Functional nausea and vomiting is a broad term used to be described a subset of individuals who have chronic nausea and vomiting without apparent cause, despite extensive evaluation. According to the Rome III criteria, functional nausea and vomiting can be subdivided into three separate entities: chronic idiopathic nausea, functional vomiting and cyclic vomiting syndrome. Although no specific test can diagnose these diseases, the diagnostic approach requires excellent history taking combined with judicious diagnostic testing to exclude some organic cause of chronic nausea and vomiting. These conditions are probably not psychogenic in origin. Treatment remains empirical for all patients with functional nausea and vomiting. Reassurance and supportive physician-patient relationship, along with use of low-dose tricyclic antidepressants, can be beneficial in caring for patients with chronic idiopathic nausea and functional vomiting. The cornerstones of management for patients with cyclic vomiting syndrome are identifying and avoidance of triggering factors, treatment with prophylactic antimigraine agents, 5-HT3 antagonists, benzodiazepines and 5-HT1 agonists (sumatriptan), with supportive therapy.
Antidepressive Agents, Tricyclic ; Benzodiazepines ; Diagnostic Tests, Routine ; Humans ; Nausea ; Rome ; Serotonin 5-HT1 Receptor Agonists ; Serotonin 5-HT3 Receptor Antagonists ; Vomiting

Migrating motor complex (MMC) is well characterized by the appearance of gastrointestinal contractions in the interdigestive state. This review article discussed the mechanism of gastrointestinal MMC. Luminal administration of 5-hydroxytryptamine (5-HT) initiates duodenal phase II followed by gastrointestinal phase III with a concomitant increase of plasma motilin release in conscious dogs. Duodenal 5-HT concentration is increased during gastric phase II and phase III. Intravenous infusion of motilin increases luminal 5-HT content and induces gastrointestinal phase III. 5-HT4 antagonists significantly inhibits both of gastric and intestinal phase III, while 5-HT3 antagonists inhibited only gastric phase III. These suggest that gastrointestinal MMC cycle is mediated via the interaction between motilin and 5-HT by the positive feedback mechanism. Gastric MMC is regulated via vagus, 5-HT3/4 receptors and motilin, while intestinal MMC is regulated via intrinsic primary afferent neurons and 5-HT4 receptors. Stress is highly associated with the pathogenesis of functional dyspepsia. Acoustic stress attenuates gastric phase III without affecting intestinal phase III in conscious dogs, via reduced vagal activity and increased sympathetic activity. It has been shown that subset of functional dyspepsia patients show reduced vagal activity and impaired gastric phase III. The physiological importance of gastric MMC is a mechanical and chemical cleansing of the empty stomach in preparation for the next meal. The impaired gastric MMC may aggravate dyspeptic symptoms following a food ingestion. Thus, maintaining gastric MMC in the interdigestive state is an important factor to prevent the postprandial dyspeptic symptoms.
Acoustics ; Animals ; Autonomic Pathways ; Contracts ; Dogs ; Dyspepsia ; Eating ; Enterochromaffin Cells ; Humans ; Infusions, Intravenous ; Meals ; Motilin ; Myoelectric Complex, Migrating ; Neurons, Afferent ; Phenobarbital ; Plasma ; Receptors, Serotonin, 5-HT4 ; Serotonin ; Serotonin 5-HT3 Receptor Antagonists ; Serotonin 5-HT4 Receptor Antagonists ; Stomach

