Gallbladder contraction and its relationship to interdigestive duodenal motor activity in normal human subjects

Gallbladder volume and interdigestive gastric and duodenal motor activity were evaluated simultaneously in 12 normal subjects. After overnight fasting, gallbladder volume was monitored every 4 min in each subject by means of real-time ultrasonography, and gastroduodenal motor activity was measured by means of a probe consisting of three polyvinyl catheters with one side opening for each catheter, placed 15 cm apart and constantly perfused with deionized water. Real-time ultrasonography and intestinal manometry were performed by different investigators and continued until at least two consecutive spontaneous phase III activities of migrating motor complexes were observed. The results show a cyclic variation of gallbladder volume, which reached its minimum value before the end of phase II in the proximal duodenum and its maximum in early phase II, 25 min after the beginning of phase III. These results suggest that there is a relationship between the cyclic gallbladder volume changes, which occur during fasting in humans, and with the various phases of duodenal migrating motor complex.     

Gastric acid inhibits antral phase III activity in duodenal ulcer patients

Fourteen patients with duodenal ulcers and eight healthy volunteers were examined to measure interdigestive gastroduodenal motility and plasma motilin. In order to study the effects of gastric acid on the gastroduodenal motility, 20 mg of famotidine was administered intravenously. The motility index of the gastric antrum and the duodenum, as well as the pH in the duodenal bulb were calculated. The duodenal pH was significantly lower and the gastric motility index was significantly weaker before the duodenal interdigestive migrating complex (IMC) in the ulcer patients than in the controls. Motilin levels increased before the duodenal IMC and decreased afterwards in both groups. Famotidine significantly increased the duodenal pH and the gastric motility index before the IMC, but no changes in the motilin level were noted. We conclude that duodenal ulcer patients have duodenal hyperacidity that results from increased inflow from the antrum and antral hypomotility during the gastric IMC and that these changes are normalized by the administration of famotidine. These results suggest that gastric acid inhibits antral contraction during the gastric IMC.     

Upper gastrointestinal motor activity in patients with slow-transit constipation

Recent evidence indicates that patients complaining of severe chronic idiopathic constipation may have motor abnormalities not limited to the colon. We studied by manometric means gastric and small bowel motility in a homogeneous group of patients with chronic idiopathic constipation ie, the slow transit type. Twenty-one patients were recruited for the study and compared to 33 healthy subjects. Manometric examination was carried out for about 5 hr fasting and 1 hr after a standard meal. Analysis of the manometric tracings revealed during fasting no abnormalities in number and configuration of migrating motor complex with respect to controls. However, in 70% of patients motor abnormalities were detected, represented by bursts of nonpropagated contractions and discrete clustered contractions. After feeding, the patient group displayed a significantly shorter antral motor response to the meal with respect to controls; moreover, intestinal bursts of nonpropagated contractions were found in 19% of patients, and 14% of them had an early return of the activity fronts. We conclude that patients with slow transit constipation frequently display motor abnormalities of the upper gut. These findings further strengthen the concept that this condition may represent a panenteric disorder.     

Antroduodenojejunal motor activity in untreated and treated celiac disease patients

Background and Aim:  Patients with celiac disease may present with abnormal upper gut motor activity. However, it is not known if these abnormalities persist after the introduction of a gluten-free diet. The present study aimed to compare antroduodenojejunal motor variables recorded in untreated celiac patients with those of celiac patients given a gluten-free diet and healthy volunteers.
Methods:  Eleven untreated celiac disease patients, 12 age- and sex-matched celiac patients on a gluten-free diet (at least 12 months), and 33 controls entered the study. Antroduodenojejunal motility was recorded for 6 h during fasting and for 3 h after a standard meal by means of a perfused, multiple lumen catheter.
Results:  More than 80% of untreated celiac patients had discrete motor abnormalities of the upper gut, in both fasting and fed recordings, compared to the other subjects. Patients on a gluten-free diet also showed motor abnormalities, albeit to a lesser extent. In these patients histological evaluation showed the persistence of mild mucosal abnormalities.
Conclusions:  Upper gut motor abnormalities are frequent in patients with celiac disease, even in those on a gluten-free diet. In the latter group, these abnormalities may suggest an incomplete adherence to the dietary regimen.     

