Gastric Emptying Of Liquid Meal Research Articles

Evaluation of Gastric Emptying by Transabdominal Ultrasound after Oral Administration of Semisolid Cellulose-Based Gastric Ultrasound Contrast Agents

Many previous studies have found that transabdominal ultrasound may allow precise measurement of gastric emptying of liquid meals. However, the clinical use of this technique has been hampered by the limitation that transabdominal ultrasound might not accurately measure gastric emptying of solid meals. It is more important to measure gastric emptying of solids instead of liquids, as gastric emptying of solids is more often delayed than gastric emptying of liquids in gastric motility disorders. Recently, transabdominal ultrasound after oral administration of a cellulose-based gastric contrast agents (TUS-OSCA) has been suggested to be effective in initial screening of gastric lesions. The aim of this study was to explore the accuracy of TUS-OSCA in the evaluation of gastric emptying of a semisolid meal. Twenty healthy young patients (10 males and 10 females aged 25.5 ± 2.5 y) were studied. Concurrent measurements of gastric emptying by scintigraphy and TUS-OSCA were performed after ingestion of 350 mL semisolid ultrasound agent labeled with 20 MBq 99mTc-sulfur colloid. There was no significant difference in the overall curves for gastric emptying time between scintigraphy and TUS-OSCA. There was a good correlation between the gastric 50% emptying times determined by scintigraphy (89.4 ± 1.8 min) and TUS-OSCA (92.5 ± 1.7 min). The correlation coefficient was r = 0.922 (p = 0.000). Current results indicate that TUS-OSCA is accurate, and the results are similar to those obtained by scintigraphy for gastric emptying of a semisolid meal.

On the validity of the 13C‐acetate breath test for comparing gastric emptying of different liquid test meals: a validation study using magnetic resonance imaging

(13) C-acetate breath testing (BT) is applied to assess and compare gastric emptying of liquid meals. Gastric half-emptying times (t50 ) from BT show offsets compared to t50 values from γ-scintigraphy and ultrasonography. Linear transformations have been proposed to correct these offsets. This investigation critically validates the BT for the assessment of liquid gastric emptying by using simultaneously recorded meal and total gastric content volume emptying data from magnetic resonance imaging (MRI). Data were collected during a recently published double-blind, randomized, cross-over MRI gastric emptying study of three (13) C-labeled enteral formulas differing in protein sources (PMID: 24699556). Breath testing-derived t50 was computed with the analysis methods commonly applied in gastric emptying research, i.e., the exponential-beta function and the Wagner-Nelson (WN) method, respectively. Breath testing t50 values from exponential-beta function and WN method showed a positive and negative offset to MRI data, respectively. Linear regression detected low concordance between MRI and both BT methods revealing meal specific and emptying rate-dependent offsets. The WN method showed worse agreement and correlation with MRI emptying data. Breath testing rather reflected meal volume than total gastric content volume emptying. This validation study indicates that the (13) C-acetate breath test may not be applied to compare gastric emptying of arbitrary liquid meals without prior validation by imaging methods. t50 values from BT are biased by (i) the properties of the meal and (ii) the selected method used for (13) CO2 exhalation analysis. No linear transformation common for all meals was applicable to correct the offsets between BT and MRI.

The effects of fasting duration on gastric emptying in man, an exploration of the role of the endocannabinoid system and inter‐individual responsiveness

In animal studies, gut vagal afferent neurons express cannabinoid (CB1) receptors, whose expression is increased by fasting. We aimed to explore the possibility that similar effects might be relevant in man in controlling gastric emptying. Fourteen healthy volunteers underwent measurements of gastric emptying using the (13) C acetate breath test, after either a nutrient (skimmed milk) or non-nutrient (water) meal following both a 12 and 24 h fast. Further gastric emptying studies were performed with and without the CB1 receptor antagonist Rimonabant (20 mg or 80 mg). Because of the inter-individual variations observed, two subjects underwent additional studies with and without Rimonabant to determine intra-individual consistency. Gastric emptying was evaluated as cumulative C13 : C12 ratio values, measured at 5 min intervals for 30 min. In the group as a whole, fasting duration slowed gastric emptying for both the nutrient [120 ± 30 (mean ± SD) vs 101 ± 34, P < 0.05] and non-nutrient [226 ± 62 vs 177 ± 47, P < 0.05] meals, but there was no effect of Rimonabant. However, there was consistent inter individual variation; thus while 12 subjects showed a slowing, two (14%) exhibited accelerated gastric emptying for both the nutrient and the non-nutrient meal after 24 h fasting and in one of whom, Rimonabant consistently reversed the fasting effect on the non-nutrient meal. Extended fasting alters the gastric emptying of liquid meals but there are consistent differences between individuals. Where there is an accelerated response to fasting, Rimonabant appears to reverse the effect.

