Changes in the position and angulation of incisura during contractions of the isolated cat stomach

Abstract Contractions change the configuration of the lesser curvature of the stomach while they indent the greater curvature. We studied these lesser curvature changes by measuring the position and angle of the gastric incisura on still frames captured from videotapes of isolated cat stomachs suspended in physiologic solution. In response to filling with 100 mL Krebs' solution stomachs generated a tonic contraction of the fundus/body segment and gave rise to a peristaltic contraction that spread from the body and through the antrum to the pylorus. In preparations where we left the duodenal cannula open we found that the incisura moves toward the gastro-oesophageal (GO) junction and the angle of the incisura widens as the contraction passes through the stomach and empties its contents. Furthermore, the angle of the incisura is most acute when the full stomach starts contracting in its fundic segment and again when the contraction involves the gastric sinus (the wedge-shaped segment adjacent to the incisura which forms the transition between the body and the antrum of the stomach). In preparations where the duodenal cannula was kept closed, the angle of the incisura becomes most acute when the contraction involves the gastric body and when the luminal pressure peaks. We conclude that changes in the position and angulation of the incisura are part of the mechanical response of the stomach to filling and emptying; unlike the peristaltic contraction along the greater curvature the net movement of the incisura goes in the orad direction. Movements of the incisura profoundly affect the configuration of the stomach and hence the distribution of luminal contents between various gastric segments. The gastric sling muscles are responsible for the formation of the gastric incisura but their role in any movements of the incisura remains to be defined.     

Gastric electrical stimulation at proximal stomach induces gastric relaxation in dogs

Gastric electrical stimulation (GES) improves symptoms in patients with gastroparesis. However, the underlying mechanisms remain unclear. To determine if GES at proximal and distal stomach could affect the biomechanical properties of the stomach, thus contributing to the beneficial effect of GES. Four pairs of electrodes were implanted along the greater curvature of the stomach in seven dogs. Gastric tone and compliance was assessed with a barostat. Measurements were obtained randomly during control and proximal and distal stimulation (4 mA, 375 ms and 6/18 cpm). Data as mean or median (25-75th percentiles). Gastric compliance was not affected by proximal and distal GES. Gastric tone was significantly reduced during proximal GES: 82.0 (66.8, 89.1) mL vs control 49.7 (39.6,75.9) mL at 6 cpm (P = 0.016), and 90.6 (54.5, 117.9) mL vs control 62.8 (39.6, 75.9) mL at 18 cpm (P = 0.031). Tone was not affected by distal GES at 6 cpm: 95.8 (46.3, 106.7) mL vs control 75.2 (49.7, 86.1) mL (P = 0.47) and at 18 cpm: 80.4 (38.1, 170.3) mL vs control 62.8 (44.6, 156.3) mL (P = 0.44). Proximal GES induces gastric relaxation. This effect, if seen also in humans, may explain, in part, the symptomatic improvement associated with GES therapy in patients with gastroparesis.     

Two‐channel gastric pacing in patients with diabetic gastroparesis

Background Our primary goals were to investigate the effects of two‐channel gastric pacing on gastric myoelectrical activity, and energy consumption with the secondary intent to monitor gastric emptying and symptoms in patients with severe diabetic gastroparesis. Methods Four pairs of temporary pacing wires were inserted on the serosa of the stomach at the time of laparotomy to place the Enterra? System in 19 patients with severe gastroparesis not responding to standard medical therapies. Two of the pairs were for electrical stimulation and the other two for recording. Five days after surgery the optimal pacing parameters for the entrainment of gastric slow waves in each patient were identified by serosal recordings. Two‐channel gastric pacing was then initiated for 6 weeks using a newly developed external multi‐channel pulse generator. Electrogastrogram (EGG), Total Symptom Score (TSS), and a 4‐h gastric emptying test were assessed at baseline and after 6 weeks of active gastric pacing. Enterra? device was turned OFF during the duration of this study. Key Results Two‐channel gastric pacing at 1.1 times the intrinsic frequency entrained gastric slow waves and normalized gastric dysrhythmia. After 6 weeks of gastric pacing, tachygastria was decreased from 15 ± 3 to 5 ± 1% in the fasting state and from 10 ± 2 to 5 ± 1% postprandially (P < 0.05), mean TSS was reduced from 21.3 ± 1.1 to 7.0 ± 1.5 (P < 0.05) and mean 4‐h gastric retention improved from 42 to 28% (P = 0.05). Conclusions & Inferences Two‐channel gastric pacing is a novel treatment approach which is able to normalize and enhance gastric slow wave activity as well as accelerate gastric emptying in patients with diabetic gastroparesis with a goal safety profile.     

