Gastric emptying after truncal vagotomy and pyloroplasty

We have studied the gastric (fundic and antral) emptying of solids and liquids by a radionuclide method in 20 patients after truncal vagotomy and pyloroplasty (TVP) and in 10 control subjects. Gastric emptying of solids in TVP patients was similar to that of the control group (NS), but fundic emptying did not show a lag phase and was significantly faster. A significantly higher percentage of the solid fraction of the test meal filled the antrum (32 +/- 16% versus 20 +/- 9%; p less than 0.05), and this quantity was constant during the study period. Gastric emptying of liquids was greatly hastened after surgery. In 22 min 50 +/- 16% had left the stomach (versus 40 +/- 14% in controls; p less than 0.001). At 90 min the amount of liquid remaining in the stomach was similar to that in the control subjects. TVP accelerates fundic emptying of solids, which are transferred to an overfilled, paretic antrum. Liquids are emptied by a bimodal pattern with a precipitous initial emptying followed by a second slower phase.     

Symptomatic,radionuclide and therapeutic assessment of chronic idiopathic dyspepsia

Twenty-eight patients with chronic idiopathic dyspepsia defined by the presence of chronic unexplained symptoms suggestive of gastric stasis and directly related to food ingestion were included in this prospective study. Gastric emptying of the liquid and solid phases of a meal was quantified by a dual-isotope method, and symptoms were evaluated by a diary and a visual analog scale. Delay in gastric emptying was evidenced in 59% of the dyspeptic patients; it occurred with liquids in more cases than solids. Quantitative and qualitative evaluation of symptoms was of no practical value in predicting the presence of objective stasis. The dyspeptic patients were included in a double-blind randomized controlled trial of cisapride, a new gastrokinetic drug devoid of central antiemetic effects. After six weeks of cisapride treatment, all patients with initially abnormal gastric emptying rates for liquids, and all but one for solids returned to normal ranges, and significant differences between cisapride and placebo groups were observed for half emptying times of both solids (136 +/- 16 min vs 227 +/- 32 min; P less than 0.02) and liquids (61 +/- 4 min vs 132 +/- 37 min; P less than 0.01). Cisapride also significantly improved dyspeptic symptom scores at weeks 3 and 6 of treatment as compared to those measured before treatment. Nevertheless, the decrease in global diary score was significantly higher than that seen with placebo at week 3 (-16 +/- 6 vs -1 +/- 9; P less than 0.05), but not at week 6 (-18 +/- 5 vs -10 +/- 8).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of the increase of the caloric load of a meal on gastric emptying of its solid and liquid phases

Caloric regulation of gastric emptying was mainly assessed with artificial liquid meals. We thus studied the effects of glucidic and lipidic caloric loads on gastric emptying of a solid-liquid meal (400 ml; 480 kcal), measured by an isotopic technique. Sixteen healthy subjects were separated in 3 groups; solutions of identical volume (400 ml) were added to the meal: water in group I (N = 6), glucose polymers (Caloreen; 400 kcal) in group II (N = 5), and triglycerides (Intralipide; 400 kcal) in group III (N = 5). Gastric emptying was dramatically slower in groups II and III than in group I, whatever the parameter considered. The magnitude of this caloric brake was identical for the 2 caloric loads tested and concerned both phases of the meal. Therefore, 3 h after the end of the meal, intragastric percentages of ingested liquids were 50 +/- 4 in group II, 52 +/- 5 in group III, vs 14 +/- 1 p. 100 in group I (p less than 0.001); for solids these percentages were 56 +/- 6 and 68 +/- 2 vs 11 +/- 3 p. 100 (p less than 0.001). In all groups, emptying of solids was slower than that of liquids, but the kinetics of this discrimination was modified by the increase of caloric load. The pyloric output of calories, estimated for the 3 h of the study was close to 2 kcal/min for the 3 groups studied. Thus, the 2 fold increase of the caloric concentration in groups II and III as compared to group I, did not modify the delivery rate of energy to small bowel.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative study of gastric emptying of digestible and nondigestible solids in normal man and duodenal ulcer patients

