Effects of meal composition on gallbladder and gastric emptying in man

Cholecystogastric scintigraphy, utilizing [^99mTc]HlDA to label the gallbladder contents and [¹¹¹In]DTPA to label different meals, was utilized to determine the relationships between gallbladder and gastric emptying after meals of differing composition. Gallbladder emptying was determined in response to a multicomponent meal and to monocomponent fat, carbohydrate, and protein meals and in response to isotonic and hypertonic dextrose and isotonic and hypertonic saline. Also, the gallbladder emptying responses to equivalent multicomponent solid and liquid meals were compared. Significant gallbladder emptying was observed in response to the multicomponent meal and the monocomponent fat, carbohydrate, and protein meals. The most rapid and complete gallbladder emptying was seen with the multicomponent meal and the monocomponent fat meal. Significant gallbladder emptying was stimulated, not only by isotonic and hypertonic dextrose, but also by hypertonic saline. The gallbladder emptied more rapidly after a liquid than after a solid meal.     

Progression of changes in gastric emptying of hypertonic liquids after proximal gastric vagotomy

Gastric emptying rates of hypertonic (10%) dextrose liquid meals were studied in five dogs before, and 3, 6, and 12 months after proximal gastric vagotomy (PGV) without drainage. The purpose of this study was to determine if operation-related changes in emptying rates normalized or became more disparate during the year after PGV. An increased rate of emptying during the first 5 min after ingestion was seen at 3 months after PGV, which significantly increased (P<0.025) after 6 and 12 months. The remainder of the meal after PGV emptied at a regulated exponential rate unchanged throughout the postoperative year from its preoperative rate. Total volumes of gastric aspirate at four intervals after meal ingestion did not significantly change across the four test periods in respect to endogenous secretion or pH acidity.Supported by The Veterans Administration.     

Effects of nutrients on gastrointestinal motility and gastric emptying after distal gastrectomy with Roux-Y gastrojejunostomy in dogs

The aim of the study was to clarify whether nutrients are still capable of slowing gastric emptying following Roux-Y gastrectomy, as in normal dogs. Gastrointestinal motility and gastric emptying of acaloric and nutritive meals with different viscosities were measured in normal dogs and after a two-thirds Roux-Y gastrectomy. In gastrectomized dogs low-viscosity nutritive meals emptied unduly rapidly in an initial phase, although the frequency and spread of contractions, ie, the propulsive activity of the jejunal Roux limb were diminished. A slow emptying rate during the following period was due to a long-lasting inhibition of gastric and jejunal motility. Medium-viscosity nutritive meals emptied in gastrectomized dogs as slowly as in normal animals, but this effect was primarily caused by the meal viscosity and only secondarily by the nutrients. It is concluded that following Roux-Y gastrectomy a regulation of gastric emptying is preserved; however, the onset of an effective control is delayed, resulting in a rapid initial emptying of low-viscosity meals.Studies were supported by the Deutsche Forschungsgemeinschaft grant Eh 64/3-1.     

Gastric emptying after gastric bypass

Gastric emptying of two test meals, consisting of ground beef and water and ground beef with 25 percent dextrose was measured with a scintigraphic technique in patients after gastric bypass surgery and in control subjects. Solid emptying was slower and liquid emptying was more rapid after gastric bypass and 25 percent dextrose emptied as rapidly as water. The pattern of gastric emptying after gastric bypass would favour more rapid initial absorption with liquid calories and may also be implicated in the dumping syndromes sometimes seen after gastric bypass.     

