motilin and Disease-Models--Animal

Translational sciences increasingly emphasize the measurement of functions in native human tissues. However, such studies must confront variations in patient age, gender, genetic background and disease. Here, these are discussed with reference to neuromuscular and neurosecretory functions of the human gastrointestinal (GI) tract. Tissues are obtained after informed consent, in collaboration with surgeons (surgical techniques help minimize variables) and pathologists. Given the difficulties of directly recording from human myenteric neurones (embedded between muscle layers), enteric motor nerve functions are studied by measuring muscle contractions/relaxations evoked by electrical stimulation of intrinsic nerves; responses are regionally dependent, often involving cholinergic and nitrergic phenotypes. Enteric sensory functions can be studied by evoking the peristaltic reflex, involving enteric sensory and motor nerves, but this has rarely been achieved. As submucosal neurones are more accessible (after removing the mucosa), direct neuronal recordings are possible. Neurosecretory functions are studied by measuring changes in short-circuit current across the mucosa. For all experiments, basic questions must be addressed. Because tissues are from patients, what are the controls and the influence of disease? How long does it take before function fully recovers? What is the impact of age- and gender-related differences? What is the optimal sample size? Addressing these and other questions minimizes variability and raises the scientific credibility of human tissue research. Such studies also reduce animal use. Further, the many differences between animal and human GI functions also means that human tissue research must question the ethical validity of using strains of animals with unproved translational significance.

Topics: Aged; Animals; Disease Models, Animal; Electric Stimulation; Female; Gastrointestinal Diseases; Gastrointestinal Tract; Humans; In Vitro Techniques; Individuality; Intestine, Small; Male; Models, Biological; Motilin; Muscle Contraction; Muscle Relaxation; Muscle, Smooth; Neurons; Neuropharmacology; NG-Nitroarginine Methyl Ester; Peristalsis; Receptors, Serotonin; Research Design; Species Specificity; Synaptic Transmission; Translational Research, Biomedical

Topics: Afferent Pathways; Animals; Bombesin; Brain Mapping; Calcitonin; Calcitonin Gene-Related Peptide; Cholecystokinin; Corticotropin-Releasing Hormone; Disease Models, Animal; Endorphins; Feeding Behavior; Glucagon; Humans; Insulin; Motilin; Nerve Tissue Proteins; Neuropeptide Y; Neurotensin; Obesity; Pancreatic Polypeptide; Satiety Response; Somatostatin; Species Specificity; Stress, Psychological; Taste; Thyrotropin-Releasing Hormone

Topics: Animals; Bacteria; China; Disease Models, Animal; Drugs, Chinese Herbal; Dyspepsia; Feces; Female; Fruit; Gastrointestinal Microbiome; Glycation End Products, Advanced; Male; Medicine, Chinese Traditional; Motilin; Plant Extracts; Rats; Rats, Sprague-Dawley; Vasoactive Intestinal Peptide

Zinc is an important co-factor for insulin storage in pancreatic β-cells of different species and the uptake of this ion into insulin containing secretory vesicles is managed by the zinc transporter, ZnT8, a member of the slc30A gene family. Recent studies indicate that this protein is a major autoimmune target in human type 1A diabetes and has also been implicated by genome-wide association studies in type 2 diabetes. Since individuals suffering from type 1 diabetes often develop gastrointestinal motility disorders, we investigated the expression of ZnT8 in the porcine gastrointestinal tract. For this purpose, we studied the cell-type specific expression of ZnT8 in the gut and its co-expression with endocrine hormones that are closely linked to intestinal motility regulation. Nested RT-PCR and immunostaining of sequential serial sections, as well as double-immunostaining using antibodies directed against ZnT8, ghrelin, motilin, neurotensin, serotonin and glucagon-like peptide 1, indicated that ZnT8 is co-localized with ghrelin and motilin. Our findings provide important information about the cell-type specific expression of ZnT8 in the porcine gastrointestinal system. The selective and exclusive expression of ZnT8 in two endocrine cell-types that are engaged in motility functions may be of particular interest for further investigations into type I diabetes-associated gastrointestinal dysfunctions.