Reproducibility of gastric tone, compliance and gastric accommodation assessed with barostat in conscious dogs

The reproducibility of barostat measurements was unclear. In this study, the intraday and interday reproducibility of barostat measurements of gastric tone, compliance and gastric accommodation were assessed in a canine model. A series of experiments were performed using a barostat system in 11 surgically prepared healthy dogs: (i) interday gastric tone and compliance: three sessions on three separate days; (ii) intraday gastric tone and compliance: two sessions on the same day separated by a 30-min interval; (iii) interday gastric accommodation: two sessions on two separate days, with each including a 30-min baseline and a 60-min postprandial period. The results were (i) interday gastric tone (81.2 +/- 7.5 mL vs 89.2 +/- 8.1 mL vs 86.2 +/- 13.6 mL, n = 11) and compliance (n = 8) were comparable; (ii) intraday gastric tone (87.9 +/- 17.2 mL vs 77.0 +/-14.8 mL, n = 8) and compliance (n = 8) was also similar, but with considerable individual variance; (iii) interday gastric accommodation was 320.8 +/-45.1 mL vs 287.9 +/- 31.2 mL, no significant difference (n = 8). Inter- and intraday gastric tone and compliance and interday gastric accommodation were relatively reproducible in most animals when tested under well-controlled conditions. However, considerable variations may occur in fasting gastric tone and compliance measurements in certain individuals and cautions should be given when interpreting related results.     

Effect of mianserin on gastric sensorimotor function and gastric emptying: a randomized,placebo‐controlled,double‐blind,crossover study in healthy volunteers

Background Antidepressants such as mianserin can improve symptoms in some functional dyspeptic patients but their mechanism of action remains unclear. We aimed to assess the effects of mianserin on gastric sensorimotor function in man. Methods In this randomized, placebo‐controlled, double‐blind, crossover study 12 healthy subjects (six men) underwent a gastric barostat study and a gastric emptying breath test after 7 days pretreatment with placebo or mianserin (20 mg; p.o.). Graded isobaric and isovolumetric distentions were performed to determine gastric compliance and sensitivity. Subsequently, intrabag pressure was held constant and the volume increase after administration of a liquid meal (200 mL; 300 kcal) was studied. Breath was sampled before and after ingestion of a test meal and half‐emptying times for solids and liquids were determined from the breath samples. Mianserin was compared to placebo using t‐tests and mixed model analysis (mean ± SD). Key Results Mianserin did not affect pressures or volumes needed to induce first perception or discomfort. During isovolumetric distensions compliance was decreased after mianserin treatment (1.8 ± 0.4 vs 2.0 ± 0.3 mmHg 100 mL^?1; P < 0.05). Premeal volumes were comparable in both treatment arms (221 ± 99 vs 220 ± 88 mL), but meal‐induced relaxation during the first 30 min was significantly inhibited after mianserin treatment (F_6,40 = 2.58, P < 0.05). Mianserin did not affect either solid or liquid gastric emptying. Conclusions & Inferences Mianserin does not alter gastric emptying rate or sensitivity to gastric distension, but inhibits gastric accommodation to a meal in its early phase. These observations provide no explanation for the effects of mianserin in functional dyspeptic patients.     