Pancreatobiliary responses to an intragastric amino acid meal: comparison to albumin, dextrose, and a maximal cholecystokinin stimulus

Little is known about how gastric and pancreatobiliary responses differ after intake of elemental diets from responses to polymeric food. We therefore compared pancreatic and biliary secretions after gastric instillation of albumin (7 g%, with dextrose 21 g%) with an elemental diet in 6 healthy volunteers. The elemental diet contained amino acids (7 g%, with dextrose 21 g%) in the same molar composition as the albumin. Furthermore, we studied the effect of a pure intragastric dextrose solution (21 g%) on pancreatobiliary secretions, as glucose constitutes a major component of elemental diet formulas. The various pancreatobiliary responses were tested against a maximal i.v. cholecystokinin stimulus. The dextrose, amino acid, and albumin meals emptied at similar rates, and gastric emptying was completed within 3 h. Similar pancreatobiliary responses were observed after the albumin and amino acid meals, but response to both the amino acid and albumin meals was smaller than to the intravenous cholecystokinin stimulus. The glucose meal caused a marked and sustained stimulation of pancreatobiliary outputs, which did not differ significantly from the other test meals. However, lower cholecystokinin levels were observed after the glucose meal compared with distinct cholecystokinin release after the albumin and amino acid meals. We conclude first that there are no major differences in secretory responses between elemental (amino acid) and polymeric (protein) meals and second, that intragastric pure glucose meals strongly stimulate pancreatobiliary secretions. The marked pancreatic and biliary responses to intragastric dextrose cannot be fully explained on the basis of cholecystokinin release, suggesting that this response is probably mediated by neural mechanisms.     

Absorption of acetylsalicylic acid from unbuffered and buffered gastric contents

Test meals of 200 ml containing acetylsalicylic acid or buffered acetylsalicylate were given to 19 healthy subjects. Studies were made of the rate of gastric emptying and the gastric absorption of acetylsalicylic acid. It was found that the buffered acetylsalicylate test meals (pH 7.0) were emptied more rapidly from the stomach than test meals containing unbuffered (pH 2.8) acetylsalicylic acid. After 10 min, considering the means of amounts of aspirin absorbed, there was at least 10 times less absorbed from the buffered solution. No bleeding into the gastric contents was observed in response to any test meal.Supported by Miles Laboratories, 1127 Myrtle St, Elkhart, Ind 46514.The authors are grateful to the subjects for their cooperation, and to Miss J. Boram, and Miss D. Porter for technical assistance and are indebted to Drs. W. E. Goldstein and C. L. Sutula of Ames Company Division, Miles Laboratories Inc. for the computation underlying the maximal and minimal values of Table 2. An account of their methods is being prepared for publication.     

Superior mesenteric artery blood flow and gastric emptying in humans and the differential effects of high fat and high carbohydrate meals.

This study was designed to determine if the differential effect of high fat and high carbohydrate meals on mesenteric blood flow is a result of changed gastric emptying rate. Eight healthy men were studied twice. Superior mesenteric artery blood flow (Doppler ultrasound) was measured before and after a 2.5 MJ meal (either 74% of the energy as carbohydrate or 71% as fat). Emptying of meals was followed by gamma-scintigraphy. The pattern of the superior mesenteric artery blood flow response was different after the two meals (interaction effect p < 0.001 analysis of variance), with a far more sustained response after fat. The time by which half the meal had emptied (t50) was also significantly greater after fat (p < 0.02). Superior mesenteric artery blood flow corresponding to t50 was 449 ml/min after carbohydrate and 592 ml/min after fat. There was a significant curvilinear relation between the superior mesenteric artery blood flow response and gastric emptying after carbohydrate (r2 = 0.94) and no relation at all after fat. This study confirms the finding that ingestion of meals with a high fat content slows gastric emptying compared with meals with a high carbohydrate content in healthy volunteers. A more sustained mesenteric hyperaemia was also recorded after the fat meal compared with the carbohydrate meal. The relation, however, between the volume of meal remaining in the stomach and the mesenteric response was considerably different after the two meals. Further study is required to elucidate the mechanism behind the vascular responses recorded in the mesenteric bed after food in humans.     

Role of the proximal and distal stomach in mixed solid and liquid meal emptying.