Topics: Animals; Cation Transport Proteins; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Disease Models, Animal; Endocrine System; Gastric Mucosa; Gastrointestinal Tract; Gene Expression Profiling; Gene Expression Regulation; Ghrelin; Immunohistochemistry; Intestinal Mucosa; Motilin; Real-Time Polymerase Chain Reaction; Swine

The pharmacological effects of glutinous rice (GR) and GR amylopectin (GRA) on the gastrointestine were investigated in rhubarb-induced spleen deficiency rats by determining the levels of gastrointestinal hormones such as the peptides serum gastrin, amylase motilin, and somatostatin. GR and GRA were given by gavage at various doses of GR (7.5, 15, and 30 g per kg body weight) and GRA (3.8, 7.6, and 15 g per kg body weight) every day for 4 weeks, respectively. The results indicated that the final body weight of rats in the highest-dose GR (GRH) group and all the GRA groups significantly (P < 0.05) increased (7.2-12.1%) compared with the model control (MC) group. All the GR and GRA treated groups had significantly (P < 0.05) higher gastrin contents (32.8-51.2%), motilin levels (13.8-39.2%), and amylase contents (22.5-39.4%) and the GRH and highest-dose GRA (GRAH) groups had significantly (P < 0.05) lower somatostatin contents compared with the MC group. Meanwhile, the somatostatin contents were negatively correlated with the motilin levels (r = -0.964, P < 0.01) and amylase contents (r = -0.981, P < 0.01). The GRAH treatment group had the highest final body weight, gastrin contents, motilin levels, and amylase contents and the lowest somatostatin contents, which demonstrated that GRA might play the most important role in the spleen-regulating activities of GR.

Topics: Amylopectin; Animals; Body Weight; Disease Models, Animal; Dose-Response Relationship, Drug; Gastrins; Male; Motilin; Oryza; Plant Extracts; Rats; Rheum; Somatostatin; Spleen

Shuidouchi (Natto) is a fermented soy product showing in vivo gastric injury preventive effects. The treatment effects of Shuidouchi fermented in different vessels on HCl/ethanol-induced gastric mucosal injury mice through their antioxidant effect was determined. Shuidouchi contained isoflavones (daidzein and genistein), and GVFS (glass vessel fermented Shuidouchi) had the highest isoflavone levels among Shuidouchi samples fermented in different vessels. After treatment with GVFS, the gastric mucosal injury was reduced as compared to the control mice. The gastric secretion volume (0.47 mL) and pH of gastric juice (3.1) of GVFS treated gastric mucosal injury mice were close to those of ranitidine-treated mice and normal mice. Shuidouchi could decrease serum motilin (MTL), gastrin (Gas) level and increase somatostatin (SS), vasoactive intestinal peptide (VIP) level, and GVFS showed the strongest effects. GVFS showed lower IL-6, IL-12, TNF-α and IFN-γ cytokine levels than other vessel fermented Shuidouchi samples, and these levels were higher than those of ranitidine-treated mice and normal mice. GVFS also had higher superoxide dismutase (SOD), nitric oxide (NO) and malonaldehyde (MDA) contents in gastric tissues than other Shuidouchi samples. Shuidouchi could raise IκB-α, EGF, EGFR, nNOS, eNOS, Mn-SOD, Gu/Zn-SOD, CAT mRNA expressions and reduce NF-κB, COX-2, iNOS expressions as compared to the control mice. GVFS showed the best treatment effects for gastric mucosal injuries, suggesting that glass vessels could be used for Shuidouchi fermentation in functional food manufacturing.

Topics: Animals; Biological Products; Biomarkers; Cytokines; Disease Models, Animal; Fermentation; Gastric Juice; Gastric Mucosa; Gastrins; Gene Expression; Glycine max; Hydrogen-Ion Concentration; Isoflavones; Malondialdehyde; Mice; Motilin; Nitric Oxide; RNA, Messenger; Somatostatin; Superoxide Dismutase; Vasoactive Intestinal Peptide

To explore the effect of modified Baizhu (Rhizoma Atractylodis Macrocephalae) powder on the gastrointestinal function in mouse models with stomach-cold functional dyspepsia. Meanwhile,the mouse models were administered with Shihu (dendrobium), a traditional Chinese drug with cold nature and flavour, to explore the way via which it exert its effect on specific symptoms. Methods: Mouse models with stomach-cold functional dyspepsia were established by ice water and ice NaOH. The effects of modified Baizhu powder and dendrobium on mice were observed in terms of water intake, weight change,small intestine propulsion rate, intestinal absorption function, and effects on ghrelin and motilin.. The modified Baizhu powder effectively increased food intake, water intake, body weight (P<0.05) and swimming time (P<0.01), increased the small intestine propulsion rate and serum D-xylose content (P<0.05), and up-regulated ghrelin (P<0.05). Also, it showed a trend to down-regulate the motilin, although the change was not statistically significant (P>0.05). In contrast,the use of Shihu aggravated symptoms in the mouse models. Conclusion: The changes in ghrelin and motilin levels may be the neuro-endocrine mechanisms via which the modified Baizhu powder and Shihu exert their effects on mouse models.