PURPOSE: The purpose of this study is to investigate in vitro the effects of serotonin on the rat detrusor. In particular, this study examines what drugs inhibit the serotonin-induced detrusor contractions. MATERIALS AND METHODS: Isometric tension changes of isolated rat bladder muscle strips were recorded in an organ bath using a force transducer. Acute effects of serotonin (0.0001-0.01mM) were assessed on resting tension. Electrical field stimulation (EFS), bethanechol (0.0001-0.01mM), ATP (1-3mM) or KCl(63.5-254mM)-induced contractions using application in organ bath were compared with serotonin-induced contractions. In order to examine the action mechanism of serotonin-induced stimulation, EFS, bethanechol, ATP or KCl-induced contraction under serotonin (0.001mM) was assessed and serotonin (0.001 to 0.1mM) was cumulatively added to the organ bath following pre-incubation with propranolol, ketanserine, tropisetron, propiverine, sodium nitroprusside or doxazocin. RESULTS: There are two phases to the serotonin-induced responsean initial transient contraction and a prolonged tonic phase. Serotonin produced a reversible and dose-dependent contraction of the detrusor strips. Responses to bethanechol significantly increased with a concentration of 0.001mM serotonin (p<0.05). There was no effect on the responses to ATP, KCl, or EFS under 0.001mM serotonin. The 5-HT2 receptor is mainly responsible for serotonin-induced contractions of the detrusor (p<0.05), while the 5-HT1 receptor is partially responsible. Doxazocin and propiverine each significantly suppressed the responses to serotonin, while sodium nitroprusside and tropisetron each had no effect (p<0.05). CONCLUSIONS: Because the 5-HT2 antagonist blocked the effect of serotonin-induced bladder contractions and the stimulation of the adrenoreceptors, the 5-HT2 antagonist seems to improve lower urinary tract symptoms.
Adenosine Triphosphate ; Animals ; Baths ; Bethanechol ; Ketanserin ; Lower Urinary Tract Symptoms ; Nitroprusside ; Propranolol ; Rats ; Receptors, Serotonin, 5-HT1 ; Serotonin ; Serotonin 5-HT2 Receptor Antagonists ; Transducers ; Urinary Bladder ; Urinary Bladder, Overactive*

Irritable bowel syndrome is a group of symptoms that includes abdominal pain and changes in the form and frequency of stool. Since its symptoms are usually long-lasting, the disease significantly degrades quality of life. Several pharmacological therapies have been suggested according to the type of symptoms (e.g., abdominal pain, constipation, or diarrhea). In order to control abdominal pain, smooth muscle antispasmodics, antidepressants including tricyclic antidepressants and selective serotonin reuptake inhibitors, or 5-HT3 antagonists can be used. To improve constipation, dietary fiber or laxatives, 5-HT4 agonists, and chloride channel activators are available. Opioid agonists, mixed opioid agonists/antagonists such as eluxadoline, and bile salt sequestrants can be considered for diarrhea. In addition, probiotics and non-absorbable oral antibiotics can be used for the normalization of the gut microbiome and the treatment of small intestinal bacterial overgrowth, respectively. It is necessary to understand the characteristics of each drug and their combinations, because any single regimen cannot improve all symptoms in patients with irritable bowel syndrome. In this review, the mechanisms of action, efficacy, and adverse events associated with drugs used for irritable bowel syndrome are summarized.
Abdominal Pain ; Anti-Bacterial Agents ; Antidepressive Agents ; Antidepressive Agents, Tricyclic ; Bile ; Chloride Channel Agonists ; Constipation ; Diarrhea ; Dietary Fiber ; Drug Therapy* ; Gastrointestinal Microbiome ; Humans ; Irritable Bowel Syndrome* ; Laxatives ; Muscle, Smooth ; Parasympatholytics ; Probiotics ; Quality of Life ; Serotonin 5-HT3 Receptor Antagonists ; Serotonin 5-HT4 Receptor Agonists ; Serotonin Uptake Inhibitors

Irritable bowel syndrome is a group of symptoms that includes abdominal pain and changes in the form and frequency of stool. Since its symptoms are usually long-lasting, the disease significantly degrades quality of life. Several pharmacological therapies have been suggested according to the type of symptoms (e.g., abdominal pain, constipation, or diarrhea). In order to control abdominal pain, smooth muscle antispasmodics, antidepressants including tricyclic antidepressants and selective serotonin reuptake inhibitors, or 5-HT3 antagonists can be used. To improve constipation, dietary fiber or laxatives, 5-HT4 agonists, and chloride channel activators are available. Opioid agonists, mixed opioid agonists/antagonists such as eluxadoline, and bile salt sequestrants can be considered for diarrhea. In addition, probiotics and non-absorbable oral antibiotics can be used for the normalization of the gut microbiome and the treatment of small intestinal bacterial overgrowth, respectively. It is necessary to understand the characteristics of each drug and their combinations, because any single regimen cannot improve all symptoms in patients with irritable bowel syndrome. In this review, the mechanisms of action, efficacy, and adverse events associated with drugs used for irritable bowel syndrome are summarized.
Abdominal Pain ; Anti-Bacterial Agents ; Antidepressive Agents ; Antidepressive Agents, Tricyclic ; Bile ; Chloride Channel Agonists ; Constipation ; Diarrhea ; Dietary Fiber ; Drug Therapy* ; Gastrointestinal Microbiome ; Humans ; Irritable Bowel Syndrome* ; Laxatives ; Muscle, Smooth ; Parasympatholytics ; Probiotics ; Quality of Life ; Serotonin 5-HT3 Receptor Antagonists ; Serotonin 5-HT4 Receptor Agonists ; Serotonin Uptake Inhibitors