Measurements of gastric emptying of low‐ and high‐nutrient liquids using 3D ultrasonography and scintigraphy in healthy subjects

Scintigraphy represents the 'gold standard' for the measurement of gastric emptying. Recent studies suggest that three-dimensional (3D) ultrasonography may allow a precise measure of gastric emptying, given the capacity for accurate volume calculations of the stomach. The aim of this study was to compare measurements of gastric emptying of both low- and high-nutrient drinks by 3D ultrasonography with scintigraphy. Ten healthy young subjects (6M, 4F, age 23.5 +/- 1.5 years) were studied on 2 days. Concurrent measurements of gastric emptying by scintigraphy and 3D ultrasonography were performed after ingestion of 500 mL beef soup (12 kcal) or 300 ml dextrose (25% w/v) (314 kcal) labelled with 20 MBq (99m)Tc-sulphur colloid. There was no significant difference between scintigraphic and ultrasonographic 50% emptying times (T50s) (soup: 27.7 +/- 4.8 min vs 23.8. +/- 4.8 min; dextrose: 122.2 +/- 13.3 min vs 131.9 +/- 10.2 min). There was a close correlation between scintigraphic and ultrasonographic T50s for both soup (r = 0.92, P = 0.0005) and dextrose (r = 0.88, P = 0.0007). For the T50s, the limits of agreement were -15.2 min and +8.1 min for the soup (mean difference -3.6 min) and -35.3 min and +47.6 min for dextrose (mean difference +6.2 min). 3D ultrasonography provides a valid measure of gastric emptying of liquid meals in healthy subjects.

Characterisation of α 2-adrenoceptor subtypes involved in gastric emptying, gastric motility and gastric mucosal defence

The effect of clonidine on ethanol-induced gastric mucosal damage, gastric emptying and gastric motility was compared. The clonidine-induced gastroprotective effect (0.03–0.09 μmol/kg, s.c.) was antagonised by yohimbine (5 μmol/kg, s.c.), prazosin (0.23 μmol/kg; α 2B-adrenoceptor antagonist) and naloxone (1.3 μmol/kg, s.c.). Clonidine also inhibited the gastric emptying of liquid meal (0.75–3.75 μmol/kg, s.c.) and gastric motor activity (0.75 μmol/kg, i.v.) stimulated by 2-deoxy- d-glucose (300 mg/kg, i.v.). Inhibition of gastric emptying and motility was reversed by yohimbine (5 and 10 μmol/kg, s.c., respectively), but not by prazosin (0.23 μmol/kg, s.c.) or naloxone (1.3 μmol/kg, s.c.). Oxymetazoline–an α 2A-adrenoceptor agonist–inhibited both gastric emptying (0.67–6.8 μmol/kg, s.c.) and motility (0.185–3.4 μmol/kg, i.v.), whereas it failed to affect gastric mucosal lesions. The results indicate that in contrast to the gastroprotective effect, which is mediated by α 2B-adrenoceptor subtype, α 2A-adrenoceptor subtype may be responsible for inhibition of gastric emptying and motility. However, the site of action (central, peripheral, both) remains to be established.

Reproducibility and reliability of the 13C-acetate breath test to measure gastric emptying of liquid meal in infants

Objective This study assessed the noninvasive 13C-acetate breath test ( 13C-ABT) as a reliable and reproducible method to evaluate gastric emptying in infants Methods Gastric emptying was measured simultaneously by scintigraphy and 13C-ABT in 11 infants with clinical symptoms of gastroesophageal reflux to validate the method compared with the gold standard. Gastric emptying was also measured with 13C-ABT in a separate group of 14 healthy infants on 2 consecutive days to evaluate reproducibility of the method. Half-emptying times obtained with scintigraphy and 13C-ABT were correlated with Pearson’s analysis. The variability of the half-emptying times obtained on 2 consecutive days was analyzed with paired t test and by the coefficient of variation as proposed by Bland and Altman. Results The mean emptying times obtained with scintigraphy and 13C-ABT were not different (89 ± 27 min and 70 ± 39 min, respectively, P = 0.22). Both methods correlated significantly ( r = 0.75, P < 0.05). Half-emptying times measured on 2 consecutive days with 13C-ABT were 69 ± 31 min and 68 ± 30 min, respectively (mean difference = 1.4 ± 12.4 min, P = 0.67). Intraindividual coefficient of variation was 6.3%. Conclusions This study supports the 13C-ABT method as a useful tool to evaluate gastric emptying of liquids in healthy infants and in infants with gastroesophageal reflux in the field of research and in clinical evaluations.

