Antral Motility Research Articles

Changes in cardiovascular performance, biochemistry, gastric motility and muscle temperature induced by acute exercise on a treadmill in healthy military dogs.

Changes in physiological parameters that are induced by acute exercise on a treadmill in healthy military dogs have not been thoroughly investigated, especially with regard to age. This study investigated the effects of acute exercise on a treadmill on cardiovascular function, biochemical parameters and gastric antral motility in military dogs. Thermography was used to assess variations in superficial hindlimb muscle temperature. Nine healthy dogs were distributed into three groups according to their age (Group I: 25±7months; Group II: 51±12months; Group III: 95±10months) and sequentially subjected to running exercise on a treadmill for 12min (3.2km/h at 0° incline for 4min, 6.4km/h at 0° incline for 4min and 6.4km/h at 10° incline for 4min). Heart rate, systolic and diastolic arterial pressure (DAP), gastric motility, haematocrit and biochemical analyses were performed at rest and after each session of treadmill exercise. Infrared thermographic images of muscles in the pelvic member were taken. Exercise decreased DAP in Group I, increased systolic arterial pressure in Groups II and III and increased mean arterial pressure in Group III (all p<0.05). After the exercise protocol, plasma creatine kinase and aspartate aminotransferase levels increased only in Group I (p<0.05). Exercise increased heart rate and decreased the gastric motility of a solid meal at 180min in all groups (all p<0.05). Exercise also elevated temperature in the femoral biceps muscles in Group I compared with the older dogs. The results indicate that acute exercise decreased gastric motility in dogs, regardless of age, and caused more pronounced cardiovascular changes in older dogs than in younger dogs. Acute exercise also altered biochemical parameters and superficial hindlimb muscle temperature in younger military dogs.

Effects of ghrelin receptor agonist, relamorelin, on gastric motor functions and satiation in healthy volunteers.

Synthetic human ghrelin accelerates gastric emptying, reduces gastric accommodation, and results in numerical increases in postprandial symptom scores. The ghrelin receptor agonist, relamorelin, accelerates gastric emptying in patients with diabetic gastroparesis. To measure pharmacological effects of relamorelin on gastric accommodation, distal antral motility, and satiation in healthy volunteers. In a placebo-controlled, double-blind, randomized study of 16 healthy volunteers, we compared effects of 30 μg subcutaneous (s.c.) relamorelin to placebo on: (i) gastric volumes measured by single photon emission computed tomography, (ii) 1-h postprandial distal antral motility index (MI) by 15-lumen perfusion gastroduodenal manometry, and (iii) satiation tested by Ensure nutrient drink test. Primary endpoints were: fasting and postprandial gastric volumes, distal antral phasic pressure activity (number of contractions, mean amplitude, and MI), and maximum tolerated volume. Results were normally distributed and the two treatment groups were compared using t-test. Relamorelin, 30 μg s.c., significantly increased the number of contractions in the distal antrum during 0-60 min postmeal when compared to placebo (p = 0.022); this was also observed in the first two 15-min periods (p = 0.005 and 0.015 for number of contractions 0-15 and 16-30). There was borderline increase in MI0-15 (p = 0.055) and numerically increased MI0-60 (p = 0.139) and MI16-30 (p = 0.116). The amplitude of contractions was not significantly increased. Relamorelin did not significantly alter fasting or postprandial gastric volumes, gastric accommodation, or satiation volumes and symptoms. Relamorelin increases frequency of distal antral motility contractions without significant effects on amplitude of contractions. The lack of inhibition of accommodation and absence of increase in satiation symptoms support relamorelin for the treatment of symptomatic gastroparesis (ClinicalTrials.gov NCT02466711).

Effect of DA-9701 on the Normal Motility and Clonidine-induced Hypomotility of the Gastric Antrum in Rats.