Few studies have compared the gastric emptying of digestible and non-digestible solids in man. In 9 normal subjects and 16 duodenal ulcer patients, we measured simultaneously and during 3 h, the gastric emptying of: (a) radioopaque pellets (n = 100; volume = 30 mm3) ingested with an ordinary meal (450 kcal, 500 ml) and counted on X-ray series; and (b) digestible solids of the meal (99mtechnetium tagged egg white) detected by an isotopic method. Gastric emptying of liquids (labelled with 113mindium DTPA) was also determined. In normal subjects, emptying rates of the pellets was 5 +/- 2 p. 100 per hour while that of digestible solids was 29 +/- 1 p. 100 per hour (P less than 0.01). No correlation was evidenced between the emptying rates of either kind of solids. Emptying of liquids was faster than that of both digestible solids and pellets. Similar results were obtained in duodenal ulcer patients; no significant difference was found between patients and normal subjects for the three meal phases tested. These results are consistent with the hypothesis that digestible solids are retained in stomach until they are ground, and show that inert particles do not always reflect the gastric emptying of natural solids of the meal.     

Gastric emptying in patients with bulimia nervosa and anorexia nervosa

A dual radioisotope technique was used to measure gastric emptying of a mixed liquid and solid meal in 11 patients with bulimia nervosa, and was compared with 10 patients with anorexia nervosa and a sex-matched control population. The relationship of body weight and gastrointestinal symptoms to gastric emptying was also examined. Gastric emptying of solids in patients with bulimia nervosa was similar to that in controls (gastric T1/2 131 +/- 15 min vs 119 +/- 7 min; mean +/- SEM). In contrast, patients with anorexia nervosa had overall delayed emptying (182 +/- 31 min; p less than 0.05); six patients had normal emptying of the solid components of the meal and four had markedly delayed emptying. Gastric emptying of liquids was similar in the bulimics and controls (gastric T1/2 48 +/- 5 min and 49 +/- 4 min, respectively), whereas the anorexics tended to have prolonged gastric emptying (65 +/- 11 min, p = NS). There was no correlation between body weight, gastrointestinal symptoms, and gastric emptying in either group. These findings suggest that gastrointestinal symptoms are unreliable indicators of gastric emptying in patients with eating disorders, and that gastric emptying studies should be performed in such patients before treatment with prokinetic agents is considered.     

Clinical relevance of scintigraphic measurement of gastric emptying of a solid-liquid meal in the dumping syndrome.

Gastric emptying of the solid and liquid components of an ordinary meal was evaluated by a dual isotopic technique in 36 patients referred to our hospital for early postprandial symptoms induced by various esophageal and/or gastric operations. Patients were classified as typical (n = 11), equivocal (n = 9) or improbable (n = 16) dumpers, in accordance with their presenting symptoms, as assessed before gastric emptying measurement. Patients with typical dumping symptoms displayed, as expected, significant acceleration of gastric emptying of liquids (t1/2: 18 +/- 6 min. vs. 48 +/- 7 min. in healthy controls; p less than 0.02), and also exhibited a dramatic enhancement of gastric emptying of solids (t1/2: 11 +/- 1 min. vs. 126 +/- 12 min. in healthy controls; p less than 0.001) and a complete loss of solid-liquid discrimination (7 +/- 6 min. vs. 78 +/- 7 min. in healthy controls; p less than 0.01). Mean gastric emptying rates for equivocal and improbable dumpers were not significantly different from those of healthy controls, but individual results were very heterogeneous; they included stasis, acceleration, or both disorders, and were not predictable by analysis of symptoms alone. Thus gastric emptying of solids as well as liquids is accelerated in symptomatic dumping patients, and objective evaluation of the emptying of both solid and liquid gastric emptying is essential in atypical dumpers, in order to characterize their disorders and prescribe the most rational treatment.     

Effect of fundus vagotomy on the gastric emptying of the solids and liquids of a meal in patients with and without postoperative duodenal ulcer recurrence

