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The American Journal of Physiology Jan 1998The effect of motilin on insulin release has not been studied in the interdigestive state. Adult mongrel dogs were chronically implanted with force transducers in the...
The effect of motilin on insulin release has not been studied in the interdigestive state. Adult mongrel dogs were chronically implanted with force transducers in the stomach and duodenum to monitor contractile activity, and the plasma motilin and insulin concentrations were measured by a specific radioimmunoassay and enzyme immunoassay, respectively. The concentration of insulin in plasma was found to fluctuate in close association with that of motilin and phase III of the interdigestive migrating contractions in the stomach. This spontaneous release of insulin was mimicked by intravenous infusion of motilin at a dose of 0.3 microgram.kg-1.h-1. Exogenous motilin (0.01-0.3 microgram/kg) dose dependently stimulated insulin release, which was abolished by atropine, hexamethonium, ondansetron, and truncal vagotomy. Phentolamine significantly enhanced, whereas propranolol inhibited, motilin-induced insulin release. In a perifusion system using islet cells from the canine pancreas, motilin did not affect insulin release. In conclusion, motilin stimulates insulin release through vagal cholinergic, muscarinic receptors on pancreatic beta-cells, and the effect appears to be modulated by adrenergic nerves.
Topics: Activity Cycles; Animals; Atropine; Blood Glucose; Digestion; Dogs; Duodenum; Fasting; Hexamethonium; Insulin; Insulin Secretion; Islets of Langerhans; Motilin; Myoelectric Complex, Migrating; Ondansetron; Phentolamine; Receptors, Muscarinic; Stomach; Time Factors; Vagotomy; Vagus Nerve
PubMed: 9458777
DOI: 10.1152/ajpgi.1998.274.1.G87 -
Gut May 1978Motilin is found in the upper intestine of pig and man and in man is released by acid. A similar release by acid has now been found in the pig and is associated with...
Motilin is found in the upper intestine of pig and man and in man is released by acid. A similar release by acid has now been found in the pig and is associated with markedly reduced immunostainable motilin in the upper small intestine. Clamping the arteries and veins to the stimulated segment immediately reversed the rise of plasma motilin, indicating the motilin release to be an entirely local phenomenon. The apparent half life of endogenous motilin was 3.9 minutes. No release of motilin was seen after a meal and the possible physiological role of motilin thus remains speculative.
Topics: Animals; Gastrointestinal Hormones; Hydrochloric Acid; Intestine, Small; Motilin; Secretory Rate; Swine
PubMed: 658771
DOI: 10.1136/gut.19.5.399 -
Gut Jun 1998Animal studies have shown that motilin affects gall bladder motility. In humans, no effect has been shown, but erythromycin, a motilin receptor agonist, induces gall... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
BACKGROUND
Animal studies have shown that motilin affects gall bladder motility. In humans, no effect has been shown, but erythromycin, a motilin receptor agonist, induces gall bladder emptying.
AIMS
To explore the effect of increasing doses of exogenous motilin on gall bladder volume and antral contractility in the fasted state in humans.
METHODS
After an overnight fast, eight healthy men received increasing intravenous doses of Leu13-motilin (KW-5139) or 0.9% NaCl in a double blind, randomised fashion. Gall bladder volume and antral contraction frequency were determined by ultrasonography.
RESULTS
Infusion of motilin increased plasma motilin levels. Motilin induced a reduction in gall bladder volume of 8.0 (5.0)%, 17.1 (5.0)%, 18.5 (4.7)%, and 16.1 (4.9)% of baseline volume at the end of infusion of 2, 4, 8, and 16 pmol/kg/min respectively, compared with mean stable gall bladder volumes during placebo infusion (p < 0.05). Antral contraction frequency increased during motilin infusion, but not during placebo infusion (p < 0.05).
CONCLUSIONS
Exogenous motilin reducted fasting gall bladder volume and increased antral contractions. After reaching maximal reduction, the gall bladder volume did not decrease further during continuous motilin infusion at higher doses and stayed at the same reduced volume. The degree of gall bladder volume reduction during motilin infusion mimicked gall bladder emptying preceding antral phase III activity of the migrating motor complex in humans. This study indicates that motilin may play a physiological role in the regulation of gall bladder emptying in the fasted state.
