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)

There is interest in the development of antiemetics other than dopamine receptor antagonists for the treatment of postoperative nausea and vomiting. A ferret model of morphine-induced emesis may have wider application in evaluating newer agents than the apomorphine dog model. This study describes the conditions for morphine-induced emesis in ferrets and evaluates five antiemetics that are prototypical of three different mechanisms. The average numbers of vomiting and retching episodes induced by morphine (0.1-2.5 mg/kg s.c.) were distributed as a bell-shaped curve. Maximum number of vomits occurred at 0.3 mg/kg (11.8 +/- 2.1 vomits; 45 +/- 12.5 retches). Antiemetics or vehicle were given i.v. 5 min prior to morphine while each ferret was maintained under isoflurane-O2 anesthesia. Ondansetron, a 5-HT3 receptor antagonist, reduced vomiting episodes by 47% and 70% (3 and 10 mg/kg). Granisetron, a 5-HT3 receptor antagonist was inactive at doses of 0.1, 1.0, 3.0 and 10 mg/kg. Metoclopramide reduced vomiting episodes by 48% and 82% (3 and 10 mg/kg). Droperidol reduced vomiting episodes by 84% at 3 mg/kg. Naloxone reduced vomiting episodes by 91% and 43% at doses of 0.1 and 1.0 mg/kg. In most cases, prolonged latency times to the first episodes accompanied the reduction in total numbers of episodes. The significant reduction of morphine-induced emesis in the ferret by ondansetron, metoclopramide and droperidol is consistent with the reduction of postoperative emesis in man by these compounds when morphine was a component of the anesthetic regimen. These results suggested that the morphine ferret model may be useful for evaluating compounds having the potential for preventing and treating postoperative vomiting.
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PMID:The effects of different antiemetic agents on morphine-induced emesis in ferrets. 822 24

In this randomized, double-blind, parallel group, placebo-controlled, dose-ranging study, we have compared three doses (0.1 mg, 1.0 mg and 3.0 mg) of the 5-HT3 receptor antagonist, granisetron (Kytril), as prophylactic therapy for the prevention of postoperative nausea and vomiting. The aims were to determine the optimal dose of granisetron and to evaluate its safety profile. We studied 527 adult patients, undergoing elective open abdominal surgery or vaginal hysterectomy during general anaesthesia. Antiemetic prophylaxis with a single dose of granisetron 1.0 mg or 3.0 mg resulted in a significant reduction (P < 0.001 compared with placebo) in the numbers of patients experiencing postoperative vomiting, or nausea, or who achieved total control during the postoperative periods 0-6 h and 0-24 h. The two higher doses of granisetron (1.0 mg and 3.0 mg) provided effective prophylaxis against vomiting, with 78% and 77% of patients, respectively, being free from vomiting in the first 6 h after surgery, and 63% and 62% in the first 24 h. This compares with 50% and 34% at 0-6 h and 0-24 h, respectively, in the placebo group. Granisetron was well tolerated and the optimum dose was 1.0 mg.
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PMID:Single-dose i.v. granisetron in the prevention of postoperative nausea and vomiting. 865 23

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.
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PMID:5-HT3 receptors: pharmacologic and therapeutic aspects. 878 44

The antiemetic activity of droperidol is attributed to antagonizing the dopaminergic neurons of the chemoreceptor trigger zone. Ondansetron is a serotonin (5HT) receptor antagonist at both peripheral and central 5-HT3 receptor sites with no known action on dopamine-mediated activity. We hypothesized that the combination of these two antiemetics would be more effective than droperidol alone. Women with ASA classified physical status I or II, scheduled for laparoscopic tubal banding, participated in a randomized double-blind clinical trial using a standardized anesthesia regimen. Within 15 min after induction of anesthesia, Group 1 (n = 60) received IV droperidol 1.25 mg and ondansetron 4 mg and Group 2 (n = 60) received IV droperidol 1.25 mg and saline. Before surgery and during recovery at 1, 2, and 24 h, emetic episodes, nausea, pain, drowsiness, medications taken, and adverse events were recorded. The complete response (no emesis, no rescue) for Group 1 was 55 of 60 (91.6%) versus 47 of 60 (78.3%) in Group 2 (P = 0.04). No patient needed rescue antiemetic medication in Group 1, whereas 5 of 60 (8.3%) patients were rescued in Group 2 (P = 0.03). There were seven emetic episodes in five patients in Group 1 and 30 emetic episodes in 12 patients in Group 2 over the 24-h study period (P = 0.03). The time to the first emetic episode was more than twice as long for Group 1 than Group 2 (P = 0.03) and total nausea scores were lower in Group 1 than Group 2 (P = 0.01). The droperidol/ondansetron combination was significantly superior to droperidol in complete response, time to and number of emetic episodes, and the incidence and severity of nausea in women having tubal banding.
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PMID:Droperidol/ondansetron combination controls nausea and vomiting after tubal banding. 917 30