Development of gastric slow waves and effects of feeding in pre-term and full-term infants

The aims of this study were to investigate the difference in developmental process of gastric slow waves and the effects of feeding in pre-term and full-term infants. Twenty-six pre-term and 31 full-term infants were enrolled in the study. Gastric myoelectrical activity was recorded using electrogastrography (EGG) from birth to month 6. An increase in the % of 2-4 cpm slow waves was noted in both pre-term (P < 0.01) and full-term infants (P < 0.04) from birth to month 4. The pre-term infants showed a reduced dominant EGG power at certain points of the study. (3) Breast or formula feeding resulted in no difference in the EGG in the full-term infants and showed a difference in the postprandial dominant power of the EGG in the pre-term infants only at month 2 after birth (P < 0.05) but not at other times. The gastric slow wave in pre-term infants is of a significantly reduced amplitude but similar rhythmicity. The method of feeding has no effects on the EGG in full-term infants and minimal effects (may be of non-clinical significance) on the EGG in pre-term infants as the difference was noted only at one time point during the 6-month follow-up study.     

The relationship between gastric pH and the emptying of solid, semisolid and liquid meals

The effect of three different meal constituents, solid, semisolid and liquid, on gastric pH, recorded in the proximal and distal stomach, was evaluated in a prospective study of 20 normal volunteers. The solid and liquid were ingested together as one meal and the semisolid as another. Simultaneous recordings of the rate of gastric emptying of the isotopically labelled meal constituents and the gastric pH were made. The rate of gastric emptying was more rapid for the liquid and semisolid constituents (t_1/2= 35.6, range 9.8–103.3 min and 47.4, range 33.5–120 min, respectively) than for the solid meal constituent (t_1/2= 72.0, range 45.0–103.8 min), P < 0.01. Both the combined meal of solid and liquid and the semisolid meal produced a higher pH response in the proximal stomach than in the distal stomach (5.2, range 2.4–6.1 vs 2.9, range 0.8–5.3 and 5.9, range 4.3–6.6 vs 4.3, range 1.1–5.9), P < 0.01. There were significant correlations between the rate of gastric emptying of all three meal constituents and the decline phase in the gastric pH recorded at both the proximal and distal probes, P < 0.01 (Pearson's correlation). The strongest correlations were found between the rate of gastric emptying and the gastric pH recorded in the proximal stomach. The decline phase of gastric pH followed the emptying of semisolid more closely than the emptying of either solid or liquid.     

Vagal activation by sham feeding improves gastric motility in functional dyspepsia

Abstract  Antral hypomotility and impaired gastric accommodation in patients with functional dyspepsia have been ascribed to vagal dysfunction. We investigated whether vagal stimulation by sham feeding would improve meal-induced gastric motor function in these patients. Fourteen healthy volunteers and 14 functional dyspepsia patients underwent a drink test twice, once with and once without simultaneous sham feeding. After ingesting 500 mL clear meat soup (20 kcal, 37 °C) in 4 min, sham feeding was performed for 10 min by chewing a sugar-containing chewing gum while spitting out saliva. Using two- and three-dimensional ultrasound, antral motility index (contraction amplitude × frequency) and intragastric volumes were estimated. Without sham feeding, functional dyspepsia patients had lower motility index than healthy volunteers (area under curve 8.0 ± 1.2 vs 4.4 ± 1.0 min⁻¹, P  =   0.04). In functional dyspepsia patients, but not in healthy volunteers, motility index increased and intragastric volume tended to increase by sham feeding ( P  = 0.04 and P  = 0.06 respectively). The change in motility index was negatively correlated to the change in pain score ( r  = −0.59, P  = 0.007). In functional dyspepsia patients, vagal stimulation by sham feeding improves antral motility in response to a soup meal. The result supports the view that impaired vagal stimulation is implicated in the pathogenesis of gastric motility disturbances in functional dyspepsia.     