Background/AimsDA-9701 is a novel prokinetic agent. In the present study, we investigated the effect of DA-9701 on the motility of the gastric antrum in the normal and clonidine-induced hypomotility in an in vivo animal model.MethodsA strain gauge force transducer was sutured on the gastric antrum to measure the contractile activity in rats. A total of 28 rats were subclassified into the 4 groups: (1) the placebo group, (2) the DA-9701 group, (3) the placebo group in the clonidine-pretreated rats, and (4) the DA-9701 group in the clonidine-pretreated rats. After the basal recording, either placebo (3% [w/v] hydroxypropylmethyl cellulose) or DA-9701 was administered. Contractile signals were measured after the administration and after a meal. In the clonidine-pretreated rats, either placebo or DA-9701 was administered. Contractile signals were measured after the administration and after a meal.ResultsOral administration of DA-9701 did not significantly alter the motility index of the gastric antrum in the preprandial and postprandial periods, compared with the placebo group. The administration of clonidine decreased the motility index of the gastric antrum in the preprandial and postprandial periods, compared with the administration of placebo. This reduction of the antral motility by the administration of clonidine was not observed in the clonidine-pretreated DA-9701 group. The percentage of the motility index in the postprandial period was significantly greater in the clonidine-pretreated DA-9701 group, compared with the clonidine-pretreated placebo group.ConclusionsDA-9701 improves the hypomotility of the gastric antrum induced by clonidine, suggesting its gastroprokinetic effect in the pathologic condition.

Mo1614 Simultaneous Assessment of Gastric Motor Function by Dynamic Antral Scintigraphy (DAS) and Wireless Motility Capsule (WMC) in Gastroparetic Patients

Mo1614 Simultaneous Assessment of Gastric Motor Function by Dynamic Antral Scintigraphy (DAS) and Wireless Motility Capsule (WMC) in Gastroparetic Patients

Abdominal migraine in children: association between gastric motility parameters and clinical characteristics.

BackgroundApproximately 0.2–1 % of children suffers from abdominal migraine (AM). Pathophysiology of AM has not been adequately studied. This study evaluated gastric motility in children with AM.MethodsSeventeen children (6 boys), within an age range of 4–15 years, referred to a tertiary care paediatric unit, North Colombo Teaching Hospital Ragama, Sri Lanka, from 2007 to 2012, were screened. Those fulfilling Rome III criteria for AM were recruited after obtaining parental consent. None had clinical or laboratory evidence of organic disorders. Twenty healthy children (8 boys), with an age range of 4–14 years, were recruited as controls. Liquid gastric emptying rate (GE) and antral motility parameters were assessed using an ultrasound method.ResultsAverage GE (41.6 % vs. 66.2 %, in controls), amplitude of antral contractions (A) (57.9 % vs. 89.0 %) and antral motility index (MI) (5.0 vs. 8.3) were lower and fasting antral area (1.8 cm2 vs. 0.6 cm2) was higher in children with AM (p < 0.01). No significant difference in the frequency of antral contractions (F) (8.8/3 min vs. 9.3/3 min, p = 0.08) was found between the two groups. Scores obtained for severity of abdominal pain had a negative correlation with A (r = −0.55, p = 0.03). Average duration of abdominal pain episodes correlated with GE (r = −0.58, p = 0.02). Negative correlations were observed between duration of AM and A (r = −0.55), F (r = −0.52), and MI (r = −0.57) (p < 0.05).ConclusionsGE and antral motility parameters were significantly lower in children with AM. A significant correlation was found between symptoms and gastric motility. These findings suggest a possible role of abnormal gastric motility in the pathogenesis of AM.

PP‐14 EFFECTS OF BODY MASS INDEX ON GASTRIC MOTILITY IN CHILDREN WITH ABDOMINAL PAIN‐PREDOMINANT FUNCTIONAL GASTROINTESTINAL DISORDERS