Efficiency of ondansetron, a selective 5-HT3 receptor antagonist, in prevention of postoperative nausea and vomiting in 40 ASA I-II patients who will undergo emergency intraabdominal operations is studied in a randomized double-blind and placebo controlled study. Patients of no premedication are administered 4 mg i.v. ondansetron or placebo (saline) before induction. Thiopental (4 mg/kg) was used for induction, succinylcholine (2 mg/kg) for muscular relaxation, and 50% nitrous oxide in oxygen and isoflurance (0.8-1.5%) for the maintenance of anesthesia, and fentanyl and norcuron were administered when necessary. Vital signs were closely monitored and recorded during anesthesia and early postoperative period. Study is carried out during postoperative 0-1 h, 1-2 h and 2-24 h periods. Nausea scores and emesis were recorded during 0-1 and 1-2 h periods. Ondansetron was found significantly more effective than placebo (p < 0.05 and p < 0.05). Although is was effective during 2-24 h period, the difference was not statistically significant (p > 0.05). No significant difference was observed between the groups in terms of vital findings, laboratory findings and side effects (p > 0.05). Therefore it is concluded that administration of prophylactic i.v. ondansetron to patients undergoing emergency intraabdominal operations is effective in prevention of nausea and vomiting without any significant side effects.
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PMID:Prophylactic administration of ondansetron in emergency intraabdominal operations. 899 79

The use of ondansetron, a selective serotonin 5-HT3 receptor antagonist, is well established in patients with nausea and vomiting associated with cancer chemotherapy, radiotherapy or anaesthesia and surgery. The wide distribution of 5-HT3 receptors in the body and the role of these receptors in disease have provided the rationale for investigation of ondansetron in novel applications. Preliminary data have shown ondansetron to have clinical benefit in patients with nausea and vomiting associated with drug overdosage or poisoning, anti-infective or antidepressant therapies, uraemia or neurological trauma, and in patients with pruritus. Patients with gastrointestinal motility disorders (e.g. carcinoid syndrome, irritable bowel syndrome, diarrhoea associated with cryptosporidiosis or diabetes, and chronic refractory diarrhoea) have also shown some improvement when treated with ondansetron, as have patients with certain pain or CNS-related disorders [e.g. alcohol (ethanol) dependence, opiate withdrawal, vertigo, cerebellar tremor and Parkinson's disease treatment-related psychosis]. In contrast to conventional antiemetics, ondansetron is generally well tolerated with a lower incidence of sedation and only isolated case reports of extrapyramidal reactions. Furthermore, unlike dopamine receptor-blocking neuroleptics, ondansetron does not appear to worsen the symptoms of Parkinson's disease. Thus, in addition to its established indications, preliminary results suggest that ondansetron may be beneficial in a number of novel applications. This drug may represent a treatment alternative in patients with refractory disease, or an effective treatment of conditions for which current therapies are either poorly tolerated or not available. Further investigation of ondansetron in a range of potential new applications appears to be warranted.
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PMID:Ondansetron. A review of its pharmacology and preliminary clinical findings in novel applications. 911 22

The ability of 2,2,2-trichloroethanol (TCE) and related alcohols to modify the 5-hydroxytryptamine3 (5-HT3) receptor-mediated depolarisation of the rat isolated cervical vagus nerve were investigated by extracellular electrophysiological recording using the 'grease gap' technique. TCE at millimolar concentrations increased the magnitude of the 5-HT3 receptor-mediated depolarisations of the rat vagus nerve by a number of agonists (5-HT, phenylbiguanide (PBG), quipazine). Concentration response curves generated for the 5-HT3 receptor agonists. 5-HT and PBG, in the absence and presence of TCE (5 mM) indicated that the potentiation in agonist-induced depolarisation was due to an increase in both agonist potency and apparent efficacy. Following apparent complete 5-HT3 receptor desensitisation (induced by either 5-HT or PBG; 100 microM for 90 min), application of TCE (5 mM) in the continued presence of either agonist induced a depolarisation of the vagus nerve. In addition to TCE, a number of related alcohols (tribromoethanol, isopentanol and 5-chloropentanol but not ethanol) at millimolar concentrations also potentiated depolarisation of the vagus nerve induced by 5-HT. Combined application of both TCE (0.1-20 mM) and isopentanol (20 mM) indicated that the potentiation of the 5-HT3 receptor-mediated depolarisation by these alcohols was not additive. The present studies indicate that the 5-HT3 receptor expressed on the cervical vagus nerve is susceptible to allosteric modulation by a number of alcohols including the anaesthetic agent TCE. Such an interaction may have relevance to the nausea and vomiting experienced by some patients following recovery from general anaesthesia.
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PMID:5-hydroxytryptamine3 (5-HT3) receptor-mediated depolarisation of the rat isolated vagus nerve: modulation by trichloroethanol and related alcohols. 972 27