The role of the proximal and distal stomach in the emptying of solids and liquids from the stomach remains unclear. We have used a dual isotope technique to quantify proximal and distal stomach emptying of a solid (100 g of 99mTc labelled liver/ground beef) liquid (either 200 ml of normal saline (eight subjects) or 25% dextrose (seven subjects) labelled with 113mIn-diethylenetriaminepenta-acetic acid) mixed meal. A manometric catheter simultaneously measured antral, pyloric, and duodenal motor activity. The liquid component dispersed rapidly throughout the stomach and emptied after a minimal lag period. The emptying of the 25% dextrose was delayed compared with the saline. This delay was associated with increased retention of the liquid in the distal stomach, a significant increase in localised phasic pyloric contractions, and a suppression of antral contractions. The solid component initially resided wholly within a proximal stomach reservoir area. Solids then redistributed from proximal to distal stomach during the emptying of liquid from the stomach. Dextrose delayed gastric emptying of solids compared with saline by increasing the solid lag period and retention in the proximal stomach. There was no significant difference between saline and dextrose meals in the distal stomach retention of solid or in the linear rate of emptying after the lag period. We conclude that, contrary to general opinion, the proximal stomach plays an important role in the control of gastric emptying of solids while the distal stomach is important in the emptying of nutrient liquids.     

Gastric emptying of oil from solid and liquid meals

Digestion of fat in pancreatic insufficiency (PI) is strongly affected by how rapidly fat enters the duodenum. We postulated that: (1) oil empties faster in PI than in normals and (2) in both, it empties in a load-dependent fashion. We used a gamma camera to test these ideas by comparing gastric emptying of iodine-123 iodinated oil in normal and pancreatic-insufficient subjects after 15 g of free oil were ingested in a small spaghetti meal and 60 g of oil were ingested in a large spaghetti meal and in a milk emulsion. Indium-113m marked gastric emptying of water in the milk. In both groups after all meals, oil emptied fastest initially, slowing later; and oil emptied three to four times faster when 60 g vs 15 g were ingested. There were no significant differences between the groups of subjects with respect to gastric emptying of the spaghetti meals, but the pancreatic-insufficient subjects emptied both oil and water faster from the milk emulsion than did the normal subjects. The slower emptying of oil in the normal subjects was associated with significantly more layering of oil to the top of the intragastric milk emulsion.     

The volumetric measurement of gastric emptying and gastric secretion by a radioisotope method

Most methods of measurement of gastric emptying rely on the serial estimation of intragastric volume and do not separately account for the volume of fluid which has been added to the meal by gastric secretion, duodenal reflux, or swallowed saliva. The volume emptied is therefore underestimated. A method of measuring gastric emptying using [¹²⁵I]RIHSA and the Volémetron is presented. The volume of fluid added to the meal is taken into consideration in this method, giving a more accurate reflection of gastric emptying. Using this method in the dog, emptying was found to be linear rather than exponential.Supported by South African Medical Research Council grant M14/71/51.     

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.     

Gastric emptying after roux-y and billroth-I gastrectomy depends on viscosity of meal and contractile patterns of small intestine in dogs

The aim of the study was to examine gastrointestinal motility after distal gastrectomy and the influence of meal viscosity on gastric emptying. Gastrointestinal motility and gastric emptying of acaloric meals with different viscosities were measured in normal dogs and after a two-thirds gastrectomy with Billroth-I or Roux-Y gastroenterostomy. After distal gastrectomy, gastric emptying depended on the viscosity of the meal, as in normal dogs. Acaloric viscous meals emptied significantly faster in the Billroth-I than in the Roux-Y group due to different contractile patterns of the duodenum and jejunum. In comparison to normal dogs, gastric emptying of viscous meals was accelerated in the Billroth-I and delayed in the Roux-Y group. Several motility parameters of the stomach and intestine differed between the normal and gastrectomized dogs. Thus, after distal gastrectomy, the viscosity of the meal and the contractile patterns of the small intestine are important determinants of gastric emptying.Studies were supported by the Deutsche Forschungsgemeinschaft, grant Eh 64/3-1.     

