol-3-yl)carbonyl] -4,5,6,7-tetrahydro-1H-benzimidazole hydrochloride 1 (YM060: ramosetron), which is a highly potent 5-hydroxytryptamine(-HT3) receptor antagonist, 4-hydroxy-6-[(1-methyl-1H-indol-3-yl) carbonyl]4,5,6,7-tetrahydro-1H-benzimidazole 2 was identified as a degradation product and metabolite of 1. The (--)-(4R,6S)-isomer 2 was synthesized from the diketone derivative 3, via the stereoselective reduction of 3 followed by the stereocontrolled epimerization of the (--)-(4S,6S)-isomer 10, the epimer of 2. The stereochemistry of 2 and 10 was determined by NMR and HPLC studies. Compounds 2 and 10 were found to be potent 5-HT3 receptor antagonists, like 1. Among the other oxidation products, the diketone derivatives 3 and 7 and the dihydroxylated derivative 4 retained antagonistic activity similar to that of ondansetron. This is of interest, because they do not possess the amine group which is known to be necessary for high affinity to the 5-HT3 receptor.
Chem Pharm Bull (Tokyo) 1996 Sep
PMID:Novel 5-hydroxytryptamine (5-HT3) receptor antagonists. IV. Synthesis and pharmacological evaluation of the oxidation products of (-)-(R)-5-[(1-methyl-1H-indol-3-yl)carbonyl] -4,5,6,7-tetrahydro-1H-benzimidazole hydrochloride (YM060: ramosetron). 885 66

Three 5-HT3 receptor antagonists, MDL 72222, tropisetron, and ondansetron were studied for their ability to modify the conditioned place preference (CPP) induced by 10 mg/kg IP cocaine in rats. MDL 72222 (0.03-3 mg/kg SC) and tropisetron (0.01-0.1 mg/kg SC) administered, respectively, 30 min and 1 h before each conditioning session, did not affect the acquisition of cocaine CPP. Ondansetron (0.01-0.1 mg/kg SC) administered 30 min before each conditioning session or just before testing likewise had no effect. At 0.1 mg/kg SC ondansetron did not modify the increase of extracellular dopamine caused by 10 mg/kg cocaine in the nucleus accumbens. The results suggest that 5-HT3 receptor antagonists have no effect on the rewarding properties of cocaine or on the behaviour elicited by the stimuli previously associated with the drug's action.
Pharmacol Biochem Behav 1996 Sep
PMID:5-HT3 receptor antagonists do not modify cocaine place conditioning or the rise in extracellular dopamine in the nucleus accumbens of rats. 887 35

The aim of the work was to evaluate the impact of cyclophosphamide and ondansetron on serotonin metabolism measured by urinary 5-hydroxyindoleacetic acid (5-HIAA) excretion. The pattern of urinary 5-HIAA excretion was analysed within 24 h following cyclophosphamide, epirubicin and 5-fluorouracil (FEC) chemotherapy (n = 14), ondansetron as single agent (n = 31), and in a control group (n = 62). 5-HIAA was measured by a fluorescence/polarisation immunoassay. Both FEC and ondansetron alone induced a significantly higher 5-HIAA increase following the first 12 h after drug administration when compared to the control group. The comparison of quantitative variables of 5-HIAA excretion between FEC and ondansetron failed to reveal any statistical differences. Cyclophosphamide-based chemotherapy is associated with only minor increases of 5-HIAA excretion. Analysis of 5-HIAA excretion does not help in the description of the pathophysiology of cyclophosphamide-induced emesis. In contrast to experimental data, serotonin 3 receptor antagonism with ondansetron induces an increase of 5-HIAA excretion in humans.
Support Care Cancer 1996 Sep
PMID:5-Hydroxyindoleacetic acid excretion following combination chemotherapy with cyclophosphamide, epirubicin and 5-fluorouracil plus ondansetron compared to ondansetron alone. 888 33


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