Abnormalities in the shape of the duodenal loop on x-ray

We aimed to determine if abnormalities in the shape of the duodenal loop would be useful in identifying patients with gastroduodenal dysmotility. Retrospectively, 126 consecutive patients with suspected functional abdominal symptoms who underwent upper gastrointestinal barium x-ray studies and gastrointestinal manometry were independently evaluated. Twenty-seven patients (21%) had an abnormally shaped duodenal loop (two proximal and 25 distal) by x-ray. An abnormal duodenal loop was associated with female gender but the presenting symptoms were similar in patients with normal and abnormal loops. Antral hypomotility was significantly more common in patients with distal duodenal malrotations compared to those with a normal x-ray (56% vs 27%,P<0.01); intestinal dysmotility was not associated with the shape of the duodenal loop. The presence of an abnormally shaped duodenal loop in patients presenting with functional gastrointestinal symptoms may be a useful marker for idiopathic antral hypomotility.     

An evaluation of an ambulatory manometry system in assessment of antroduodenal motor activity

While abnormalities in antroduodenal motor function have been documented in both organic and functional disorders, controversy surrounds the ideal manometric technique. We sought, therefore, to evaluate a digital solid-state ambulatory system. Sixteen normal volunteers underwent 24-hr recordings of antroduodenal motility. Following catheter placement, a standardized meal was ingested in the laboratory; thereafter, subjects were ambulatory and assumed normal diet and activities. The system was well tolerated; subjects reported that it did not affect their usual activities. Migrating motor complex (MMC) activity was identified in each subject (mean frequency: 4.1 MMCs/24 hr, range 1–8); on average 1.9 (range 0–4, frequency 0.1/hr) occurred while awake and 2.1 (range 0–5, 0.3/hr,P<0.05 vs awake) during sleep. The fed response was evaluated by calculating a motility index (MI) at 30-min intervals from 30 min before to 120 min following meal ingestion. Postprandially, MI was maximal during the first 30 min following meal ingestion: MI (mean±sd) 30 min before vs 30 min after meal in the antrum: 4.16±1.42 vs 5.33±0.72 (P<0.05), duodenum: 4.04±0.80 vs 4.57±0.47 (P<0.05), respectively. None of the other postprandial intervals were significantly different from baseline. There was no significant difference in MI between the standard andad libitum meals. Retrograde catheter migration (mean 5.6, range 1–10 cm) occurred in relation to all meals; as a consequence, antral recordings were lost following 60% of all meals, thereby limiting meaningful analysis of the antral fed response. We conclude, firstly, that while an ambulatory antroduodenal manometry system is well tolerated and reliably records duodenal motility, postprandial catheter migration limits antral recordings, and, secondly, that a motility index calculated during the first 30 min following anad libitum meal accurately reflects the fed motor response.Supported in part by the University of Nebraska Hospital.     

Gastric acid response to modified sham feeding in patients with duodenal ulcer: Is increased vagal tone the cause of basal acid hypersecretion?

In order to test the hypothesis that increased basal vagal tone causes basal acid hypersecretion in duodenal ulcer (DU), the effect of sham feeding on gastric acid secretion was studied in 26 patients with DU and 20 healthy controls. Basal acid output (BAO), sham feeding-stimulated acid output (SAO) and peak histamine-stimulated acid output (PAO) were significantly higher in DU patients compared with healthy controls (P less than 0.01). The BAO/PAO ratio in DU patients (0.28 +/- 0.03) was not significantly different from that of healthy subjects (0.19 +/- 0.03), indicating that the higher BAO in DU patients group, as a whole, was due to a higher parietal cell mass. The basal subtracted response to sham feeding expressed as a fraction of secretory capacity [(SAO-BAO)/PAO], which correlates inversely with the basal vagal tone, was not significantly different in the patients and control subjects (0.27 +/- 0.03 versus 0.3 +/- 0.03; P greater than 0.05). Based on the data from the healthy controls, a ratio of BAO/PAO greater than 0.44 was defined as abnormal (using 95% confidence limits) and it indicated marked basal acid hypersecretion. Four of 26 DU patients had basal acid hypersecretion (that is, BAO/PAO greater than 0.44), but only two of them did not show an increase over their basal rate of secretion in response to sham feeding. All other DU patients, including two with marked basal acid hypersecretion, and all healthy controls showed an appreciable increase in their acid secretion in response to sham feeding.(ABSTRACT TRUNCATED AT 250 WORDS)     

Real-time evaluation of dyspeptic symptoms and gastric motility induced by duodenal acidification using noninvasive transnasal endoscopy