Relation between gastric emptying rate and energy intake in children compared with adults.

Measurement of gastric emptying rate of solids in children is difficult because the available methods are either invasive or induce a substantial radiation burden. In this study the newly developed 13C octanoic acid breath test was used to examine the gastric emptying rate of solids and milk in healthy children and to compare gastric emptying in children and adults. Fifteen healthy children and three groups of nine healthy adults were studied, using three different test meals labelled with 50 mg of 13C octanoic acid: a low caloric pancake (150 kcal), a high caloric pancake (250 kcal), and 210 ml of milk (134 kcal). Breath samples were taken before and at regular intervals after ingestion of the test meal, and analysed by isotope ratio mass spectrometry. The gastric emptying parameters were derived from the 13CO2 excretion curves by non-linear regression analysis. No significant difference was found between children and adults in the emptying rate of the low caloric solid test meal. In children as well as in adults, increasing the energy content of the solid meal resulted in a significantly slower emptying rate. The milk test meal, however, was emptied at a faster rate in adults and at slower rate in children compared with the low caloric solid test meal. Moreover, the emptying rate of milk in children was significantly slower than in adults. In conclusion, a similar gastric emptying rate of solids but a slower emptying of full cream milk was shown in children of school age compared with adults, using the non-radioactive 13C octanoic acid breath test.     

Gastrointestinal function in obesity: motility, secretion, and absorption following a liquid test meal.

Digestive responses to a 300-mL liquid fat-rich meal (432 kcal) in a group of massively obese patients were compared with those observed in a group of healthy lean subjects of variable body weight. Gastric and intestinal propulsion, digestive secretions, and absorption in the proximal 70 cm of intestine were measured using a multiple-marker dilution method. The average gastric emptying of energy, acid, volumes, and meal marker were similar in the two groups 80 minutes after intake, justifying a comparison of intestinal processing of the meal. Compared with lean subjects, the obese subjects responded with less pancreatic secretion (P less than .05) and gallbladder emptying, but absorbed a larger proportion of the emptied energy in the test segment (P less than .01) during a similar or shorter transit time. In addition, when the entire meals were compared, the obese group generally absorbed the test meal more effectively and rapidly in the upper part of the intestine. As a consequence, the flow volumes at the exit of the test segment were lower (P less than .05), and less of the test meal was propulsed to distal parts of the intestine. In the lean subjects, the body weight or height correlated positively with the gastric emptying rate, peak gastric acid output, and pancreatic responses, and negatively with (P less than .05) the segment transit time. The taller the subject, the greater the proportion of the meal which was rapidly propulsed unabsorbed to lower parts of the intestine, indicating that a large intestinal area was exposed for rapid energy uptake. No such correlations were observed in the obese group.     

Real-time ultrasonographic assessment of antroduodenal motility after ingestion of solid and liquid meals by patients with functional dyspepsia

BACKGROUND AND AIMS: Although antroduodenal motility has usually been studied by using manometric or scintigraphic methods, ultrasonography is an established, non-invasive method to evaluate duodenogastric motility. We used ultrasonography to evaluate gastric motility in patients with functional dyspepsia. METHODS: Sixty-four patients with functional dyspepsia and 36 asymptomatic healthy subjects were given liquid and solid test meals. We investigated the gastric emptying rate, motility index, and duodenogastric reflux for the liquid meal and gastric emptying time, half-emptying time, and motility index for the solid meal. RESULTS: After the liquid meal, the gastric emptying rate and motility index were significantly lower and the duodenogastric reflux was significantly higher in functional dyspepsia patients than in healthy subjects. After the solid meal, gastric emptying time, half-emptying time and the motility index were significantly lower in the patients than in the healthy subjects. Delayed gastric emptying of both meals occurred in only 20.3% of patients. Delayed emptying of the liquid or solid meal occurred in 62.5% of patients. In both groups, gastric emptying time of the solid meal was positively correlated with the motility index at 15 min post-ingestion. CONCLUSION: In functional dyspepsia patients, delayed gastric emptying of a solid meal was related to antral hypomotility during the early postprandial phase. Ultrasonographic assessment of gastric motility in both liquid and solid meals may provide a better understanding of the pathogenesis of functional dyspepsia.     