Serotonin syndrome is an unexpected adverse reaction of serotonergic medication. Some drugs used by anesthesiologists may cause serotonin syndrome. Serotonin syndrome is known to be related to 5-hydroxytryptamine 1A and 5-hydroxytryptamine 2A agonism. However, recent research has revealed evidence that 5-hydroxytryptamine 3 (5-HT3) antagonism can also play a role in serotonin syndrome. Among the 5-HT3 antagonists, palonosetron is the most highly specific. In this study, we present the first case of fentanyl- and meperidine-induced serotonin syndrome precipitated by palonosetron in general anesthesia.
Anesthesia, General ; Felodipine ; Fentanyl* ; Meperidine* ; Serotonin 5-HT3 Receptor Antagonists ; Serotonin Syndrome* ; Serotonin*

Chemotherapy induced nausea and vomiting (CINV) is typically biphasic. The acute phase usually peaks in 5-6 hours after the administration of chemotherapeutic agents and the delayed phase can occur subsequently over 24hours after chemotherapy. Antiemetic therapy is crucial to prevent this unwanted side effect effectively, and NK1 antagonist, 5-HT3 antagonist, corticosteroid are the main player. The combination and dosing is determined by the emetogenicity of the chemotherapeutic agents to be administrated.
Antiemetics ; Nausea ; Serotonin 5-HT3 Receptor Antagonists ; Vomiting

In the present study, extracellular recording was used to examine the neuronal activity of the basolateral nucleus (BL) of the amygdala and the effects of systemic administration of the selective 5-HT(1A) receptor antagonist WAY-100635 on the neuronal activity in the normal rats and rats with 6-hydroxydopamine (6-OHDA)-produced lesions in the substantia nigra pars compacta (SNc). The results showed that the firing rates of BL projection neurons and interneurons were (0.39±0.04) Hz and (0.83±0.16) Hz in the normal rats, and (0.32±0.04) Hz and (0.53±0.12) Hz in 6-OHDA-lesioned rats. There was no significant difference in the firing rates of BL projection neurons and interneurons between the normal and 6-OHDA-lesioned rats. In the normal rats, all BL projection neurons fired in burst; 94% of BL interneurons fired in burst and 6% fired irregularly. In 6-OHDA-lesioned rats, 85% of BL projection neurons displayed a burst firing pattern and 15% fired irregularly; 86% of BL interneurons had a burst firing pattern and 14% fired irregularly. The distribution of firing patterns of projection neurons and interneurons in the BL in 6-OHDA-lesioned rats did not differ from that in the normal rats. Systemic administration of WAY-100635 at 0.1 mg/kg body weight did not change the mean firing rates of projection neurons and interneurons in the BL in both normal and 6-OHDA-lesioned rats. However, a higher dose of WAY-100635 at 0.5 mg/kg body weight significantly decreased the mean firing rate of BL projection neurons from (0.43±0.07) to (0.15±0.02) Hz in the normal rats (P<0.01), but significantly increased the activity of BL projection neurons in 6-OHDA-lesioned rats from (0.37±0.08) to (0.69±0.18) Hz (P<0.004). The mean firing rates of BL interneurons in the normal and 6-OHDA-lesioned rats did not change after administration of a higher dose of WAY-100635 at 0.5 mg/kg body weight. These results demonstrate that the activity of BL neurons after substantia nigra dopaminergic lesion in the SNc is regulated by activation of intrinsic and extrinsic inputs, and that 5-HT(1A) receptors significantly contribute to the regulation of the activity of BL projection neurons in both normal and 6-OHDA-lesioned rats. Furthermore, WAY-100635 induced an increase in the mean firing rate of projection neurons in the BL in 6-OHDA-lesioned rats, suggesting that 5-HT(1A) receptor is likely to play a role in generating affective symptoms in Parkinson's disease.
Action Potentials ; Amygdala ; drug effects ; Animals ; Neurons ; drug effects ; Oxidopamine ; adverse effects ; Piperazines ; pharmacology ; Pyridines ; pharmacology ; Rats ; Receptor, Serotonin, 5-HT1A ; Serotonin 5-HT1 Receptor Antagonists ; pharmacology ; Substantia Nigra ; pathology