Background  Although different pathophysiological mechanisms have been suggested to be involved in functional dyspepsia, a practical method to clarify them has not been established. The aim of this study was to evaluate dyspeptic symptoms and gastric motility induced by duodenal acidification using transnasal endoscopy. Methods  Fourteen healthy volunteers (mean age, 32 years) were enrolled. Transnasal endoscopy was performed on all fasting volunteers. Dyspeptic symptoms and antral contractions were evaluated before and after duodenal infusions of pure water (20 ml/min for 5 min) and acid (0.1 N HCl, 20 ml/min for 5 min). The severity of various symptoms was assessed by each subject using a 10-cm visual analog scale every 2 min. The maximum severity scale was calculated as the mean of the individual maximum values. The motility number was defined as the mean number of antral contractions in 1 min. Results  The maximum severity score for a heavy feeling in the stomach and other symptoms significantly increased after the acid infusion compared with after the pure water infusion. During pure water infusion, there were no changes in the motility number. On the other hand, the motility number significantly decreased after duodenal acidification (before vs. after, 2.93 ± 0.12 times vs. 1.11 ± 0.23 times, P < 0.0001). Conclusions  Duodenal acid exposure induces dyspeptic symptoms and inhibits antral motility. Transnasal endoscopy enabled us to evaluate both dyspeptic symptoms and gastric motility simultaneously.     

Integration of canine proximal gastric,antral, pyloric,and proximal duodenal motility during fasting and after a liquid meal

The aim was to investigate the integration of proximal gastric, antral, pyloric, and duodenal motility during fasting and after feeding. Using a proximal gastric barostat and a manometric assembly with an array of side holes astride the gastroduodenal junction, the gastrointestinal interdigestive migrating motor complex was detected in five of seven conscious fasting dogs. During phase III of the complex, which lasted a mean ± SEM of 13 ± 0.5 min, 9.6 ± 0.9 volume waves were present in the proximal stomach. The volume waves were coordinated with clusters of antral waves 64 ± 11% of the time and with inhibition of duodenal waves 91±3% of the time. A 300-ml calorie-dense liquid meal abolished the complex and promptly increased proximal gastric volume in five of six dogs. Volume waves were nearly completely suppressed, while antral waves decreased from 24 ±3.0 waves/10 min to 10±2.8 waves/10 min (P<0.05) and isolated pyloric pressure waves increased from 7.2±2.8 waves/10 min to 22±3.3 waves/10 min (P<0.005). In summary, proximal gastric motility was integrated with antral, pyloric, and duodenal motility under both fasting and fed conditions. The integrated patterns likely account for the efficient clearance of indigestible solids during fasting and the controlled emptying of nutrients with feeding.Supported in part by USPHS NIH Grants DK 18278, DK34988, and DK07198, the Winthrop Travelling Fellowship of the Royal Australasian College of Physicians, the S.K.F. (Australia) Travelling Fellowship, and the Mayo Foundation.This work was presented in part before the World Congress of Gastroenterology, Sydney, Australia, August 30, 1990     

Gastric ulcers differ from duodenal ulcers evaluation of basal acid output

Patients with pyloric channel and prepyloric gastric ulcers are often considered to have an ulcer diathesis similar to patients with duodenal ulcers, while patients with more proximal gastric ulcers (ie, fundus, body, antrum) are excluded. To evaluate possible differences in basal acid outputs with regard to gastric ulcer location, basal acid outputs were determined by nasogastric suction in 80 patients with endoscopically documented benign active gastric ulcers. The results were compared to 65 normal subjects and 155 patients with endoscopically documented duodenal ulcers. There were no significant differences in basal acid outputs among the 80 patients with gastric ulcers with regard to location (ie, fundus-body, antrum, prepyloric, channel), and no significant differences compared to the 65 normal subjects. However, basal acid output for the 155 patients with duodenal ulcers was significantly different from the 80 patients with gastric ulcers (P<0.05) and the 65 normal subjects (P<0.05). Basal acid outputs tended to be higher and there was more gastric acid hypersecretion when gastric ulcers were located near the pylorus. However, irrespective of gastric ulcer location, basal acid outputs were higher in patients with duodenal ulcers. Seventy-one of the 80 patients with gastric ulcers were treated for eight weeks with standard doses of antisecretory medications, and endoscopic healing or nonhealing was documented. In 60 patients their gastric ulcers completely healed, while 11 patients had nonhealed gastric ulcers. There were no significant differences between the two groups with regard to gender, mean age, or basal acid output. The gastric acid secretory profiles determined in this study do not appear to support the view that prepyloric and pyloric channel gastric ulcers are similar to duodenal ulcers.     