Introduction:There is evidence that overweight children have a higher prevalence of functional gastrointestinal disorders (FGIDs) than normal‐weight children. Objective of this study was to assess the effects of body mass index (BMI) on gastric motility abnormalities in children with abdominal pain‐predominant FGIDs (AP‐FGIDs).Methods:Gastric motility parameters of 100 children with AP‐FGIDs (61(61%) girls, mean age 8.0 years [SD 2.1years] and 50 healthy controls (30 (30%) boys, mean age 8.6 years [SD 1.9 years]) were assessed at the Gastroenterology Research Laboratory of Faculty of Medicine, University of Kelaniya, Sri Lanka, using a previously validated ultrasound method. AP‐FGIDs were diagnosed using Rome III criteria. Fifty‐four had functional abdominal pain, 23 had irritable bowel syndromes, 9 had functional dyspepsia, 8 had abdominal migraine and 6 had more than one AP‐FGID.Results:Patients with AP‐FGIDs had significantly lower gastric emptying rate (44.9% vs. 59.5% in controls, p &lt; 0.0001), frequency of antral contractions (8.29 vs. 9.44, p &lt; 0.0001), amplitude of antral contraction (48.6% vs. 58.1%, p &lt; 0.0001) and antral motility index (4.0 vs. 6.4, p = 0.001). Fasting antral size (FA) and antral area at 1minute (AA1) and antral area at 15 minutes (AA15) after ingestion of the liquid test meal were not significantly different. BMI of children with AP‐FGIDs and controls were respectively 15.2 and 15.6 (p = 0.42). The correlations between BMI and AA1 (r = 0.29, p = 0.007), AA15 (r = 0.32, p = 0.003) and MI (r = 0.22, p = 0.038) in children with AP‐FGIDs were significant. Patients with BMI &lt;15Kg/m2 had a lower FA (1.5cm2 vs. 2.1cm2, p = 0.03), AA1 (8.9 cm2 vs. 10.7 cm2, p = 0.003) and AA15 (4.6 cm2 vs. 5.8 cm2, p = 0.01) than patients with BMI &gt;15Kg/m2.Conclusions:BMI has an impact on certain gastric motility parameters in children with AP‐FGIDs. However, it does not contribute to abnormalities seen in main gastric motility parameters such as gastric emptying.

Su1452 Analyses of Long-Term Follow-Up of Gastric Electrical Stimulation Therapy and Pyloroplasty for Refractory Gastroparesis

G A A b st ra ct s amplitude of antral contractions Luminal obliteration Motility index Characterize antral contractility and identify its role in patients with rapid gastric emptying (RGE) and delayed gastric emptying (DGE). Describe antral contractility patterns in patients with UGIMD and normal gastric emptying (NGE) and role in explaining symptoms. METHODS Age, clinical presentation, gender, diabetes mellitus, other comorbidities, and ethnicity were documented in 10 patients who underwent GES and DAS from October to November of 2014. All patients ingested a standardized low-fat meal (255 kCal) labeled with 2 mCi of Tc-99m SC, obtaining 1-minute static images in the anterior and posterior projections at 30, 60, 120, 180 and 240 minutes. The DAS methodology involved 512 dynamic images at 0.5 second per frame acquired in the anterior projection at 15, 30, 45, 60, 90, 180 and 240 minutes. The data was analyzed to derive the following mean parameters of antral motility: a) Frequency, rhythm, coordination and amplitude of contractions, representing the cyclic variation of labeled meal, b) Obliteration or fraction of labeled meal that leaves the antrum during each contraction and c) Motility index or fraction of contents leaving the antrum per minute (product of obliteration and frequency). RESULTS The mean age was 53 years (21-67), 8 females, 3 had diabetes mellitus. Two patients with DGE (1 diabetic and 1 idiopathic) had the highest contraction frequency, but the lowest contraction amplitude, obliteration and motility index (Fig. 1). Two patients with RGE (1 diabetic and 1 idiopathic) had the lowest contraction frequency, but the highest amplitude, obliteration, and motility index. The remaining 6 patients (5 idiopathic and 1 diabetic) had normal GEwith contraction parameters values in between those of the DGE and RGE patients (Table 1). CONCLUSION 1) In patients with UGIMD and DGE, the antral contraction parameters as assessed by DAS are less than 1/2 the values of NGE patients; 2) RGE patients had nearly 3 times higher contraction parameters than DGE patients, specifically having longer and more coordinated forceful contractions resulting in powerful motility index and faster gastric emptying and 3) DAS data complements GES results offering important additional assessment of gastric motility characteristics and parameters that have direct application to patient care and treatment decisions. Table 1: Quantitative parameters of antral motility in patients with upper GI motility disorder

Changing Tongue Depressor Position Between Rat Incisors of Both Jaws Varies Gastric Motility