Altered neuroendocrine response and gastric dysmotility in the Flinders Sensitive Line rat

In the search for animal models that can replicate some features of functional dyspepsia (FD) patients, we turned our interest to the Flinders Sensitive Line (FSL) rat. Gastric motility disturbances prevalent in FD patients as well as urine corticosterone and plasma prolactin were measured following buspirone challenge. Flinders Resistant Line (FRL) rat was used as control. The results show that the FSL rats have a disturbed gastric motility, reflected as both an increased gastric accommodation rate and gastric volume during gastric distension as well as a delayed gastric emptying, the latter possibly as a consequence of the former. Lipid administration resulted in a significant increase in maximal gastric volume only in the FRL rats. Both the corticosterone response to buspirone and the 24-h urinary output of corticosterone were normal in FSL rats. Similar to FD patients, the FSL rat showed supersensitivity to buspirone in the increase in prolactin release. Although FSL rats show some features similar to a subset of FD patients, the increased gastric accommodation contrasts to the reduced accommodation often seen in FD patients. Further studies are warranted to determine the relevance of this rat strain as a model for FD.     

Influence of gastric acid on gastric emptying and gastric distension-induced pain response in rats - effects of famotidine and mosapride

Background Gastroduodenal acidification has been reported to aggravate upper abdominal discomfort and pain that are symptoms suffered by functional dyspepsia (FD) patients. Delayed gastric emptying and hypersensitivity to gastric distension (GD) contribute importantly to the pathophysiology of FD. Methods In the present study, we determined the influence of pentagastrin‐stimulated endogenous gastric acid on gastric emptying and GD‐induced pain responses using rat model systems. Moreover, we evaluated the effects of famotidine and mosapride on changes in gastric emptying and the GD‐induced pain response to gastric acid hypersecretion. Gastric emptying was measured by excretion of glass beads that had been intragastrically administered with a liquid nutrient, and gastric pain response was evaluated by observing whether a GD‐induced increase in mean blood pressure occurred. Key Results Pentagastrin (2 mg kg^?1, s.c.) which markedly and continuously stimulated gastric acid secretion, significantly delayed and enhanced respectively, gastric emptying and pain compared with saline‐injected groups. Oral famotidine (0.1–3 mg kg^?1) and mosapride (0.3–3 mg kg^?1) administration in a dose‐dependent manner accelerated the delay of gastric emptying. Furthermore, famotidine (0.3–3 mg kg^?1) significantly alleviated the aggravation of the GD‐induced pain response, but mosapride (10 mg kg^?1) did not. Conclusions & Inferences We established rat models to evaluate the effect of gastric acid hypersecretion on gastric emptying and the GD‐induced pain response. In these models, acid hypersecretion delayed gastric emptying and aggravated the pain response. Furthermore, we showed that famotidine ameliorated both delayed gastric emptying and gastric hypersensitivity, whereas mosapride only improved delayed gastric emptying.     

Postprandial gastric antral contractions in patients with gastro-oesophageal reflux disease: a scintigraphic study

Abstract  Disturbed gastric contractility has been found in manometric studies in patients with gastro-oesophageal reflux disease (GORD), but the pathophysiological role of this abnormality is unclear. We aimed at assessing postprandial gastric antral contractions and its relationships with gastric emptying and gastro-oesophageal reflux in GORD patients. Fasted GORD patients ( n  = 13) and healthy volunteers ( n  = 13) ingested a liquid meal labelled with 72 MBq of ^99mTechnetium-phytate. Gastric images were acquired every 10 min for 2 h, for measuring gastric emptying half time. Dynamic antral scintigraphy (one frame per second), performed for 4 min at 30-min intervals, allowed estimation of both mean dominant frequency and amplitude of antral contractions. In GORD patients ( n  = 10), acidic reflux episodes occurring 2 h after the ingestion of the same test meal were determined by ambulatory 24-h oesophageal pH monitoring. Gastric emptying was similar in GORD patients and controls (median; range: 82 min; 58–126 vs 80 min; 44–122 min; P  = 0.38). Frequency of antral contractions was also similar in both groups (3.1 cpm; 2.8–3.6 vs 3.2 cpm; 2.4–3.8 cpm; P  = 0.15). In GORD patients, amplitude of antral contractions was significantly higher than in controls (32.7%; 17–44% vs 23.3%; 16–43%; P  = 0.01), and correlated positively with gastric emptying time ( R _s = 0.58; P  = 0.03) and inversely with the number of reflux episodes ( R _s = −0.68; P  = 0.02). Increased amplitude of postprandial gastric antral contractions in GORD may comprise a compensatory mechanism against delayed gastric emptying and a defensive factor against acidic gastro-oesophageal reflux.     