Forward of reverse gastric pacing do not affect gastric emptying of liquid meal in dogs

Forward of reverse gastric pacing do not affect gastric emptying of liquid meal in dogs

Forward of reverse gastric pacing do not affect gastric emptying of liquid meal in dogs

the changes in gastric motility, using electrugastrogram (EGG) and miniature pressure sensor placed in the antrum, and autonomic nerve functions after administration of CRH. [Subjects and Methods] 7 healthy volunteers participated in this study (6 male and 1 female, 18-22'].o.). EGG electrodes were attached on the bilateral mid-cravicular line of the hypochondrium and reference electrode was placed on 2cm above of the umbilicus. Dominant frequency of the EGG was calculated by FFT method. EGG frequency data were expressed as % of each range of the waves (Brady 1.6-2.4cpm, Normal 2.4-3.6cpm, Tachy >3.6). Antral manometry catheter was inserted into the gastric antrum and recorded in the data logger. Motility index (M.I.) was calculated by gastrointestinal motility software produced by White chapel Society. Heart rate variability were computed by holter ECG using FFT method and calculated LF/HF. EGG, gastric manometry and heart rate variability were recorded for 2 hr in the fasting period and 2 hr after administration of CRH (lOO/~g, bolus injection). Data, 20 minutes each, were calculated before and after CRH injection. Statistical evaluation was performed using Wilcoxon's signed-rank test. All the data were expressed as mean -+SD. [Conclusion] Peripheral injection of CRH has no influence on EGG, astral motility and sympathetic discharge in normal controls.

Effects of aging and gastric lipolysis on gastric emptying of lipid in liquid meal

Lipid delays gastric emptying, and aging is associated with changes in gastric motor function and transit. However, little is known about the effect of lipid on gastric emptying time in the elderly. To determine the effect of aging on lipid gastric emptying, we used electrical impedance tomography (EIT) to study gastric emptying of liquid meals with or without lipid in five young (23.0 +/- 0.6 years, mean +/- SEM) and six elderly (73.3 +/- 1.6 years) healthy male volunteers. These subjects drank 400 ml of non-lipid soup (triglycerides, 0 g) or lipid soup (triglycerides, 24.6g) in liquid test meals. To study the effect of lipolysis in the stomach, a liquid test meal containing 240mg of lipase in the lipid soup was also administered. Plasma cholecystokinin (CCK) concentration was measured by specific radioimmunoassay before and 30 min after the ingestion of a test meal. The gastric emptying time of the lipid soup was longer in the elderly than in the young subjects, and the time was significantly longer for lipid soup than for nonlipid soup (P < 0.05) in both the young and elderly subjects. Gastric emptying time for non-lipid soup was not significantly different between the elderly and young subjects. The administration of lipase shortened the gastric emptying time for lipid in both the elderly and the young subjects. Basal CCK concentration was significantly higher in the elderly than in the young subjects. However, there was no relationship between gastric emptying time and plasma CCK concentration after the ingestion of a test meal in the subjects overall. In conclusion, the delaying effect of lipid on gastric emptying is increased in the elderly, and the administration of lipase accelerates the emptying of lipid from the stomach.

Assessment of gastric motor function during the emptying of solid and liquid meals in humans by MRI.

Gastric emptying and motility have previously been assessed by magnetic resonance imaging (MRI) using liquid test meals. The aim of this study was to extend the applicability of our MRI method to the assessment of gastric emptying and motility of solid meals. Gastric emptying and motility of a liquid and a solid meal, of similar chemical properties, were studied in eight volunteers. The MRI protocol combined a multislice turbo spin-echo (TSE) sequence (volume scan, resolution: 1.5 mm) and a dynamic FFE sequence (motility scan, 1 sec/image, resolution: 3.1 mm). Gastric emptying of the liquid meal was faster than emptying of the solid meal when considering half-times of emptying. However, during the first 15 minutes after ingestion, the liquid meal emptied more slowly. This was related to reduced motility with the liquid meal. In conclusion, with our MRI method it is feasible to assess gastric emptying and motility of liquid and solid meals.