Relation between gastric emptying of albumin-dextrose meals and cholecystokinin release in man

The effect of intragastric dextrose on albumin-stimulated cholecystokinin (CCK) release was studied in five healthy subjects and was related to gastric emptying and pancreatobiliary secretions. When combined with low concentrations of dextrose (4 g/100 ml), a 500-ml solution of albumin (7 g/100 ml) was rapidly emptied from the stomach into the duodenum (T1/2: 35 min). This rapid gastric emptying resulted in an only transient stimulation of pancreatobiliary secretion and an integrated CCK release of 278±45 pM × 180 min. When the concentration of dextrose in the albumin solution was increased from 4 g/100 ml to 21 g/100 ml, gastric emptying rate was distinctly slower (T1/2: 78 min;P<0.01) and pancreatobiliary secretions became sustained (P<0.01). CCK release was markedly higher (900±421 pM × 180 min;P<0.05) after ingestion of the solution containing a high dextrose concentration. Intraduodenal infusion of 21 g/100 ml dextrose (3.1 ml/min) failed to significantly stimulate plasma CCK levels (119±38 pM × 120 min). We suggest that the higher CCK release in response to intragastrically administered albumin solution containing high concentrations of dextrose may have been induced by augmented peptic digestion of albumin due to delayed gastric emptying and by increased enteral digestion of albumin due to increased pancreatobilary outputs.     

Effect of vagotomy on gastric emptying

To determine whether pyloroplasty or a disrupted osmoreceptor mechanism is primarily responsible for the increased gastric emptying of hypertonic sugar solutions after vagotomy and pyloroplasty, test meals of 10% glucose (556 mOsm/kg) and NaCl (200 mOsm/kg) were administered to duodenal ulcer patients with no prior operation, after vagotomy and pyloroplasty, and in patients with prior vagotomy, hiatal herniorrhaphy, and no pyloroplasty. Hypertonic glucose meals were emptied more rapidly than normal after both operations. The hypotonic NaCl meal was emptied no faster postoperatively than it was preoperatively. The results rule out pyloroplasty as the primary factor responsible for the observed increased rate of gastric emptying. Instead, the data suggest that the osmoreceptor mechanism described by Hunt is disrupted by vagotomy.Presented in part at the Midwestern Section. American Federation for Clinical Research, Chicago, Ill. Nov 1, 1969.Supported by Veterans Administration Part II Research Funds.     

Different gastric,pancreatic, and biliary responses to solid-liquid or homogenized meals

We have compared responses to an ordinary solid-liquid (S) meal and to a homogenized (H) meal of identical composition (sirloin steak, bread, butter, ice cream with chocolate syrup, and water) by measuring simultaneously postprandial gastric, pancreatic, and biliary functions by marker-perfusion techniques. Responses to each (S or H) meals differed strikingly both in magnitude and pattern. S meals elicited a stronger early gastric secretory response (acid, pepsin, and volume) which compensated for faster initial emptying and resulted in higher gastric acidity and volume than after H meals. Further, nutrients ingested with S meals were emptied at a slower rate than H (as evidenced by a more gradual decline in intragastric buffer and osmolality, as well as time required for complete emptying of the meal). This, in turn, prolonged pancreatic and biliary responses since stimulation of these organs continued for as long as meal was delivered into the duodenum. However, early biliary outputs (gallbladder response) were less after S than H, probably because nutrients entered the duodenum more slowly and were initially diluted by rapidly emptying water. The physical characteristics of each meal (encompassing appearance, taste, and form of ingestion) probably accounted for early differences in digestive responses. Later, interactions between gastric (motor and secretory), pancreatic, and biliary functions played a major role. Our findings suggest that gastric, pancreatic, and biliary responses to liquid test meals introduced into the stomach may differ substantially from the presumably more physiological response to ordinary solid-liquid meals.Dr. Summerskill died March 9, 1977.This investigation was supported in part by Research Grant AM 6908 from National Institutes of Health.     