1. General anesthetics have been shown to inhibit synaptic transmission in multiple areas of the central and peripheral nervous systems. 2. The mechanism of inhibition is not well understood. 3. It has become clear that general anesthetics modulate the function of members of the ligand gated ion channel superfamily, including receptors for GABA(A), glycine (Harrison et al., Mol. Pharmacol. 44(3), 1993, 628-632) and 5HT3 (Zhou and Lovinger, J. Pharmacol. Exp. Therap. 278(2), 1996, 732-740). 4. Studies of the activity of general anesthetics on recombinant neuronal nicotinic acetylcholine receptors have added this receptor family to those potently inhibited by general anesthetics (Flood et al., Anesthesiology 86(4), 1997, 859-865; Violet et al., Anesthesiology 86(4), 1997, 866-874). 5. Studies of neuronal nicotinic receptors in native neurons suggest that the inhibition of these receptors by general anesthetics at low clinical concentrations may be biologically significant (Nicoll, Science 199(4327), 1978, 451-452). 6. Recent work on neuronal nicotinic acetylcholine receptors in the central nervous system suggests that their primary role may be to modulate synaptic transmission (Role and Berg, Neuron 16(6), 1996, 1077-1085). 7. Thus, inhibition of nicotinic modulation in the central nervous system may result in inhibition of synaptic transmission and some of the behavioral consequences of general anesthesia.
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PMID:Neuronal nicotinic acetylcholine receptor modulation by general anesthetics. 1004 35

Minimally invasive therapy aims to minimize the trauma of any interventional process but still achieve a satisfactory therapeutic result. The development of "critical pathways," rapid mobilization and early feeding have contributed towards the goal of shorter hospital stay. This concept has been extended to include laparoscopic cholecystectomy and hernia repair. Reports have been published confirming the safety of same day discharge for the majority of patients. However, we would caution against overenthusiastic ambulatory laparoscopic cholecystectomy on the rational but unproven assumption that early discharge will lead to occasional delays in diagnosis and management of postoperative complications. Intraoperative complications of laparoscopic surgery are mostly due to traumatic injuries sustained during blind trocar insertion and physiologic changes associated with patient positioning and pneumoperitoneum creation. General anesthesia and controlled ventilation comprise the accepted anesthetic technique to reduce the increase in PaCO2. Investigators have recently documented the cardiorespiratory compromise associated with upper abdominal laparoscopic surgery, and particular emphasis is placed on careful perioperative monitoring of ASA III-IV patients during insufflation. Setting limits on the inflationary pressure is advised in these patients. Anesthesiologists must maintain a high index of suspicion for complications such as gas embolism, extraperitoneal insufflation and surgical emphysema, pneumothorax and pneumomediastinum. Postoperative nausea and vomiting are among the most common and distressing symptoms after laparoscopic surgery. A highly potent and selective 5-HT3 receptor antagonist, ondansetron, has proven to be an effective oral and IV prophylaxis against postoperative emesis in preliminary studies. Opioids remain an important component of the anesthesia technique, although the introduction of newer potent NSAIDs may diminish their use. A preoperative multimodal analgesic regimen involving skin infiltration with local anesthesia. NSAIDs to attenuate peripheral pain and opioids for central pain may reduce postoperative discomfort and expedite patient recovery/discharge. There is no conclusive evidence to demonstrate clinically significant effects of nitrous oxide on surgical conditions during laparoscopic cholecystectomy or on the incidence of postoperative emesis. Laparoscopic cholecystectomy has proven to be a major advance in the treatment of patients with symptomatic gallbladder disease.
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PMID:Anesthetic implications of laparoscopic surgery. 1060 86

A complex sensitivity of afferent nerves in the mesentery of the rat jejunum to systemic administration of histamine has recently been demonstrated. In the present study, we aimed to characterize subpopulations of mesenteric afferents that mediate this afferent nerve response. Multiunit afferent discharge was recorded from mesenteric nerves supplying the proximal jejunum in anesthetized rats. The majority of mesenteric bundles (84%) exhibited biphasic responses to histamine (8 micromol/kg), and these bundles also responded to 2-methyl-5-HT (2m5HT). In contrast, monophasic responses lacked a short-latency component, and these bundles failed to respond to 2m5HT. Single-unit analysis revealed a population of afferents that possessed cosensitivity for 2m5HT and histamine. This population of afferents was absent in chronically vagotomized animals, whereas mucosal anesthesia with luminal lidocaine reversibly converted the biphasic profile to a monophasic one. Ondansetron (500 microg/kg) blocked the response to 2m5HT with no effect on the profile of the histamine response, whereas pyrilamine (5 mg/kg) blocked the histamine response without affecting the response to 2m5HT. We conclude that histamine-sensitive afferents exist in the rat proximal jejunum that also respond to 5-HT via the 5-HT3 receptor. These fibers appear to be vagal afferents originating in the intestinal mucosa and may be involved in the organization of mast cell-mediated responses.
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PMID:Cosensitivity of vagal mucosal afferents to histamine and 5-HT in the rat jejunum. 1218 Nov 74


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