The periodontal ligament between the wall of every tooth socket &amp; the root of the tooth which it suspends allows slight tooth movement with each bite. This stimulates the ligaments' trigeminal mechanoreceptors (TMs) linked to the vagal motor n. stimulating motility of the antral region, demonstrating a periodontogastric motility reflex (Lorber, Can J Physiol Pharmacol 67:29‐35, 2000). To see whether maxillary or mandibular rat incisors might vary in performing this reflex, eight adult female rats were fasted 24‐48 h. During normal occlusion their molars occlude but not their incisors (Fig. 1A). Under pentobarbital, data were collected during three five minute periods. The first was the baseline(B) in which resting antral motility was observed. For the procedure period(P), a tongue depressor was placed vertically(V) (Fig. 1B) or horizontally(H) (Fig. 1C) between the incisors of each jaw. For (P) the mandible was closed every second for five minutes and antral motility observed. The last period was the postprocedural(PP) to note whether the antral effect extended beyond (P). Comparisons of the mean+1sd of (P) and (PP) with (B) revealed that in (V) the three values were 1.00+0.72, 1.39+0.94, 1.71+ 1.33, ANOVA P&lt;0.04. In (H) the values were 1.00+1.45, 2.43+1.08, 3.98+1.17,ANOVA P&lt;0.04. Comparing (H) and (V) by dependent t‐tests showed that (H) is greater in PP (P&lt;0.05), presumably due to delayed greater stimulation of apically located TMs than those on the sides of the dental root, whereas the V position causes anterior stimulation of only the maxillary TMs and posterior stimulation of only the mandibular TMs. This may be because the primary location of the TMs is at the root apex from which they ramify, so fewer branches are stimulated at any location about the sides of the dental root than at its tip.

Radiofrequency ablation therapy - the grave for GAVE (gastric antral vascular ectasia)?

Gastric antral vascular ectasia (GAVE) is a distinct acquired entity presenting with small ectatic vessels localized to the gastric antrum and having characteristic endoscopic features. GAVE can be observed in patients with cirrhosis with and without portal hypertension and also in other conditions such as autoimmune disorders, scleroderma, chronic renal failure, cardiac disease, following bone marrow transplantation, and in patients with a left ventricular assist device [1] [2] [3]. The pathophysiology of GAVE makes it a separate entity distinct from portal hypertensive gastropathy. Alterations in systemic blood flow, the role of local acting vasoactive substances such as nitric oxide, gastrin, and prostaglandin, and mechanical stress resulting from altered gastric antral motility are some of the proposed mechanisms.

Duodenal rather than antral motility contractile parameters correlate with symptom severity in gastroparesis patients.

Studies of symptomatic gastroparetics consistently find poor correlation with gastric emptying. We hypothesized that concomitant small bowel dysmotility may play a role in symptom causation in gastroparesis and sought to test this hypothesis by using wireless motility capsule (WMC) testing to simultaneously measure antral and duodenal area under pressure curve (AUC) in patients with delayed gastric emptying. Using a cohort from a multicenter clinical trial and a separate tertiary clinical database, we identified gastroparetics that underwent concurrent WMC testing and completed the Gastroparesis Cardinal Symptom Index, a validated questionnaire. Our study included 35 gastroparetics defined by a gastric emptying time (GET) ≥ 5 h. Antral and duodenal AUC were assessed at 1-h windows pre-GET and post-GET, respectively. We found moderate correlations between duodenal AUC and symptom severity in the combined cohort (n = 35; R = -0.42; p = 0.01; 95% CI -0.7, -0.1). Removing patients with colonic delay resulted in a stronger correlation of duodenal AUC to symptom severity (n = 21; R = -0.63; p < 0.01; 95% CI -0.81, -0.31). The multicenter trial (n = 20) and clinical practice cohorts (n = 15) had significantly different symptom severity and exclusion criteria. When analyzed separately, significant correlations between duodenal AUC and symptom severity were observed (R = -0.71; p < 0.01; 95% CI -0.9, -0.4 and R = -0.72; p < 0.01; 95% CI -0.9, -0.3, respectively). Symptom severity and antral motility showed no correlation. We found significant correlations between duodenal AUC and symptom severity in two cohorts of gastroparetics. Small bowel motility may contribute to symptom generation in gastroparetic patients and this may inform therapeutic considerations.

Administration of exogenous acylated ghrelin or rikkunshito, an endogenous ghrelin enhancer, improves the decrease in postprandial gastric motility in an acute restraint stress mouse model