Influence of tegaserod on proximal gastric tone and on the perception of gastric distention in functional dyspepsia

Background Abnormalities in gastric sensorimotor function (hypersensitivity to distention and impaired meal accommodation) have been implicated in the pathophysiology of functional dyspepsia (FD). To study the effect of the 5‐HT₄ agonist tegaserod on sensitivity to gastric distention and gastric accommodation in FD. Methods Thirty FD patients (7 males, mean age 42 ± 2 years) underwent a gastric barostat study on two separate occasions, 2 weeks apart, after 5 days of pretreatment with placebo or tegaserod 6 mg b.i.d. in a double‐blind randomized order. After introduction of the barostat bag, graded isobaric distentions (2 mmHg increments/2 min) were performed to determine gastric compliance and sensitivity to distention. Subsequently, the pressure level was set at intra‐abdominal pressure [minimal distending pressure (MDP)] + 2 mmHg for 90 min, with administration of a liquid meal (200 mL; 300 kcal) after 30 min. Key Results Tegaserod had no influence on MDP (7.9 ± 0.4 vs 7.4 ± 0.4 mmHg) or fasting gastric compliance (44 ± 10 vs 61 ± 6 mL mmHg^?1) and on fasting thresholds for first perception (3.6 ± 0.4 vs 4.2 ± 0.2 mmHg above MDP) or discomfort (9.9 ± 0.7 vs 10.5 ± 0.5 mmHg above MDP). Tegaserod did not alter intra‐balloon volumes before and after the meal [respectively 146 ± 14 vs 120 ± 11 and 297 ± 28 vs 283 ± 29 mL, not significant (NS)], or the amplitude of the meal‐induced gastric relaxation (151 ± 23 vs 162 ± 23 mL, NS). In the subgroup with normal gastric emptying (n = 22), tegaserod significantly enhanced meal‐induced accommodation (126 ± 23 vs 175 ± 29 mL, anova P < 0.001). Conclusions & Inferences Tegaserod does not alter gastric sensorimotor function in FD patients as a group. In the subgroup with normal gastric emptying, tegaserod 6 mg b.i.d enhanced gastric accommodation.     

Cyclooxygenase-2 inhibition increases gastric tone and delays gastric emptying in rats.

We evaluated the effects of cyclooxygenase-2 (COX-2) selective inhibitors, COX-1 selective inhibitor, or COX non-selective inhibitor on gastric emptying and intestinal transit of liquids, and evaluated the effect of a COX-2 selective inhibitor on gastric tonus (GT). Male Wistar rats were treated per os with saline (control), rofecoxib, celecoxib, ketorolac, rofecoxib + ketorolac, celecoxib + ketorolac, or indomethacin. After 1 h, rats were gavage-fed (1.5 mL) with the test meal (5% glucose solution with 0.05 g mL(-1) phenol red) and killed 10, 20 or 30 min later. Gastric, proximal, medial or distal small intestine dye recovery (GDR and IDR, respectively) were measured by spectrophotometry. The animals of the other group were treated with i.v. valdecoxib or saline, and GT was continuously observed for 120 min using a pletismomether system. Compared with the control group, treatment with COX-2 inhibitors, alone or with ketocolac, as well as with indomethacin increased GDR (P < 0.05) at 10-, 20- or 30-min postprandial intervals. Ketorolac alone did not change the GDR, but increased the proximal IDR (P < 0.05) at 10 min, and decreased medial IDR (P < 0.05) at 10 and 20 min. Valdecoxib increased (P < 0.01) GT 60, 80 and 100 min after administration. In conclusion, COX-2 inhibition delayed the gastric emptying of liquids and increased GT in rats.     