Topics: Adult; Cross-Over Studies; Double-Blind Method; Fasting; Gallbladder; Gallbladder Emptying; Gastric Emptying; Humans; Male; Motilin; Pyloric Antrum; Ultrasonography
PubMed: 9691922
DOI: 10.1136/gut.42.6.830 -
Neurogastroenterology and Motility Jan 2006
Topics: Animals; Gastrointestinal Agents; Gastrointestinal Motility; Gastrointestinal Transit; Humans; Motilin; Peptide Fragments; Tachyphylaxis
PubMed: 16371077
DOI: 10.1111/j.1365-2982.2005.00749.x -
Gastroenterology Nov 2017
Topics: Biomedical Research; Europe; Gastric Inhibitory Polypeptide; Gastroenterology; History, 20th Century; History, 21st Century; Motilin; North America; Paintings
PubMed: 28988915
DOI: 10.1053/j.gastro.2017.09.037 -
European Journal of Anaesthesiology Jan 1997
Topics: Animals; Erythromycin; Gastric Emptying; Gastrointestinal Agents; Gastrointestinal Motility; Humans; Motilin
PubMed: 9049551
DOI: 10.1046/j.1365-2346.1997.00972.x -
Gastroenterology Sep 1985The lower esophageal sphincter (LES) exhibits cyclical phasic contractile activity synchronous with phases II and III of the gastric migrating motor complex. Motilin has... (Comparative Study)
Comparative Study
The lower esophageal sphincter (LES) exhibits cyclical phasic contractile activity synchronous with phases II and III of the gastric migrating motor complex. Motilin has been implicated in this process, although the exact mechanism is unknown. The effect of motilin on LES pressure and on gastrointestinal myoelectric activity was examined in 8 unanesthetized opossums. Intraluminal pressure was recorded by a manometric assembly incorporating a sleeve device. Myoelectric activity was recorded from the stomach, duodenum, and jejunum via implanted electrodes. The opossum LES exhibited cyclical periods of phasic contractions synchronous with phases II and III of the gastric migrating motor complex cycle. Variations in the occurrence and magnitude of the phasic LES pressure waves paralleled the spontaneous cyclic fluctuations in the level of circulating plasma motilin. Pulse doses of exogenous motilin (25-400 ng/kg) elicited a contractile LES response that mimicked the spontaneous migrating motor complex-related phasic LES contractions. This effect was dose related with the maximal response occurring at a motilin dose of 100 ng/kg. The LES response to motilin was abolished by hexamethonium and significantly antagonized by atropine and 4-diphenylacetoxy-N-methylpiperidine methiodide, but was not affected by pirenzepine, phentolamine, or naloxone. The study findings support the hypothesis that cyclic increases in circulating endogenous motilin incorporate phasic LES as well as gastric contractile activity into the gastrointestinal migrating motor complex cycle. Motilin acts on the LES by the preganglionic stimulation of cholinergic nerves.
Topics: Action Potentials; Animals; Dose-Response Relationship, Drug; Electromyography; Esophagogastric Junction; Fasting; Gastrointestinal Hormones; Manometry; Motilin; Muscle Contraction; Opossums
PubMed: 4018497
DOI: 10.1016/0016-5085(85)90444-5 -
Nihon Shokakibyo Gakkai Zasshi = the... Aug 1996
Review
Topics: Amino Acid Sequence; Animals; Gastrointestinal Diseases; Gastrointestinal Motility; Humans; Molecular Sequence Data; Motilin
PubMed: 8810808
DOI: No ID Found -
FEBS Letters Jun 2003The interaction between the peptide hormone motilin and bicelles has been investigated by pulsed field gradient-nuclear magnetic resonance methods and by the use of... (Comparative Study)
Comparative Study
The interaction between the peptide hormone motilin and bicelles has been investigated by pulsed field gradient-nuclear magnetic resonance methods and by the use of paramagnetic probes. Diffusion coefficients were measured for motilin, the phospholipids with and without motilin, and for tetramethylsilane. The results show that around 90% of motilin is bound to acidic bicelles and 84% of motilin is bound to neutral bicelles. It is found that the apparent bicelle size is reduced by the presence of motilin. This cannot be explained by changes in 1,2-dihexanoyl-sn-glycero-3-phosphatidylcholine solubility. The use of paramagnetic agents to investigate the position of motilin shows that the turn in the N-terminus of motilin is inserted into the bicelle, while the helix most likely resides within the head-group layer.
Topics: Circular Dichroism; Diffusion; Electron Spin Resonance Spectroscopy; Hydrogen-Ion Concentration; Lipid Bilayers; Membrane Lipids; Models, Molecular; Motilin; Nuclear Magnetic Resonance, Biomolecular; Phospholipids; Silanes; Solutions; Trimethylsilyl Compounds
PubMed: 12804764
DOI: 10.1016/s0014-5793(03)00514-3 -
Scandinavian Journal of... 1976
Topics: Amino Acid Sequence; Animals; Dogs; Gastrointestinal Hormones; Gastrointestinal Motility; History of Medicine; Motilin
PubMed: 792982
DOI: No ID Found