BackgroundPhysical or psychological stress causes functional disorders in the upper gastrointestinal tract. This study aims to elucidate the ameliorating effect of exogenous acylated ghrelin or rikkunshito, a Kampo medicine which acts as a ghrelin enhancer, on gastric dysfunction during acute restraint stress in mice.MethodsFasted and postprandial motor function of the gastric antrum was wirelessly measured using a strain gauge force transducer and solid gastric emptying was detected in mice exposed to restraint stress. Plasma corticosterone and ghrelin levels were also measured. To clarify the role of ghrelin on gastrointestinal dysfunction in mice exposed to stress, exogenous acylated ghrelin or rikkunshito was administered, then the mice were subjected to restraint stress.Key ResultsMice exposed to restraint stress for 60 min exhibited delayed gastric emptying and increased plasma corticosterone levels. Gastric motility was decreased in mice exposed to restraint stress in both fasting and postprandial states. Restraint stress did not cause any change in plasma acylated ghrelin levels, but it significantly increased the plasma des-acyl ghrelin levels. Administration of acylated ghrelin or rikkunshito improved the restraint stress-induced delayed gastric emptying and decreased antral motility. Ameliorating effects of rikkunshito on stress-induced gastric dysfunction were abolished by simultaneous administration of a ghrelin receptor antagonist.Conclusions & InferencesPlasma acylated/des-acyl ghrelin imbalance was observed in acute restraint stress. Supplementation of exogenous acylated ghrelin or enhancement of endogenous ghrelin signaling may be useful in the treatment of decreased gastric function caused by stress.

Preventive effect of rikkunshito on gastric motor function inhibited by l-dopa in rats

We previously reported that ghrelin prevented l-dopa (LD)-induced inhibition of gastric emptying (GE) of a non-nutrient solution in rats. Parkinson's disease treatment involves the combined administration of l-dopa with the enzyme l-amino acid decarboxylase inhibitor, carbidopa (CD) to reduce peripheral formation of dopamine. We investigated the effect LD/CD given orogastrically (og) on GE of a non-nutrient or nutrient meal and whether og pretreatment with rikkunshito, a kampo medicine clinically used to treat gastroparesis, influenced LD/CD effect on GE and postprandial antral and duodenal motility in conscious rats. LD/CD (20/2mgkg−1) decreased significantly GE to 26.3±6.0% compared to 61.2±3.2% in og vehicle monitored 20-min after a non-nutrient meal and to 41.9±5.8% compared to 72.9±5.2% in og vehicle monitored 60min after a nutrient meal. Rikkunshito (0.5 or 1.0gkg−1) reduced the LD/CD (20/2mgkg−1) inhibition of GE of non-nutrient meal (36.9±7.4% and 46.6±4.8% respectively vs. 12.1±7.4% in og vehicle plus LD/CD) while having no effect alone (56.6±8.5%). The ghrelin antagonist, [d-Lys3]-GHRP-6 (1mgkg−1) injected intraperitoneally partially reversed rikkunshito preventive effect on LD/CD-inhibited GE. Rikkunshito (1.0gkg−1) blocked LD/CD (20/2mgkg−1)-induced delayed GE of a nutrient meal and the reduction of postprandial antral motility. In 6-hydroxydopamine-induced Parkinson's disease rat model, rikkunshito (1.0gkg−1, og) also prevented LD/CD-inhibited gastric emptying of a nutrient meal and enhanced fasting plasma levels of acylated ghrelin. These data indicate that oral rikkunshito alleviates the delayed GE induced by LD/CD in naïve and PD rat model in part through ghrelin-related mechanisms.

Gastric Digestion In Vivo and In Vitro: How the Structural Aspects of Food Influence the Digestion Process

Food digestion is crucial for sustaining life. Although it has been examined for more than 300 years, the basic principles are not entirely understood. Antral motility is well characterized, and current research is seeking to determine flow patterns generated by the stomach's peristaltic contractions. The rate of gastric emptying for solid and liquid meals has been determined according to variations in meal composition, energy content, and subject characteristics. The glycemic response has been measured for many carbohydrate foods and is altered by factors such as amount of processing, particle size, and starch structure. Similarly, ileal starch digestibility is altered by food and starch properties. Even though many foods have been studied according to their glycemic response, starch digestibility, and in vitro digestion kinetics, the rate-determining processes and underlying mechanisms remain to be established. The link between food properties, digestion processes, and final health outcomes must be strengthened for functional food optimization.