Effect of high-frequency gastric electrical stimulation on gastric myoelectric activity in gastroparetic patients

The aim of this study was to investigate the effect of gastric electrical stimulation (GES) on gastric myoelectric activity (GMA) and to identify possible mechanisms that could help explain how high-frequency GES is effective in treating nausea and vomiting associated with gastroparesis. Fifteen gastroparetic patients who received high-frequency GES were enrolled. Two pairs of temporary pacing wires were implanted on the serosa of the stomach along the greater curvature during surgery for placement of the permanent stimulation device. Two-channel serosal recordings of GMA before and during GES were measured. A gastric emptying test and severity of nausea and vomiting were assessed at baseline and at 3 months of GES. Power spectral and cross correlation analyses revealed that impaired propagation of slow waves (50%), tachygastria (30%) and abnormal myoelectric responses to a meal (50%) were the main abnormalities observed at baseline. GES with a high frequency significantly enhanced the slow wave amplitude and propagation velocity, and resulted in a significant improvement in nausea and vomiting but did not entrain the gastric slow wave or improve gastric emptying after 3 months of GES.     

Proximal stomach function in obesity with normal or abnormal oesophageal acid exposure

There is an increased prevalence of gastro-oesophageal reflux and symptoms in obese patients. Information about the proximal stomach in obese patients with reflux is lacking. Gastric volume and compliance are similar between obese and lean subjects. To study the proximal stomach function and perception in obese patients with normal or abnormal oesophageal acid exposure, thirty-one obese patients, with normal or abnormal oesophageal acid exposure, underwent medical evaluation of oesophageal and gastrointestinal symptoms by a questionnaire and measurement of proximal stomach function and perception by an electronic barostat and a standardized questionnaire. Nineteen obese patients had abnormal oesophageal acid exposure. The percentage of total time with pH <4 is significantly related to the presence of hiatal hernia, the oesophageal intensity-frequency symptom score and gender, i.e. higher percentage in men. The perception cumulative score was significantly different between patients with normal and abnormal oesophageal acid exposure after adjusting for covariates (gender, body mass index, age, minimal distending pressure, gastric tone and gastric compliance). Gastric tone and compliance were significantly related to the perception cumulative score. In conclusion, patients with abnormal oesophageal acid exposure have increased gastric perception. A significant relation among gastric tone, gastric compliance and upper gastrointestinal sensations was shown.     

Inhibitory effects of sildenafil on gastric motility and gastric slow waves in dogs

The aim of this study was to investigate the effects of sildenafil on gastric motility and gastric slow waves in dogs. The study was performed in healthy dogs and composed of three experiments. The first experiment was designed to study the effects of sildenafil on gastric emptying and gastric slow waves. The second experiment was used to investigate the effects of sildenafil on gastric tone. The third experiment was used to study the effects of sildenafil on postprandial antral contractions. (i) Sildenafil did not alter gastric emptying of liquid. (ii) Sildenafil had no effects on dominant frequency and percentage of normal gastric slow waves. The dominant power of gastric slow waves was, however, significantly reduced with sildenafil (P < 0.02). (iii) Fasting gastric volume with sildenafil was significantly higher than that at baseline (P < 0.0005) or in the control session (P < 0.002). However, the postprandial gastric volume was not altered with sildenafil. (iv) Sildenafil inhibited gastric antral motility. The contraction index was 338.5 +/- 39.99 at baseline and 122.5 +/- 20.3 after the injection of sildenafil (P = 0.003). Sildenafil inhibits fundic tone and antral motility but does not seem to delay gastric emptying of liquid in dogs. The amplitude but not the frequency or regularity of the gastric slow wave is inhibited by sildenafil.     