Relationship of the motor activity of the antrum, pylorus, and duodenum to gastric emptying of a solid-liquid mixed meal

The postprandial motor activity of the antrum, pylorus, and duodenum in 15 healthy volunteers was compared with the profiles of emptying of the solid and liquid components of a meal. The liquid component of the meal emptied rapidly in an exponential manner, whereas the solid remained in the fundus of the stomach until approximately 80% of the liquid had emptied and then emptied in a linear manner. The onset of solid emptying was associated with an increase in the rate of occurrence of antral pressure waves (p less than 0.05), and the half-time for solid emptying (t1/2 - lag period) was inversely correlated (p less than 0.05) with the rate of coordinated contractions involving the antrum. The substitution of 25% dextrose in normal saline as the liquid component of the meal increased the half-time for liquid emptying from a median of 8 to 40 min (p less than 0.01), increased the lag period for solid emptying from 40 to 87 min (p less than 0.01), and increased the rate of occurrence of isolated pyloric pressure waves during the solid lag phase from 7 to 58/h (p less than 0.05), but did not affect the slope of solid emptying or the rate of coordinated contractions involving the antrum during the solid emptying period.     

Effect of intragastric volume and osmolality on mechanisms of gastroesophageal reflux in children with gastroesophageal reflux disease

OBJECTIVE: Both transient lower esophageal sphincter (LES) relaxations (TLESRs) and periods of low/absent LES pressure (LESP) are the main mechanisms of gastroesophageal reflux. These events are believed to be triggered by stimuli from different areas of the upper GI tract. We aimed at investigating the relationship between LESP profile and gastric emptying and distension after meals of different composition in 30 children with gastroesophageal reflux disease (median age 7.0 yr, range 12 months-12 yr). METHODS: Recordings of LESP and intraesophageal pH for 1 h fasting and for 2 postprandial h were performed with a perfused sleeve catheter and flexible electrode, respectively; gastric emptying and distension of antral area were simultaneously recorded with real-time ultrasonography. Ten patients had a standard meal (group A), 10 had a high-volume meal (group B), and 10 had a high-volume and osmolality meal (group C). RESULTS: Postprandial esophageal acid exposure was significantly higher in patients of groups B and C than in patients of group A (p < 0.01); it was also more prolonged in patients of group C than in subjects of group B (p < 0.05). A higher postfeeding rate of reflux episodes caused by TLESRs was detected in patients of groups B and C as compared with patients of group A (p < 0.01). This increase did not statistically differ in patients of groups B and C. Patients of group C exhibited a higher postprandial rate of reflux episodes associated with low/absent tone of the LES as well as a more prolonged gastric emptying time and a higher postfeeding gastric distension as compared with patients of groups A and B (p < 0.01). Finally, a significant correlation was only found between the postprandial rate of reflux events resulting from low/absent LESP and the degree of antral distension in patients of group C (p < 0.01). CONCLUSION: Gastroesophageal reflux is worsened by increasing the volume and osmolality of meals through significant changes of LESP. Meals of high volume and meals with high volume and osmolality cause a comparable increase of reflux episodes as a result of TLESRs. However, meals with high volume and osmolality cause the higher degrees of esophageal acid exposure than meals with high volume resulting from a higher rate of reflux episodes associated with low/absent LESP. This finding correlates with a high postfeeding antral distension.