Invited Commentary

Invited Commentary

Impact of Gastropyloric Motor Activity on the Genesis of Reflux Esophagitis After an Esophagectomy With Gastric Tube Reconstruction

Reflux esophagitis is a significant problem in patients after an esophagectomy with gastric tube reconstruction. The pathogenesis of reflux esophagitis is not fully understood. The aim of the present study was to evaluate whether gastropyloric motility influences the pathogenesis of reflux esophagitis after an esophagectomy. Thirty esophagectomized patients were assessed by endoscopy and manometry. The patients were classified into 3 groups according to the postoperative period as follows: Group 1 (less than 12 months), group 2 (12 to 24 months), and group 3 (more than 24 months). Gastropyloric motor activity was quantified by calculating the motility index, which is equivalent to the area under the contractile waves. Reflux esophagitis was observed in 80% of group 1, 80% of group 2, and 30% of group 3. The severity of reflux esophagitis decreased with time. Contractions of the gastric body were not observed in any of the patients. The antral motility index in group 3 was significantly greater than that in groups 1 and 2. The pyloric motility index progressively increased. The severity of reflux esophagitis is significantly associated with gastropyloric motor activity. The severity of reflux esophagitis decreases with time, coupled with recovery of antropyloric motor activity. Gastropyloric motor activity plays an important role in the genesis of reflux esophagitis after an esophagectomy.

Gastric Motility Following Ingestion of a Solid Meal in a Cohort of Adult Asthmatics

Background/AimsAsthmatics have abnormal esophageal motility and increased prevalence of gastroesophageal reflux disease (GERD). The contribution of gastric motility is less studied. We studied gastric myoelectrical activity, gastric emptying (GE) and their association with GERD symptoms and vagal function in adult asthmatics.MethodsThirty mild, stable asthmatics and 30 healthy controls underwent real-time ultrasonography and 1 hour pre- and post-prandial cutaneous electrogastrography, following a test meal (480 kcal, 60% carbohydrate, 20% protein, 20% fat and 200 mL water). The percentage of normal slow waves and arrhythmias, dominant frequency and power, frequency of antral contractions, gastric emptying rate (GER) and antral motility index (MI) was calculated. Twenty-seven asthmatics underwent gastroscopy and in all subjects GERD symptoms were assessed by a validated questionnaire. Vagal function parameters were correlated with gastric motility parameters.ResultsThe asthmatics (37% male; 34.8 ± 8.4 years) and controls (50% male; 30.9 ± 7.7 years) were comparable. None had endoscopic gastric pathological changes. Twenty asthmatics described GERD symptoms. Twenty-two (73.3%) asthmatics showed a hypervagal response. Compared to controls, asthmatics had delayed GER and lower MI, lower percentage of normal gastric slow waves, more gastric dysrythmias and failed to increase the post-prandial dominant power. There was no correlation of GE and cutaneous electrogastrography parameters with presence of GERD symptoms or with vagal function.ConclusionsAsthmatics showed abnormal gastric myoelectrical activity, delayed GE and antral hypomotility in response to a solid meal compared to controls. There was no association with vagal function or GERD symptom status.

Gastric emptying and antral motility parameters in children with functional dyspepsia: Association with symptom severity

Functional dyspepsia (FD) is an important gastrointestinal problem with obscure etiology. Abnormal gastric motility is suggested as a possible pathophysiological mechanism for symptoms. The main objective of this study was to assess gastric motility in Sri Lankan children with FD. Forty-one children (19 [46.3%] males, age 4-14 years, mean 7.5 years, SD 2.6 years) referred to the Gastroenterology Research Laboratory, Faculty of Medicine, University of Kelaniya, from January 2007 to December 2011, were screened. Those fulfilling Rome III criteria for FD were recruited. None had clinical or laboratory evidence of organic disorders. Twenty healthy children were recruited as controls (eight [40%] males, age 4-14 years, mean 8.4 years, SD 3.0 years). Liquid gastric emptying rate (GE) and antral motility parameters were assessed using an ultrasound-based method. Average GE (45.6% vs 66.2% in controls), amplitude of antral contractions (58.2% vs 89.0%) and antral motility index (5.1 vs 8.3) were lower and fasting antral area (1.5 cm(2) vs 0.6 cm(2)) was higher in patients with FD (P < 0.01). Frequency of antral contractions (8.8 vs 9.3) did not show a significant difference (P = 0.07). Scores obtained for severity of abdominal pain negatively correlated with GE (r = -0.35, P = 0.025). Children with FD, exposed to stressful events had higher fasting antral area (1.9 cm(2)) than those not exposed to stress (1.0 cm(2)) (P = 0.02). GE and antral motility parameters were significantly impaired in children with FD compared with controls. GE negatively correlated with severity of symptoms. This study points to disturbances in gastric motility as an etiological factor for FD.