The effects of fundic vagotomy (FV) on gastric emptying in the solid and liquid phases of a meal were studied by an isotopic technique in 12 patients with duodenal ulcer. Postoperative results were compared with those obtained in the same subjects before FV and with control values obtained in an identical group of healthy subjects. Early gastric emptying (perprandial) of the two phases of the meal was enhanced by FV but the results failed to reach statistical significance. Gastric emptying of liquids, measured during the 3 h following the end of the meal, was not significantly modified by FV (half-emptying times: 62 +/- 5 min before FV, 75 +/- 8 min after and 65 +/- 7 min for controls). That of solids was significantly delayed by FV (per cent emptied by min: 0.50 +/- 0.02 p. 100 before FV, 0.40 +/- 0.03 p. 100 after, and 0.49 +/- 0.02 p. 100 for controls); this delay was found in all but one patient, but the difference was very slight. Eleven of the 12 investigated patients cured by the operation, were compared with 6 subjects presenting with post FV recurrence: gastric emptying rates of solids (0.41 +/- 0.02 p. 100/min and 0.47 +/- 0.07 p. 100/min) and half emptying times of liquids (72 +/- 10 min and 61 +/- 10 min) were not significantly different. Thus, the gastric emptying rate of an ordinary meal remains practically unchanged by FV and postoperative recurrences of duodenal ulcer cannot be explained by alteration of gastric evacuation.     

Sequence of morphological and hemodynamic changes of gastric microvessels in portal hypertension.

Changes in gastric microvasculature and blood flow at different phases of portal hypertension were studied in rats 1, 2, 3, 4, and 15 days after induction of portal hypertension or sham operation. Vessel lumen and vessel wall thickness were expressed as a ratio referred to the vessel size. On day 2 after constriction of the portal vein, gastric blood flow was decreased (0.57 +/- 0.06 vs. 0.99 +/- 0.20 mL.min-1.100 g-1; P less than 0.05), and gastric vessels had a distended lumen (0.42 +/- 0.02 vs. 0.28 +/- 0.03; P less than 0.01) and a thin wall (2.11 +/- 0.2 vs. 3.82 +/- 0.4; P less than 0.01). On day 4, the gastric blood flow of portal hypertensive animals was increased (1.15 +/- 0.14 vs. 0.71 +/- 0.07 mL.min-1.100 g-1; P less than 0.05), whereas gastric vessels had a reduced lumen (0.27 +/- 0.02 vs. 0.33 +/- 0.02; P less than 0.01) and a thick wall (4.19 +/- 0.52 vs. 3.16 +/- 0.30; P less than 0.05). By day 15, vessels with the largest lumens (0.45 +/- 0.01 vs. 0.29 +/- 0.01; P less than 0.01) and the thinnest walls (1.78 +/- 0.26 vs. 3.58 +/- 0.62; P less than 0.01) were observed in portal hypertensive animals. In conclusion, the gastric vessels of the 15-day portal vein-ligated rat resemble the structural abnormalities described in human portal hypertensive gastropathy.     

Opposite effects of kappa-opioid agonists on gastric emptying of liquids and solids in dogs

The influence of oral (p.o.) administration of kappa-(U-50488, tifluadom) and mu- (morphine, DAGO) opioid substances on gastric emptying of liquids and solids in a standard canned dog food meal was evaluated using a double-radiolabeled technique in dogs fitted with gastric cannulas. One hour after feeding, 28.6% +/- 3.6% (mean +/- SD) of the solid phase and 27.1% +/- 8.6% of the liquid phase of the meal had been emptied. Both U-50488 and tifluadom given orally (0.01-0.1 mg/kg) significantly increased (p less than 0.05) the 1-h emptying of the solid phase of the meal by 23.1%-49.6%. In contrast, both drugs significantly reduced emptying of liquids. These effects were not reproduced when similar doses were given intravenously. Oral administration of morphine or DAGO (0.01-0.1 mg/kg) did not affect gastric emptying, whereas an inhibited emptying of solids was observed for morphine at a higher dose (1 mg/kg p.o.). At a dose of 100 micrograms/kg i.v. both naloxone and MR 2266 (0.1 mg/kg) abolished the effects of orally administered U-50488 on gastric emptying of solids and liquids. It is concluded that kappa- but not mu-agonists act locally to alter gastric emptying of a standard meal in dogs, having opposite effects on solid and liquid phases. A selective local stimulation of kappa mucosal or submucosal receptors of the gastroduodenal area may explain such effects.     