Topics: Animals; Disease Models, Animal; Dyspepsia; Ghrelin; Intestine, Small; Medicine, Chinese Traditional; Mice; Motilin; Powders; Stomach

To investigate the effects of intrathecal morphine and fentanyl combined with low-dose naloxone on the expression of motilin and its receptor in a rat model of postoperative pain.. An intrathecal catheter was implanted, and saline, opioids (morphine and fentanyl) and naloxone were intrathecally administered 7 days later. An incisional pain model was established to induce pain behaviors in rats by unilateral plantar incision. Thermal hyperalgesia and mechanical allodynia were measured by using a radiant heat and electronic Von Frey filament, respectively. The expression of motilin in the hippocampus, stomach, duodenum, and plasma was determined by ELISA; and the expression of motilin receptor in the hippocampus was detected by Western blot assay.. Motilin and its receptor were detected in the hippocampus. Acute incisional pain increased the motilin expression in the hippocampus and duodenum, while decreasing its expression in the gastric body and plasma. Postoperative analgesia with morphine+fentanyl upregulated the expression of motilin in the hippocampus; however, motilin was downregulated in peripheral sites. Naloxone at 1 ng/kg restored motilin to baseline levels. Acute pain, morphine+fentanyl, and naloxone all induced the expression of motilin receptor in the hippocampus.. Acute pain, postoperative analgesia with opioids, and naloxone significantly impacted the expression of hippocampal and peripheral motilin. Variation trends in all sites were not identical. Intrathecal injection of low-dose naloxone upregulated paw withdrawal thermal latency and enhanced the analgesic effects of opioids. The findings presented here provide a new basis for central and peripheral regulations in GI motility, clinical postoperative analgesia, and management of analgesic complications.

Topics: Analgesics, Opioid; Animals; Disease Models, Animal; Drug Therapy, Combination; Hippocampus; Injections, Spinal; Motilin; Naloxone; Pain Measurement; Pain, Postoperative; Rats; Rats, Sprague-Dawley; Receptors, Gastrointestinal Hormone; Receptors, Neuropeptide; Treatment Outcome; Up-Regulation

Paradoxically, erythromycin is associated with nausea when used as an antibiotic but at lower doses erythromycin activates motilin receptors and is used to treat delayed gastric emptying and nausea. The aim of this study was to characterise pro- and anti-emetic activity of erythromycin and investigate mechanisms of action. Japanese House musk shrews (Suncus murinus) were used. Erythromycin was administered alone or prior to induction of emesis with abnormal motion or subcutaneous nicotine (10mg/kg). The effects of erythromycin and motilin on vagal nerve activity and on cholinergically mediated contractions of the stomach (evoked by electrical field stimulation) were studied in vitro. The results showed that erythromycin (1 and 5mg/kg) reduced vomiting caused by abnormal motion (e.g., from 10.3 ± 1.8 to 4.0 ± 1.1 emetic episodes at 5mg/kg) or by nicotine (from 9.5 ± 2.0 to 3.1 ± 2.0 at 5mg/kg), increasing latency of onset to emesis; lower or higher doses had no effects. When administered alone, erythromycin 100mg/kg induced vomiting in two of four animals, whereas lower doses did not. In vitro, motilin (1, 100 nM) increased gastric vagal afferent activity without affecting jejunal afferent mesenteric nerve activity. Cholinergically mediated contractions of the stomach (prevented by tetrodotoxin 1 μM or atropine 1 μM, facilitated by l-NAME 300 μM) were facilitated by motilin (1-100 nM) and erythromycin (10-30 μM). In conclusion, low doses of erythromycin have anti-emetic activity. Potential mechanisms of action include increased gastric motility (overcoming gastric stasis) and/ or modulation of vagal nerve pathways involved in emesis, demonstrated by first-time direct recording of vagal activation by motilin.