Tu2086 The Endocannabinoid System (ECS) and the Hypothalamic-Pituitary-Adrenal (HPA) Axis in Adults With Cyclic Vomiting Syndrome (CVS)

Background: The most commonly used drug for Parkinson disease (PD) therapy, levodopa (L-dopa) induces delayed gastric emptying (GE) in PD patients and healthy controls. We previously reported that ghrelin could prevent L-dopa-inhibited GE in rats. Rikkunshito is a kampo medicine that increases ghrelin in humans and mice and used clinically in Japan to treat functional and chemotherapy-induced dyspepsia, and post-operative gastric ileus. Aim: To investigate whether rikkunshito mimics ghrelin effect to improve gastric motility in L-dopa-treated rats. Methods: In overnight fasted rats, rikkunshito (Gastroenterology 2008, 143:2004), or vehicle (distilled water) was administered by orogastic gavage (og) 170 min before L-dopa/carbidopa (LD/CD, og), 10 min later followed by a meal (methylcellulose/ phenol red or 40% powder meal in water with 50% glass bead, og), and GE was assessed 20 min (non-nutrient solution) or 60 min (nutrient meal) thereafter. The ghrelin antagonist, D-[Lys3]-GHRP-6 was injected IP at the same time as rikkunshito and GE was determined 20 min after og LD/CD or vehicle. Strain gauge transducer was implanted in the rat antrum. After 6 days, overnight food restricted rats were treated with rikkunshito or vehicle and 170 min later with L-dopa or vehicle (IP) and then 10 min later, the powder meal solution was gavaged and antral motility was recorded for 60 min. Food intake was monitored after rikkunshito and LD/CD gavage in overnight fasted rats. Results: LD/CD (15/1.5, 20/2 and 50/5 mg/kg, og) dose-dependently inhibited GE of nutrient meal (58.1±4.1%, 41.9±5.8%*, 28.9±5.6%* vs. vehicle 72.9±5.2%, respectively, *:p,0.05). In vehicle pretreated rats, LD/ CD (20/2 mg/kg, og) decreased GE of a non-nutrient meal compared to vehicles (12.1±7.4% vs. 49.3±7.0%, p,0.05). Rikkunshito (0.5 or 1.0 g/kg, og) prevented dose-dependently the LD/CD inhibitory effect on GE (36.9±7.4% and 46.6±4.8% respectively, p,0.05 vs. vehicle plus LD/CD) while having no effect alone (56.6±8.5%). Likewise, rikkunshito (1.0 g/kg) blocked LD/CD reduced GE of the nutrient meal (61.4±4.1% vs. 43.0±5.0%, p ,0.05) compared to vehicles (71.5±5.0%). L-dopa (15 mg/kg)-induced reduction of antral motility (motility index 78.3±3.4 vs. vehicle 103.3±6.7, p,0.05) was blocked by rikkunshito (1.0 g/kg; motility index 102.0±5.4). D-[Lys3]-GHRP-6 (1 mg/kg) partially reversed rikkunshito effect on LD/CD-inhibited GE. There was no significant difference in cumulative food intake response to a fast at 1, 2, 4 and 24 h after og rikkunshito (1.0 g/kg) plus LD/CD (20/2 mg/ kg). Conclusions: Rikkunshito exerts a gastroprokinetic effect under conditions of levodopainhibited gastric motor function that may be in part mediated by ghrelin. Rikkunshito may have therapeutic application to improve gastric transit in levodopa treated-PD patients. Supported by Tsumura & Co. and NIDDK 41303 (animal core)