Propranolol reduces ethanol-induced gastric mucosal damage in portal hypertensive rats

In a standardized rat model of portal hypertension, we investigated the effects of propranolol on alcohol-induced gastric mucosal damage. Portal hypertensive rats pretreated with 2 mg propranolol, compared with those receiving saline, had significantly reduced portal pressures (24 +/- 1 vs 32 +/- 1 cm saline), macroscopic mucosal damage (24 +/- 1 vs 39 +/- 4% of mucosa), and histologic deep necrosis (36 +/- 2 vs 61 +/- 4% of mucosal length). Increased dosage of propranolol to 4 mg did not produce any further reduction of portal pressure or mucosal damage. Central venous and systemic arterial pressures were not significantly altered by propranolol. The extent of mucosal damage correlated with levels of portal pressure (P less than 0.01) in portal hypertensive rats. Sham-operated normotensive rats had less macroscopic mucosal damage (26 +/- 4%) than portal hypertensive rats, and propranolol did not affect the extent of ethanol-induced damage or portal pressures in these animals. We conclude: (1) Propranolol is effective in reducing extent of ethanol-induced gastric mucosal damage in portal hypertensive rats, but not in sham-operated controls; (2) this effect correlates with reduction of portal pressure; and (3) our study supports the clinical impression that reducing portal pressure may be one approach for the prevention and therapy of gastric mucosal damage in portal hypertension.     

Liquid and solid gastric emptying in adults treated for Hirschsprung's disease during early childhood

OBJECTIVE: Dysmotility of the upper gastrointestinal tract has been reported in children with Hirschsprung's disease. In the present study, gastric emptying was studied in adult patients with Hirschsprung's disease to elucidate whether there is a persisting involvement of the upper gastrointestinal tract in this group of patients. MATERIAL AND METHODS: Gastric emptying of caloric liquids and solids was studied in 16 adult patients with surgically treated Hirschsprung's disease during early childhood and in age-matched controls. To examine liquid emptying, the paracetamol absorption test was applied using a meal containing glucose, lactose, maize oil, water (2020 kJ) and paracetamol. To examine solid emptying, the 13C gastric emptying breath test was applied using a meal containing white bread, margarine, a one-egg omelette (1050 kJ) and [13C]-octanoic acid. Gastrointestinal symptoms were recorded according to a standardized questionnaire. RESULTS: For liquid meal emptying, the time until emptying commenced was 8.1+/-1.9 and 2.9+/-0.9 min (mean+/-SE) in patients and controls, respectively (p=0.02). Thereafter, the first 25% of the meal emptied in 6.8+/-0.8 and 12.1+/-1.1 min in patients and controls, respectively (p=0.0005). The overall emptying rate tended to be delayed in patients compared with controls (p=0.06). For the solid meal, a delay in emptying was evident (p=0.02). The patients reported more symptoms from the upper gastrointestinal tract than the controls, but the symptoms were not significantly related to the emptying pathology demonstrated. CONCLUSIONS: The present study demonstrates that adult patients with Hirschsprung's disease have an abnormal pattern of gastric emptying, indicating persisting involvement of the upper gastrointestinal tract.     

Gastric emptying and its relationship to antral contractile activity.

Gastric emptying and antral contractile activity were simultaneously measured in 3 dogs with gastric and duodenal fistulas. Contractile activity was monitored by two force strain gauge transducers on the serosal surface of the antrum of 2 dogs and a single strain gauge transducer on the serosal surface of both the antrum and fundus of the 3rd dog. Both the frequency and force (motility index) of antral contractions were determined for each 1 min period. Gastric emptying and contractile activity were recorded and compared minute by minute with test meals (154 mM saline) of 60, 120, 240, and 480 ml. Although the rate of gastric emptying increased with the frequency and force of antral contractions, up to 67 ml min-1 (mean 6.9 ml min-1) were emptied without measurable antral contractile activity and 0 to 96 ml min-1 (mean 19.4 ml min-1) were emptied during maximal antral activity (minute motility index greater than 119 mm). Antral contractile activity increased with the size of the test meal and decreased expoentially with the rate of gastric emptying. Fundal contractile activity was generally absent during the test meal. These studies suggest that although the antrum has a significant role in the emptying of liquids, other undefined factors may modify its effect on gastric emptying.     

Biphasic nature of gastric emptying.