Topics: Animals; Antiemetics; Disease Models, Animal; Dose-Response Relationship, Drug; Electric Stimulation; Erythromycin; Female; Gastric Mucosa; Gastrointestinal Agents; Gastrointestinal Motility; Male; Motilin; Muscle Contraction; Nicotine; Receptors, Gastrointestinal Hormone; Receptors, Neuropeptide; Shrews; Stomach; Vagus Nerve; Vomiting

To investigate the effect of Simotang (Decoction of Four Powered Drugs) on gastrointestinal motility, motilin and cholecystokinin expression in chronically stressed mice.. Forty mice were randomly divided into control group, stress group (model group), mosapride group and Simotang group, 10 in each group. A variety of unpredictable stimulations were used to induce chronic stress in mice. Then, the mice were treated with distilled water, mosapride or Simotang for 7 d. Gastric emptying and intestinal propulsion function were detected. Serum level of motilin was measured by enzyme-linked immunosorbent assay. Expression of cholecystokinin (CCK) in intestine, spinal cord and brain of mice was detected by immunohistochemistry and semi-quantitative reverse transcription polymerase chain reaction, respectively.. Simotang improved the gastric emptying and intestinal propulsion in chronically stressed mice. Furthermore, the serum motilin level was significantly higher and the expression levels of CCK-positive cells and genes were significantly lower in intestine, spinal cord and brain of Simotang group than in those of model group (P < 0.05). No significant difference was found in serum motilin level and expression levels of CCK-positive cells and genes between the mosapride and Simotang groups.. Simotang enhances the gastrointestinal motility in chronically stressed mice by regulating the serum motilin level and the expression of cholecystokinin.

Topics: Animals; Benzamides; Brain; Cholecystokinin; Disease Models, Animal; Drugs, Chinese Herbal; Enzyme-Linked Immunosorbent Assay; Gastrointestinal Agents; Gastrointestinal Motility; Immunohistochemistry; Intestine, Small; Male; Mice; Mice, Inbred ICR; Morpholines; Motilin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spinal Cord; Stress, Psychological

The effects of mitemcinal (GM-611), an orally active motilin agonist, on defecation were investigated in rabbits and dogs. In normal rabbits, within 0-3 h of dosing, orally administered mitemcinal (2.5-10 mg kg(-1)) increased stool weight in a dose-dependent manner without causing loose stools. Sennoside (12-48 mg kg(-1)) also facilitated defecation within 2-9 h of oral administration, but the stools were significantly loosened. In the morphine-induced constipation model, the stool weight of morphine-treated rabbits (1 mg kg(-1)) was only 37.5% of that of untreated animals. Mitemcinal (0.5-20 mg kg(-1)) dose-dependently increased stool weight without increasing stool water content. At the highest dose of mitemcinal, stool weight recovered to 83.9% of that of untreated animals. In normal dogs, mitemcinal (0.3-3 mg kg(-1)) reduced the time to first bowel movement after oral administration without inducing diarrhoea at any dose. These results indicate that mitemcinal facilitates defecation without inducing severe diarrhoea. It is suggested that mitemcinal may be a novel therapeutic agent for constipation that enables easier control of the timing of defecation because of the early onset and short duration of its action, compared with sennoside.

Topics: Animals; Constipation; Defecation; Diarrhea; Disease Models, Animal; Dogs; Dose-Response Relationship, Drug; Erythromycin; Gastrointestinal Agents; Morphine; Motilin; Rabbits; Reference Values