Gastric acid secretion in a child with postbulbar duodenal ulcer

A 14-year-old case was reported with a primary postbulbar duodenal ulcer, which was confirmed by barium meal study and duodenoscopy. In the preoperative study, the patient showed marked gastric hyperacidity: maximal and peak acid output were 0.980 and 1.434 mEq/kg/hr, respectively. As previously described, hyperacidity appears to be a main factor in the pathogenesis of postbulbar duodenal ulcer. Fasting and postprandial serum gastrin secretion was not thought to be responsible for gastric hyperacidity in the present case. Upon histological investigation, the operatively resected stomach did not suggest a possible relationship between hyperacidity and an enlarged parietal cell mass.     

Gall-bladder and sphincter of Oddi response to cholecystokinin in the Australian possum

The effects of cholecystokinin octapeptide (CCK-OP) on the gall-bladder (GB) and sphincter of Oddi (SO) of the Australian brush tailed possum were examined in 45 anaesthetized animals. CCK-OP (20-640 ng/kg) consistently caused the GB to contract in a dose-dependent manner (Kruskal Wallis P less than 0.05). In 20 animals, the same dose range of CCK-OP produced an excitatory response in the SO, increasing the SO motility index (MI = frequency of contractions x mean peak amplitude) dose-dependently (Kruskal Wallis P less than 0.05). In five animals, an inhibitory response, that is, a decrease in MI, was recorded, with 640 ng/kg of CCK-OP producing a 50% decrease in MI. In the remaining 20 animals, variable responses of both excitation and inhibition were elicited within the same animal. The action of CCK-OP on the SO and GB was not modified by atropine, phentolamine or propranolol. Tetrodotoxin (TTX) reversed the inhibitory responses of the SO to CCK-OP such that responses were excitatory (sign test P less than 0.05). TTX did not alter the response of the GB to CCK-OP. It is concluded that CCK-OP acts directly on smooth muscle receptors of the GB. In the SO, its action is mediated via non-cholinergic, non-noradrenergic inhibitory neurons and also by a direct excitatory action on the smooth muscle of the SO.     

Central and peripheral serotonergic influences on viscerovisceral inhibitory reflex during duodenal distension in sheep

The effects of duodenal distension on forestomach and abomasal motility were investigated in conscious sheep chronically fitted with intraparietal electrodes, a duodenal cannula, and an intracerebroventricular cannula. Duodenal distensions with a balloon inflated with 40 ml (DD40) of water reduced the frequency of forestomach and abomasal contractions by 45 and 32%, respectively, while distension with 80 ml (DD80) induced a total inhibition. Methysergide, a mixed 5HT₁-5HT₂ antagonist administered intravenously (200 g/kg) or intracerebroventricularly (20 g/kg) suppressed the DD40-induced inhibition and reduced that induced by DD80. Sprioxatrine, a selective 5HT_1A antagonist, intravenously (100 g/kg) or intracerebroventricularly (10 g/kg), suppressed the DD40 and DD80-induced inhibition, which was also attenuated by the 5HT₂ antagonist ritanserin given intravenously (200 g/kg) or intracerebroventricularly (20 g/kg). Granisetron, a 5HT₃ antagonist, injected intravenously (150 g/kg), abolished the effects of DD40 and DD80 while it had no antagonistic action on DD40 and DD80 when given intracerebroventricularly (15 g/kg). It is concluded that in sheep, duodenal distension inhibits forestomach and abomasal motility through 5HT_1A and 5HT₂ receptors at the level of the central nervous system and 5HT₃ receptors located peripherally.This work was presented in part at the First United European Gastroenterology Week, September 25–30, 1992, Athens, Greece.     

Reducing meal-stimulated acid secretion versus reducing nocturnal acid secretion for healing of duodenal ulcer

Both meal-stimulated and nocturnal acid secretions have been shown to be abnormally increased in patients with duodenal ulcer. The relative efficacy of an acid-reducing regimen aimed specifically at controlling postprandial acid secretion compared with one that controls nocturnal acid secretion is, however, not known. The endoscopic healing rates at weeks 2, 4, 6, 8, 10, and 12 of three cimetidine regimens with identical total daily dose—bedtime (1200 mg), mealtime (400 mg three times a day with meals), and reference (200 mg three times a day with meals and 600 mg at bedtime)—were compared in a randomized study on 141 patients with endoscopically proven duodenal ulcer. Evaluating endoscopists were blinded to patients' form and duration of treatment and their clinical progress; patients were unaware of the comparative design of the study. Life-table analysis for the 12 weeks of observation revealed that the mealtime regimen resulted in significantly (P<0.05) better healing rates than either the bedtime or the reference regimen. The differences were accounted for largely by the significantly (P<0.04) better healing rate at two weeks with the mealtime regimen (68%) than with either the bedtime (47%) or the reference (45%) regimen. These findings indicate that a regimen that aims at controlling meal-stimulated acid secretion achieves a faster healing rate than one that aims at controlling nocturnal acid secretion in the treatment of duodenal ulcer, and they suggest that postprandial acid secretion plays a greater role than nocturnal acid secretion in the pathophysiology of this condition.This study was supported by the Peptic Ulcer Research Fund (311/041/0372), and by grants (311/030/8009/31, 311/030/8010/12, 335/041/0006, 311/030/8010/69) of the University of Hong Kong.     