The existence of a lag phase during the gastric emptying of solid foods is controversial. It has been hypothesised that among other early events, the stomach requires a period of time to process solid food to particles small enough to be handled as a liquid. At present no standardised curve fitting techniques exist for the characterisation and quantification of the lag phase or the emptying rate of solids and liquids. We have evaluated the ability of a modified power exponential function to define the emptying parameters of two different solid meals. Dual labelled meals were administered to 24 normal volunteers. The subjects received meals consisting of either Tc-99m in vivo labelled chicken liver or Tc-99m-egg, which have different densities, and In-111-DTPA in water. The emptying curves were biphasic in nature. For solids, this represented an initial delay in emptying or lag phase followed by an equilibrium emptying phase characterised by a constant rate of emptying. The curves were analysed using a modified power exponential function of the form y(t) = 1-(1-e-kt)beta, where y(t) is the fractional meal retention at time t, k is the gastric emptying rate in min-1, and beta is the extrapolated y-intercept from the terminal portion of the curve. The length of the lag phase and half-emptying time increased with solid food density (31 +/- 8 min and 77.6 +/- 11.2 min for egg and 62 +/- 16 min and 94.1 +/- 14.2 min for chicken liver, respectively). After the lag phase, both solids had similar emptying rates, and these rates were identical to those of the liquids. In vitro experiments indicated that the egg meal disintegrated much more rapidly than the chicken liver under mechanical agitation in gastric juice, lending further support to the hypothesis that the initial lag in emptying of solid food is due to the processing of food into particles small enough to pass the pylorus. We conclude that the modified power exponential model permits characterisation of the biphasic nature of gastric emptying allowing for quantification of the lag phase and the rate of emptying for both solids and liquids.     

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 gamma 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 approximately 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.     

Relationship between impaired gastric emptying and abnormal gastrointestinal motility

The mechanism of gastric stasis in disorders of gastrointestinal motility is largely unexplored. The region or regions of abnormal motility in 13 patients with a gastrointestinal motility disorder were characterized manometrically. Antral hypomotility was established in 6 patients and intestinal dysmotility in 7 others. One patient had both antral hypomotility and intestinal dysmotility. Gastric emptying of solids and liquids was quantitated scintigraphically; emptying data for solids were represented by a two-phase model (lag and emptying) and for liquids by a power exponential model. Antral hypomotility was associated with gastric stasis manifested by both a prolongation of the solid lag time [from 35 +/- 6 min for controls to 87 +/- 23 min (mean +/- SE), p less than 0.05] and slower emptying rates of solids (from a slope index of 29.9 +/- 2 for controls to 17.8 +/- 5, p less than 0.05) and liquids (from a kappa index of 3.6 +/- 0.6 for controls to 1.5 +/- 0.5, p less than 0.05). Intestinal dysmotility did not alter the solid lag time; however, it did decrease the slope of solid emptying from the stomach (from a slope index of 29.9 +/- 2 for controls to 13.5 +/- 3, p less than 0.05) and also prolonged emptying of liquids (from a kappa index of 3.6 +/- 0.3 for controls to 1.9 +/- 0.6, p less than 0.05). These data are consistent with the hypothesis that the gastric stasis in gut dysmotilities occurs because of impaired antral peristalsis due to antral hypomotility or increased resistance to flow into the small bowel due to intestinal dysmotility.     

Influence of gender and menopause on gastric emptying and motility

The aims of this study were to determine (a) if there are differences in gastric emptying rates of a mixed liquid and solid meal between men and women, (b) if menopausal status affects gastric emptying, and (c) whether differences in solid emptying rates are associated with alterations in postprandial antral motility parameters. A dual-isotope technique was used to measure gastric emptying in 20 men, 18 premenopausal women, 14 postmenopausal women, and 8 postmenopausal women taking estrogen and progesterone hormone replacement. A multilumen perfusion catheter was used to measure antral motility in 6 men and 6 premenopausal women. Premenopausal women, postmenopausal women, and postmenopausal women taking oral estrogen and progesterone had slower gastric emptying of liquids than did men (p less than 0.025, less than 0.05, and less than 0.025, respectively). Both premenopausal women and postmenopausal women taking sex hormone replacement therapy had slower emptying of solids than did men (p less than 0.025 and less than 0.05) but, in contrast to liquids, postmenopausal women not on hormone replacement emptied solids at a rate similar to that of men. There were no differences in postprandial antral motility parameters between men and premenopausal women. These findings support the hypothesis that sex steroid hormones have variable inhibitory effects on gastric emptying of a mixed meal and this should be considered when studying gastric emptying in disorders that occur predominantly in premenopausal women.     