Faster gastric emptying of a liquid meal in rats after hypothalamic dorsomedial nucleus lesion.

The effects of dorsomedial hypothalamic (DMH) nucleus lesion on body weight, plasma glucose levels, and the gastric emptying of a liquid meal were investigated in male Wistar rats (170-250 g). DMH lesions were produced stereotaxically by delivering a 2.0-mA current for 20 s through nichrome electrodes (0.3-mm tip exposure). In a second set of experiments, the DMH and the ventromedial hypothalamic (VMH) nucleus were lesioned with a 1.0-mA current for 10 s (0.1-mm tip exposure). The medial hypothalamus (MH) was also lesioned separately using a nichrome electrode (0.3-mm tip exposure) with a 2.0-mA current for 20 s. Gastric emptying was measured following the orogastric infusion of a liquid test meal consisting of physiological saline (0.9% NaCl, w/v) plus phenol red dye (6 mg/dl) as a marker. Plasma glucose levels were determined after an 18-h fast before the lesion and on the 7th and 15th postoperative day. Body weight was determined before lesioning and before sacrificing the rats. The DMH-lesioned rats showed a significantly faster (P < 0.05) gastric emptying (24.7% gastric retention, N = 11) than control (33.0% gastric retention, N = 8) and sham-lesioned (33.5% gastric retention, N = 12) rats, with a transient hypoglycemia on the 7th postoperative day which returned to normal by the 15th postoperative day. In all cases, weight gain was slower among lesioned rats. Additional experiments using a smaller current to induce lesions confirmed that DMH-lesioned rats had a faster gastric emptying (25.1% gastric retention, N = 7) than control (33.4% gastric retention, N = 17) and VMH-lesioned (34.6% gastric retention, N = 7) rats. MH lesions resulted in an even slower gastric emptying (43.7% gastric retention, N = 7) than in the latter two groups. We conclude that although DMH lesions reduce weight gain, they do not produce consistent changes in plasma glucose levels. These lesions also promote faster gastric emptying of an inert liquid meal, thus suggesting a role for the DMH in the regulation of gastric motility.

Effect of cholecystokinin on gastric motility in humans.

Gastric emptying after food ingestion is regulated by neural and hormonal factors. However, the relative contributions of each pathway is not yet clearly defined. The classic gut hormone CCK seems to be involved in the regulation of gastric emptying in humans. Experimental evidence is best for gastric emptying of liquid meals that release CCK from the duodenum: (1) CCK infused at postprandial plasma concentrations inhibits gastric emptying of a liquid and a semisolid meal. (2) Administration of the CCK antagonist loxiglumide significantly accelerated gastric emptying of a liquid mixed meal and a glucose meal. Discrepant results with the antagonist MK329 are difficult to explain considering the marked acceleration of gastric emptying rates by the specific and potent antagonist MK329 shown in several animal studies. Taken together, current information favors the conclusion, however, that CCK mainly controls gastric emptying of the liquid but not the solid components. Thus, CCK is involved in the physiologic regulation of gastric emptying and gastric motility in man. Blocking CCK-A receptors accelerates gastric emptying of liquid meals and abolishes the gastrocolonic reflex. Therefore, CCK may play a role as a common regulator of postprandial gallbladder contraction and pancreatic enzyme secretion as well as of gastric emptying rates under certain conditions. Such common control would optimize the nutrient-to-digestive juices concentration ratio. The importance of endogenous CCK on gastric emptying of solid meals, however, is poorly understood and remains to be defined. Only very limited information is available on gastric motility. Much more work has to be done before a clear concept can be developed.

Gastric emptying of solid food is most potently inhibited by carbohydrate in the canine distal ileum

Although glucose sensors regulating the gastric emptying of liquid meals are uniformly distributed throughout the canine small intestine, some data suggest that the distal small bowel more potently inhibits gastric emptying of solid foods. The aims of this study were to compare (a) the inhibition of gastric emptying by glucose sensors in the proximal intestine with the feedback from the distal intestine, (b) these effects on the gastric emptying of solids vs. liquids, and (c) the inhibitory effect of unhydrolyzed starch with glucose. In 7 dogs with chronic duodenal fistulas, the second, third, and fourth quarters of small bowel were perfused via chronically implanted transmural catheters. Gastric emptying of either solids or liquids was tracked by γ camera while gastric output was diverted out the duodenal fistula and the small bowel perfused with test solutions of glucose (0.06–2.0 mol/L), 0.15 mol/L NaCl, or 8.5% soluble starch. It was found that (a) gastric emptying of solids but not liquids was ~3 times more potently inhibited by glucose in the fourth quarter vs. the first or second quarter of small bowel, and (b) only hydrolyzed starch inhibited gastric emptying of solids.