To investigate the effects of surface gastric pacing on gastric myoelectrical activity and plasma motilin concentration in a canine model of gastric motility disorders.. Ten healthy mongrel dogs were divided into two groups: an experimental group of six dogs and control group of four dogs. The model of gastric motility disorders was established in the experimental group with truncal vagotomy combined with injection of glucagon. Gastric serosal myoelectrical activity was recorded with a four-channel computer analysis device. Plasma motilin concentration was measured with a radioimmunoassay (RIA) kit. Surface gastric pacing at 1.1-1.2-fold the intrinsic slow-wave frequency superimposed with a series of high frequency pulses (10-30 Hz) was performed for 45 min daily for 1 month in the conscious dogs.. The basic electrical rhythm (BER) amplitude (2.32 +/- 0.35 mV) and propagation velocity (4.06 +/- 0.40 cm/s) of the dogs with bilateral truncal vagotomy in the fed state decreased more significantly than those of the controls (4.25 +/- 0.12 mV, 6.92 +/- 0.24 cm/s) (P < 0.03). After long-term surface gastric pacing, the BER amplitude (3.97 +/- 0.19 mV) and propagation velocity (5.57 +/- 0.48 cm/s) was increased significantly compared with before pacing (P < 0.05). Postprandial gastric dysrhythmias were provoked by large doses of glucagon; the percentage of regular slow waves of the dogs with vagotomy was markedly reduced from 67.4 +/- 6.2% at baseline to 10.0 +/- 6.7% (P < 0.001), and that of the control was also decreased from 87.1 +/- 6.9% to 35.0 +/- 11.0% (P < 0.01), but the entrainment of gastric slow waves was 100% by means of gastric pacing at optimal parameters. There was a significant increase in the plasma concentration of motilin at the phase III of the interdigestive myoelectrical complex (IMC III) in the dogs with bilateral truncal vagotomy (baseline vs vagotomy, 184.29 +/- 9.81 pg/mL vs 242.09 +/- 17.22 pg/mL; P< 0.01). However, the plasma motilin concentration (212.55 +/- 11.20 pg/mL; P < 0.02) was decreased significantly after long-term gastric pacing. Before gastric pacing the plasma motilin concentration showed an equally negative correlation with the BER amplitude, and propagation velocity in the dogs with vagotomy in the fed state (r = -0.473, r = -0.807, P < 0.04), but after long-term gastric pacing, the plasma motilin concentration showed an equally positive correlation with the BER amplitude and propagation velocity (r = 0.523, r = 0.896, P < 0.02).. Surface gastric pacing with optimal pacing parameters is able to entrain completely propagated slow waves, improve the parameters of gastric myoelectrical activity and normalize gastric dysrhythmias induced by a pharmacological agent. Surface gastric pacing might be useful in the treatment of gastric dysrhythmia. The gastric myoelectrical activity correlated well with the plasma motilin concentration before and after pacing, which suggests that motilin could modulate the effect of gastric pacing through alteration of the gastric myoelectrical parameters.

Topics: Animals; Disease Models, Animal; Dogs; Electric Stimulation; Fasting; Female; Gastrointestinal Motility; Glucagon; Male; Motilin; Stomach

The effects of SK-896, a new human motilin analogue ([Leu13]motilin-Hse), on digestive tract motility in postoperative ileus were evaluated in a dog model of ileus after laparotomy. SK-896 was intravenously administered at 0.17, 0.33 and 0.67 microg/kg starting soon after operation and then at 6-h intervals, for a total of 9 times. SK-896 progressively, dose-dependently and significantly increased the duodenal motility from 1 h after operation. The recovery time of the gastrointestinal-interdigestive migrating complex (GI-IMC) activity, which is an indicator of normal gastrointestinal tract activity after laparotomy, was 56.5 +/- 5.0 h in the control group. SK-896 significantly shortened this recovery time. On the other hand, the plasma SK-896 concentrations declined diexponentially after administration, and can be described by a linear pharmacokinetic model within the dose range used. In addition, the pharmacokinetics of SK-896 did not change significantly at any postoperative time. There was no correlation between the plasma SK-896 concentrations and the intensity of duodenal motility, because the activity in the duodenum decreased transiently 13 h after laparotomy and increased with time thereafter. The changes in the activity are considered to reflect the progressive changes in the state of ileus. In conclusion, SK-896 increased the duodenal motility significantly, shortening the recovery time of GI-IMC-like activity in dogs with post-laparotomy ileus. Therefore, it is expected from these results that SK-896 would be useful and effective for the treatment of gastroparalysis after abdominal surgery.

Topics: Animals; Disease Models, Animal; Dogs; Gastrointestinal Motility; Humans; Injections, Intravenous; Intestinal Obstruction; Laparotomy; Male; Motilin; Postoperative Complications

To investigate the changes of gastrin, somatostatin and motilin production in the gastric antral mucosa of rats with experimental gastric ulcer.. Rat models of gastric ulcer model were induced successfully by injection of acetic acid into the gastric antral wall of 2 groups of Wistar rats (7 in each group) that were subjected to environment of either high or normal temperature. Another 2 groups of rats (n=7) receiving normal saline injection in the same manner, along with still another 2 groups (n=7) without any treatment, all of which were kept under conditions with different temperatures accordingly, constituted the control groups. The levels of gastrin, somatostatin and motilin in the gastric antral mucosa of the rats were measured with radioimmunoassay.. In rats with gastric ulcer, the levels of gastrin and motilin in the antral mucosa increased, but in a lesser scale in rats with ulcer kept in high temperature than in normal temperature group, while that of somatostatin was reduced. The level of somatostatin declined less in the high temperature group with ulcer than in the normal temperature group with ulcer.. High temperature can affect gastrin, somatostatin and motilin production in the gastric antral mucosa of rats with gastric ulcer.