Antroduodenal motor response to solid-liquid and homogenized meals.

The effect of the physical state of food on antroduodenal motor activity and the pattern of the emptying of an aqueous phase marker were examined in 6 healthy volunteers using an intestinal perfusion technique and intraluminal pressure transducers. Ingestion of a solid-liquid meal produced marked phasic changes in pressure in the distal antrum, lasting 92 +/- 10 min (mean +/- SE), while, in contrast, ingestion of the same nutrients in a homogenized state resulted in complete absence of distal antral changes in pressure lasting 133 +/- 12 min. The motor responses of the proximal antrum and duodenum were similar for the two meals. Both meals emptied during a 3-hr period, the pattern of emptying of the aqueous phase marker being similar for the two meals except for the first 40 min, when emptying was more rapid after the solid-liquid meal. The homogenized meal emptied despite the absence of changes in distal antral pressure. The gastrin response was similar for the two meals and is therefore not responsible for the different patterns of antral motility and gastric emptying.     

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.     

Relationship between the effects of cisapride on gastric emptying and plasma glucose concentrations in diabetic gastroparesis

BACKGROUND/AIMS: The effect of erythromycin on gastric emptying is attenuated during hyperglycaemia. The aim of this study was to determine in patients with diabetic gastroparesis whether the effect of cisapride on gastric emptying of solids and liquids is influenced by the plasma glucose concentration. METHODS: Nineteen patients with type 1 diabetes mellitus, who had delayed gastric emptying of solids and/or liquids, were studied. On 2 separate days, each patient received cisapride (20 mg) or placebo orally 60 min before scintigraphic measurement of gastric emptying of a mixed solid (ground beef) and liquid (dextrose) meal. The plasma glucose concentrations were measured at -5, 30, 60, 90, and 120 min during each gastric emptying measurement. RESULTS: Cisapride accelerated both solid (retention at 100 min 43 +/- 4 vs. 69 +/- 4%, p < 0.001) and liquid (T50 27 +/- 2 vs. 39 +/- 2 min, p < 0.001) gastric emptying. The mean plasma glucose level was not significantly different after placebo when compared with cisapride (19.5 +/- 1.1 vs. 18.2 +/- 1.0 mmol/l). The change in the 50% emptying time (T50) for liquid, but not solid, emptying was related (r = 0.55, p = 0.01) to the change in the plasma glucose AUC from 0 to 30 min between the placebo and cisapride tests, i.e., the acceleration was greater if the plasma glucose concentration was relatively less during the gastric emptying test performed on cisapride. CONCLUSION: The effect of cisapride on gastric emptying, at least that of liquids, in patients with diabetic gastroparesis appears to be dependent on the plasma glucose concentration.     

Gastric emptying of indigestible tablets in relation to composition and time of ingestion of meals studied by metal detector

Enteric-coated tablets leave the stomach mainly during the interdigestive phase. Composition as well as time of ingestion of meals may influence their gastric emptying considerably. In 12 normal volunteers gastric emptying of a plastic tablet with a metal core was followed by a metal detector in relation to different compositions and various times of ingestion of meals. With an empty stomach and after ingestion of 250 ml water, the mean time for gastric emptying of the tablet was 38 +/- 11 min (mean +/- SEM) and 38 +/- 8 min. Two hundred fifty milliliters of milk (652 kJ) and a formula diet (1000 kJ) delayed gastric emptying time to 128 +/- 14 and 152 +/- 6 min, respectively (P less than 0.05). Breakfast (2200 kJ) further retarded gastric emptying compared with both liquids to 249 +/- 24 min (P less than 0.05). There was a close correlation between nutritive density and gastric emptying of the tablet (r = 0.92; P less than 0.001). Main meals also delayed gastric emptying of tablets when compared to empty stomach (P less than 0.05). A snack after breakfast further delayed gastric emptying from 201 +/- 10 to 278 +/- 19 min (P less than 0.05). The largest delay was observed following ingestion of breakfast, lunch, dinner, and additional snacks (509 +/- 220 min). We conclude that the delay of gastric emptying of enteric-coated tablets by food is related to its nutritive density and eating habits. The gastric emptying of an enteric coated tablet that is ingested early in the morning may be delayed until late at night when several meals and snacks are ingested during the day, leading to unwanted alterations in bioavailability and to possible adverse effects.