OBJECTIVEThe ventral part of the medial prefrontal cortex (mPFC) plays an important role in initiation and control of voluntary movement, mood and cognition. However, after the degeneration of the nigrostriatal pathway, the neuronal activity of the ventral mPFC and the role of serotonin(1A) (5-hydroxytryptamine, 5-HT(1A)) receptors in the firing of the neurons are still unknown. The present study is to investigate the change of neuronal activity in the ventral mPFC and the effect of systemic administration of the selective 5-HT(1A) receptor antagonist WAY-100635 on the activity of the neurons in normal and 6-hydroxydopamine (6-OHDA)-lesioned rats.

METHODSSingle unit responses were recorded extracellularly with glass microelectrodes from ventral mPFC neurons in normal rats and 6-OHDA unilaterally lesioned rats in vivo.

RESULTS6-OHDA lesion of the substantia nigra pars compacta (SNc) significantly increased the firing rate with no change in the firing pattern of neurons of the ventral mPFC in rats. Systemic administration of WAY-100635 (0.1 mg/kg, i.v.) did not change the mean firing rate and firing pattern of ventral mPFC neurons in normal rats. In contrast, WAY-100635 significantly decreased the mean firing rate of the neurons in rats with 6-OHDA lesion of the SNc.

CONCLUSIONThese data suggest that the degeneration of the nigrostriatal pathway results in an increase of neuronal activity of ventral mPFC and dysfunction of 5-HT(1A) receptor.

Action Potentials ; Animals ; Disease Models, Animal ; Male ; Neostriatum ; physiology ; Neural Pathways ; drug effects ; physiology ; physiopathology ; Neurons ; drug effects ; physiology ; Parkinson Disease ; physiopathology ; Piperazines ; pharmacology ; Prefrontal Cortex ; cytology ; drug effects ; physiology ; Pyridines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptor, Serotonin, 5-HT1A ; metabolism ; Serotonin 5-HT1 Receptor Antagonists ; Serotonin Antagonists ; pharmacology ; Substantia Nigra ; physiology

BACKGROUND: Emergence agitation is a common problem after sevoflurane anesthesia in children. Tropisetron, a 5-HT3 antagonist, significantly reduces the incidence of emergence agitation after sevoflurane anesthesia. This study evaluated the effect of ondansetron on emergence agitation after sevoflurane anesthesia in children undergoing a tonsillectomy. METHODS: Eighty children, aged 3-9 years (ASA physical status I) undergoing tonsillectomy, were randomly enrolled in this study. Group O received 0.1 mg/kg of ondansetron, and group S received 0.1 ml/kg of saline during the operation. Anesthesia was induced with 5 vol% sevoflurane and maintained with 2-2.5 vol% sevoflurane. The agitation score was recorded when they arrived at the postanesthesia care unit, and 10 minutes after that. RESULTS: The incidence of emergence agitation was 30% in group O and 27.5% in group S at arrival (P = 1.00). Ten minutes after arrival, the incidence was 12.5% in group O and 25% in group S (P = 0.25). CONCLUSIONS: Ondansetron 0.1 mg/kg does not reduce the incidence of emergence agitation after sevoflurane in children.
Anesthesia* ; Child ; Dihydroergotamine* ; Humans ; Incidence ; Ondansetron* ; Serotonin 5-HT3 Receptor Antagonists ; Tonsillectomy*