A dose-ranging, placebo-controlled, pilot trial of Acotiamide in patients with functional dyspepsia

Abstract  Impaired gastric accommodation, hypersensitivity to distension and delayed gastric emptying are major pathophysiological mechanisms in functional dyspepsia (FD). Acotiamide (Z-338) was well-tolerated in healthy volunteers. To determine the effect of three doses of Acotiamide on major pathophysiological mechanisms, symptoms, quality of life (QOL) and safety in functional dyspeptics. A phase IIa, randomized, double-blind, placebo-controlled study (14, 21 and 28 days, respectively, for run-in, study drug administration and follow-up). Gastric accommodation, sensitivity to distension and gastric emptying were assessed by barostat and ¹³C breath test, symptoms by daily diary cards and QOL by SF-36. A total of 71 patients were enrolled (62 evaluable). There was no effect on gastric emptying and sensitivity to distension. 300 mg was better than placebo for meal accommodation ( P  = 0.024). 100 mg was better than placebo at week 2 for upper abdominal bloating ( P  = 0.001) and overall symptom score ( P  = 0.022), and at week 3 for bloating ( P  = 0.008) and heartburn ( P  = 0.041). 100 mg was also better than placebo for QOL (physical function) ( P  = 0.003). Acotiamide was safe and well-tolerated in patients with FD. The involved mechanism could at least in part depend on an effect on meal-induced accommodation. 100 mg Acotiamide exhibited the potential to improve FD symptoms and QOL. Further studies are indicated.     

Reproducibility and symptomatic predictors of a slow nutrient drinking test in health and in functional dyspepsia

Abstract  Impaired accommodation to a meal has been recognized as a pathophysiological mechanism in functional dyspepsia (FD). Based on observations in tertiary care patients, the drinking test has been proposed as a non-invasive tool to estimate accommodation. Our aim was to assess the reproducibility of the drinking test and its correlation with demographic, symptomatic and pathophysiological parameters in secondary care FD patients and healthy controls. Thirty-four healthy controls and 78 FD patients completed a drinking test (3 respectively 2 times), a gastric emptying study and an FD symptom questionnaire. Factors influencing maximal volume and gastric emptying were determined, and the reproducibility of the drinking test was investigated. The maximal satiety was reached at a lower volume in patients (489 ± 276 and 503 ± 248 mL for first and second test respectively vs 937 ± 428 and 1048 ± 421 mL, P  < 0.0001). The ingested amount depended on age, sex and baseline FD symptom score. Patients' sex, final satiety score, total score for stomach complaints at screening and total symptom score before test accounted for the total symptom score after the test. The slow nutrient drinking test confirms its possible role as an attractive non-invasive and reproducible tool for the diagnosis of impaired accommodation and for the assessment of treatment responsiveness.     

Gastric distension alters frequency and regularity but not amplitude of the gastric slow wave

Abstract The aim of this study was to assess effects of gastric distension on gastric slow waves using internal and cutaneous electrodes and the correlation between these two measurements. The study was performed in five dogs implanted with one pair of serosal electrodes and a gastric cannula. Gastric slow waves were recorded using both cutaneous and internal electrodes in several sessions with different volumes (150-600 mL) of gastric distension with a barostat balloon. Bethanechol was injected in one of sessions. The results revealed that (i) Gastric distension reduced slow wave frequency in a volume-dependent manner and induced bradyarrhythmia at a volume of 600 mL, but had no effects on the amplitude of gastric slow waves. (ii) The cutaneous electrogastrogram (EGG) was significantly correlated with the internal recording in slow wave frequency (r = 0.88, P < 0.001) and regularity (r = 0.44, P = 0.035). (iii) The EGG amplitude was not increased when the stomach was distended but increased after bethanechol. Gastric distension volume dependently reduces slow wave frequency and induces gastric dysrhythmia at a large volume. The frequency and rhythmicity of the slow wave measured from the EGG are significantly correlated with those recorded from the internal electrodes. Relative increase in EGG amplitude reflects contractility rather than the distension of the stomach.