Topics: Animals; Disease Models, Animal; Gastric Mucosa; Gastrins; Male; Motilin; Pyloric Antrum; Rats; Rats, Wistar; Somatostatin; Stomach Ulcer; Temperature

A novel peptide called ghrelin or motilin-related-peptide (MTLRP) was found in the stomach of various mammals. We studied its effect on the motor function of the rat gastrointestinal tract. In normal, conscious unoperated animals, ghrelin/MTLRP (5 or 20 microg/kg iv) significantly accelerated the gastric emptying of a methylcellulose liquid solution (gastric residue after 15 min: 57 +/- 7, 42 +/- 11, 17 +/- 4, and 9 +/- 3% of the ingested meal with doses of 0, 1, 5, and 20 microg/kg iv, respectively) Transit of the methylcellulose liquid solution was also accelerated by ghrelin/MTLRP in the small intestine but not in the colon. Des-[Gln(14)]ghrelin, also found in the mammalian stomach, was as potent as ghrelin in emptying the stomach (gastric residue after 15 min: 12 +/- 3% at a dose of 20 microg/kg iv). In rats in which postoperative gastrointestinal ileus had been experimentally induced, ghrelin/MTLRP (20 microg/kg iv) reversed the delayed gastric evacuation (gastric residue after 15 min: 28 +/- 7% of the ingested meal vs. 82 +/- 9% with saline). In comparison, the gastric ileus was not modified by high doses of motilin (77 +/- 7%) or erythromycin (82 +/- 6%) and was only partially improved by calcitonin gene-related peptide (CGRP) 8-37 antagonist (59 +/- 7%). Ghrelin/MTLRP, therefore, accelerates the gastric emptying and small intestinal transit of a liquid meal and is a strong prokinetic agent capable of reversing the postoperative gastric ileus in rat.

Topics: Animals; Colon; Disease Models, Animal; Dose-Response Relationship, Drug; Gastric Emptying; Gastrointestinal Motility; Ghrelin; Intestinal Obstruction; Intestine, Small; Male; Motilin; Peptide Hormones; Peptides; Postoperative Complications; Rats; Rats, Sprague-Dawley

Very few phase III activity of the interdigestive migrating contractions (phase III) occurs in the stomach of fasted duodenal ulcer patients. But the mechanism is not well understood. In this study, we studied the effect of gastric and duodenal acidification on the spontaneous phase III activity in the upper gastrointestinal tract of conscious dogs. Gastric and duodenal motor activity in 5 conscious dogs was monitored by means of chronically implanted force transducers. Intragastric pH changes were measured by placing a pH glass electrode in the gastric antrum. Intragastric and intraduodenal acidification was achieved by i.v. infusion of histamine, and by intragastric and intraduodenal instillation of acidic solutions of different pHs. The plasma motilin concentrations were measured by radioimmunoassay. Histamine (40 micrograms/kg/h) inhibited spontaneous phase III activity, but the histamine-induced inhibition was completely prevented by pretreatment with famotidine, a potent histamine H2 receptor antagonist (0.3 mg/kg, i.v.). Intragastric acidification at pH 1.0 strongly inhibited spontaneous phase III activity, but an acidic solution at pH 2.0 had no effect in inhibiting phase III activity. Intraduodenal acidification at pH 1.0 also inhibited spontaneous phase III activity. Histamine injection and gastric and duodenal acidification at pH 1.0 strongly suppressed motilin release. It is concluded that gastric and duodenal acidification at pH 1.0 inhibits the occurrence of the spontaneous phase III activity, and the suppression of endogenous release of motilin due to gastric and duodenal acidification at pH 1.0 is involved in this inhibitory mechanism.

Topics: Animals; Disease Models, Animal; Dogs; Duodenal Ulcer; Electrodes; Electrophysiology; Famotidine; Female; Gastric Acid; Gastrointestinal Motility; Histamine; Hydrogen-Ion Concentration; Male; Motilin; Muscle Contraction; Muscle, Smooth; Stomach Ulcer