Relationships between oesophageal transit and solid and liquid gastric emptying in diabetes mellitus

In 87 randomly selected diabetic patients (67 type 1, 20 type 2) and 25 control subjects, gastric emptying of digestible solid and liquid meals and oesophageal transit of a solid bolus were measured with scintigraphic techniques. Gastrointestinal symptoms, autonomic nerve function and glycaemic control were evaluated in the diabetic patients. Gastric emptying and oesophageal transit were slower (P less than 0.001) in the diabetic patients compared with the control subjects, and each was delayed in about 40% of them. There was a relatively weak (r = 0.32; P less than 0.01) relationship between solid and liquid gastric emptying, and no significant correlation (r = 0.11, NS) between oesophageal transit and gastric emptying of the solid meal. Scores for upper gastrointestinal symptoms and autonomic nerve function correlated weakly (r = 0.21; P less than 0.05) with both oesophageal transit and gastric emptying. Gastric emptying of the liquid meal was slower (P less than 0.05) in patients with blood glucose concentrations greater than 15 mmol/l. These results indicate that gastric emptying in patients with diabetes mellitus should be assessed by liquid as well as by solid test meals and that oesophageal transit should not be used as a predictor of generalised diabetic gastroenteropathy.

Relationships between gastric emptying of solid and caloric liquid meals and alcohol absorption.

The effects of three variations in meal composition (a solid and a liquid meal consumed together, a liquid meal consumed alone, and a liquid meal consumed 90 min after a solid meal) on the rates and patterns of solid and liquid gastric emptying were examined in 13 volunteers. By including alcohol (0.5 g/kg body wt) in the liquid meal, the relationship between alcohol absorption and gastric emptying was also assessed. The lag phase and the initial emptying phase of the solid meal were prolonged (P less than 0.001) when the liquid meal was consumed with the solid meal, compared with when the liquid meal was consumed 90 min after the solid meal. In this latter situation, consumption of the liquid meal caused the cessation of emptying of solid food, and this second lag phase was followed by a slower (P less than 0.001) than initial emptying phase. Gastric emptying of the liquid meal was slower (P less than 0.005) when solid food was present and was slowest (P less than 0.05) when liquid was consumed 90 min after the solid meal. Alcohol absorption was fastest (P less than 0.05) when the liquid meal was consumed alone and slower (P less than 0.01) when alcohol was consumed with or after the solid meal. For all three meals there was a close correlation (r greater than or equal to 0.91; P less than 0.001) between alcohol absorption and liquid emptying. We conclude that gastric emptying of liquid may be influenced by solid food and that the rate and pattern of solid emptying may be modified by the presence of liquid.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastric emptying of liquid meals: validation of the gamma camera technique.

In order to assess the extent of errors and to provide correction factors for gamma camera gastric emptying studies of liquid meals labelled with radionuclides (99Tcm or 113Inm), a series of phantom studies were performed with different gastric emptying procedures, gamma cameras and data handling systems. To validate the overall accuracy of the method, 24 combined aspiration and gamma camera gastric emptying studies were carried out in three normal volunteers. Gastric meal volume, expressed as a percentage of the original volume of the meal ingested was underestimated due to scattered radiation from the stomach. The underestimation was 7-20% varying with the size of the gastric region of interest (ROI), the energy of the nuclide and the fraction of meal in the stomach. The overestimation, due to scattered radiation from the gut, was negligible (1-3%) for any of the procedures with 10% of the meal situated outside the stomach at a distance of at least 1 cm. Sections of the duodenal loop were always inside the stomach ROI and were likely to contain a constant fraction of the meal (3-10%). The gamma camera technique eliminated much of the error due to variations of stomach geometry and produced accurate quantitative gastric emptying data comparable to those obtained by evacuation (P greater than 0.10), when the entire field maximum 1-min count achieved within the first 20 min of a study was taken as representing the original volume of the meal ingested, and when corrections for area related errors due to scattered radiation from the stomach were performed.