Tu2085 Rikkunshito Prevents Levodopa-Inhibited Gastric Motility in Fasted Rats

Background: The most commonly used drug for Parkinson disease (PD) therapy, levodopa (L-dopa) induces delayed gastric emptying (GE) in PD patients and healthy controls. We previously reported that ghrelin could prevent L-dopa-inhibited GE in rats. Rikkunshito is a kampo medicine that increases ghrelin in humans and mice and used clinically in Japan to treat functional and chemotherapy-induced dyspepsia, and post-operative gastric ileus. Aim: To investigate whether rikkunshito mimics ghrelin effect to improve gastric motility in L-dopa-treated rats. Methods: In overnight fasted rats, rikkunshito (Gastroenterology 2008, 143:2004), or vehicle (distilled water) was administered by orogastic gavage (og) 170 min before L-dopa/carbidopa (LD/CD, og), 10 min later followed by a meal (methylcellulose/ phenol red or 40% powder meal in water with 50% glass bead, og), and GE was assessed 20 min (non-nutrient solution) or 60 min (nutrient meal) thereafter. The ghrelin antagonist, D-[Lys3]-GHRP-6 was injected IP at the same time as rikkunshito and GE was determined 20 min after og LD/CD or vehicle. Strain gauge transducer was implanted in the rat antrum. After 6 days, overnight food restricted rats were treated with rikkunshito or vehicle and 170 min later with L-dopa or vehicle (IP) and then 10 min later, the powder meal solution was gavaged and antral motility was recorded for 60 min. Food intake was monitored after rikkunshito and LD/CD gavage in overnight fasted rats. Results: LD/CD (15/1.5, 20/2 and 50/5 mg/kg, og) dose-dependently inhibited GE of nutrient meal (58.1±4.1%, 41.9±5.8%*, 28.9±5.6%* vs. vehicle 72.9±5.2%, respectively, *:p,0.05). In vehicle pretreated rats, LD/ CD (20/2 mg/kg, og) decreased GE of a non-nutrient meal compared to vehicles (12.1±7.4% vs. 49.3±7.0%, p,0.05). Rikkunshito (0.5 or 1.0 g/kg, og) prevented dose-dependently the LD/CD inhibitory effect on GE (36.9±7.4% and 46.6±4.8% respectively, p,0.05 vs. vehicle plus LD/CD) while having no effect alone (56.6±8.5%). Likewise, rikkunshito (1.0 g/kg) blocked LD/CD reduced GE of the nutrient meal (61.4±4.1% vs. 43.0±5.0%, p ,0.05) compared to vehicles (71.5±5.0%). L-dopa (15 mg/kg)-induced reduction of antral motility (motility index 78.3±3.4 vs. vehicle 103.3±6.7, p,0.05) was blocked by rikkunshito (1.0 g/kg; motility index 102.0±5.4). D-[Lys3]-GHRP-6 (1 mg/kg) partially reversed rikkunshito effect on LD/CD-inhibited GE. There was no significant difference in cumulative food intake response to a fast at 1, 2, 4 and 24 h after og rikkunshito (1.0 g/kg) plus LD/CD (20/2 mg/ kg). Conclusions: Rikkunshito exerts a gastroprokinetic effect under conditions of levodopainhibited gastric motor function that may be in part mediated by ghrelin. Rikkunshito may have therapeutic application to improve gastric transit in levodopa treated-PD patients. Supported by Tsumura & Co. and NIDDK 41303 (animal core)

Role of duodenal mucosal nerve endings in the acid‐induced duodenogastric sensorimotor reflex: Effect of benzocaine in healthy humans

Duodenal acid exposure induces a duodenogastric reflex resulting in gastric relaxation, inhibition of antral motility, and sensitization of the proximal stomach to distension. Duodenal hypersensitivity to acid has been identified as a potential pathogenic mechanism in functional dyspepsia. The nature and localization of the duodenal acid-sensitive receptors are still elusive. We hypothesize that acid directly activates superficial afferent nerve endings in the duodenal mucosa, triggering the duodenogastric reflex. In a double-blind, randomized, crossover study in 13 healthy volunteers, benzocaine, a local anesthetic, vs saline was perfused in the duodenum 15 min before duodenal acid perfusion. Gastric responses were monitored by a barostat. Stepwise isobaric gastric distensions were performed before and during acid perfusion. Symptoms were evaluated by visual analogue scales for six dyspeptic symptoms and an overall perception score. Benzocaine perfusion caused a relaxation of the stomach prior to duodenal acidification, indicating the existence of an excitatory duodenogastric tone. Pretreatment of the duodenum with benzocaine reduced the acid-induced gastric relaxation by 50% and abolished the inhibition of phasic motility of the proximal stomach. Finally, sensitization to distension was more pronounced in the benzocaine condition because of higher proximal gastric volumes. These findings support a model in which different neuronal subpopulations are responsible for the motor and sensory limb of the acid-sensitive duodenogastric reflex, making benzocaine an unsuitable drug to treat duodenal hypersensitivity to acid. These data provide more insight in the contribution of duodenal neuronal input to gastric physiology in the fasting state.