Antropyloroduodenal activity during gastric emptying of liquid meals in humans.

The present study examines the possible roles of the pylorus and the proximal duodenum in the gastric emptying of two liquid meals in six healthy volunteers. Gastric emptying of a saline meal (150 mM) and an acid meal (120 mM hydrochloric acid) were measured by the double-sampling dye dilution technique while antroduodenal motility was monitored with a continuously perfused catheter system. Pyloric region pressures were measured with a Dent sleeve. The acid meal (t1/2 = 13.5 +/- 1.8 min) emptied significantly (P less than 0.01) slower than the saline meal (t1/2 = 3.5 +/- 0.7 min). This slowing in the emptying of the acid meal was associated with significant (P less than 0.05) increments in tonic pyloric activity and phasic contractions of the proximal duodenum. Thus the gastric emptying of liquid meals is a complex process involving all components of the gastroduodenal region.

Applied potential tomography: a new noninvasive technique for assessing gastric function

Applied potential tomography is a new, non-invasive technique that yields sequential images of the resistivity of gastric contents after subjects have ingested a liquid or semi-solid meal. This study validates the technique as a means of measuring gastric emptying. Experiments in vitro showed an excellent correlation between measurements of resistivity and either the square of the radius of a glass rod or the volume of water in a spherical balloon when both were placed in an oval tank containing saline. Altering the lateral position of the rod in the tank did not alter the values obtained. Images of abdominal resistivity were also directly correlated with the volume of air in a gastric balloon. Profiles of gastric emptying of liquid meals obtained using APT were very similar to those obtained using scintigraphy or dye dilution techniques provided that acid secretion was inhibited by cimetidine. Profiles of emptying of a mashed potato meal using APT were also very similar to those obtained by scintigraphy. Measurements of the emptying of a liquid meal from the stomach were reproducible if acid secretion was inhibited by cimetidine. Thus, APT is an accurate and reproducible method of measuring gastric emptying of liquids and particulate food. It is inexpensive, well tolerated, easy to use and ideally suited for multiple studies in patients, even those who are pregnant. A preliminary study is also presented that assesses the technique as a means of measuring gastric acid secretion. Comparison of resistivity changes with measured acid secretion following the injection of pentagastrin shows good correlations. APT might offer a non-invasive alternative to the use of a nasogastric tube and acid collection.

Applied Potential Tomography: A New Noninvasive Technique for Measuring Gastric Emptying

Applied potential tomography is a new, noninvasive technique that yields sequential images of the resistivity of gastric contents after subjects have ingested a liquid or semisolid meal. This study validates the technique as a means of measuring gastric emptying. Experiments in vitro showed an excellent correlation between measurements of resistivity and either the square of the radius of a glass rod or the volume of water in a spherical balloon when both were placed in an oval tank containing saline. Altering the lateral position of the rod in the tank did not alter the values obtained. Images of abdominal resistivity were also directly correlated with the volume of air in a gastric balloon. Profiles of gastric emptying of liquid meals obtained using applied potential tomography were very similar to those obtained using scintigraphy or dye dilution techniques, provided that acid secretion was inhibited by cimetidine. Profiles of emptying of a mashed potato meal using applied potential tomography were also very similar to those obtained by scintigraphy. Measurements of the emptying of a liquid meal from the stomach were reproducible i f acid secretion was inhibited by cimetidine. Thus, applied potential tomography is an accurate and reproducible method of measuring gastric emptying of liquids and particulate food. It is inexpensive, well tolerated, easy to use, and ideally suited for multiple studies in patients, even those who are pregnant.

Gastric emptying of liquids in normal subjects and patients with healed duodenal ulcer disease.

We have characterized the dose-response of inhibition of gastric emptying by acid, glucose, and fat in duodenal ulcer (DU) patients and normals (N) matched by age and sex. Gastric emptying was measured by the George technique while intragastric pH was maintained constant by intragastric titration. Acid, glucose, and fat inhibited gastric emptying in a dose-dependent fashion in both groups. DU patients emptied all three types of meals faster than normals, but differences were only seen at the lower doses of glucose or with the less potent doses of acid and fat. With low concentrations of glucose and at all concentrations of acid, DU patients emptied the meals faster than normals only in the first 5 min; but with fat the differences persisted throughout the 30-min test. Differences in gastric emptying of liquid meals in DU patients vs normals are small, and they occur with nutrient as well as acid meals. The variable responses obtained with the different concentrations may explain the inconsistencies found by other workers.