Esophageal motor function in patients with myotonic dystrophy

To investigate pharyngeal and esophageal motor function in myotonic dystrophy (MD), and its relationship to esophageal symptoms, we used low-compliance, high-fidelity esophageal manometry and videofluorography to evaluate 14 consecutive MD patients. Patients exhibited a consistent, typical motor pattern, involving a marked reduction in resting tone of both the upper and lower esophageal sphincters, and a reduction in contraction pressure in the pharynx and throughout the esophagus. Radiology showed hypotonic pharynx with stasis and a hypo- or amotile, often dilated, esophagus. These findings were nonspecific, however, being present in patients both with and without dysphagia, which suggests that MD patients have valid compensatory mechanisms. Dysphagia only correlated to the pharyngeal impairment at manometry. Furthermore, the results of our study suggest that not only the proximal, striated part of the gullet, but also the distal part (in which smooth muscle dominates) is involved in the disease. The latter leads to the impairment of the LES resting tone and competence, highlighting the risk of gastroesophageal reflux disease in these patients.This work has been supported, in part, by grant 94.02522.CT04 from the Italian National Research Council.     

Manometric patterns of rat colonic motor activity and defecation

We investigated in conscious and unrestrained rats, the major patterns of colonic pressure waves, as related to defecation. A manometric low compliance perfusion system, which was set at a very low flow rate (0.03 ml/min), permitted simultaneous recordings of intraluminal pressure in the proximal, transverse, and distal colon. Pressure waves in control rats reflected two types of motor activity: short-duration waves (<15 sec), that were frequent throughout the colon (about 40–90/hr with aborally decreasing frequency), and propulsive, long-duration, high-amplitude waves (>15 sec, >15 mm Hg) that occurred only occasionally (1/hr or less) in the transverse and distal, but not in the proximal colon; these waves appeared to migrate aborally and were associated with defection. The serotonin 5HT_1A agonist 8-OH-DPAT dramatically and dose-dependently increased the frequency of long-duration, high-amplitude waves in the transverse and distal colon, and concurrently promoted defecation; these effects were prevented by the putative 5HT_1A antagonist pindolol. We conclude that 5HT_1A agonists such as 8-OH-DPAT may promote defecation and occurrence of propulsive waves through the same serotoninergic mechanism.A preliminary account of this work was presented at the 13th International Symposium on Gastrointestinal Motility, Kobe, Japan, Abstract 172. J Gastrointest Motil 3, 1991.     

Monthly variation in frequency of active duodenal ulcer and maximal acid output

The frequency of duodenal ulcer has been reported to vary seasonally. It is not known whether gastric acid secretion of patients with this condition has similar seasonal variation. During 1981–85, 1864 patients (mean age 38.0 years, s.d. = 24.2, males comprising 67.1%) with newly diagnosed active duodenal ulcer were documented endoscopically. Of these 626 patients (mean age 38.5 years, s.d. = 15.0, males comprising 71.4%) agreed to have their basal acid output (BAO) and pentagastrin-stimulated maximal acid output (MAO) measured. Time series analysis using the frequency domain approach identified that the monthly frequencies of duodenal ulcer over the 5-year period occurred in cycles of 12 months. Multiple comparison using Duncan's procedure identified the occurrence of a significant peak in November and December. MAO varied significantly ( P < 0.04) with season with two peaks, one occurring in February and another in July. Month-adjusted MAO was significantly higher ( P < 0.001) in male than in female patients. BAO showed no significant variation by month. It is concluded that active duodenal ulceration and MAO manifest significant variation by month, but their peaks do not coincide, indicating that acidity is unlikely to be a major factor responsible for the frequency of duodenal ulcer peaking in winter. These results also suggest that it is advisable to adjust for seasonal variation when MAO is compared among groups of duodenal ulcer patients.     

Effect of proximal gastric vagotomy on serum pepsinogen I and II concentrations and acid secretion in duodenal ulcer patients

Acid secretion and basal serum pepsinogen I and II concentrations were measured in 14 duodenal ulcer patients before and at intervals up to six years after proximal gastric vagotomy. Vagotomy led to significant and long-standing reductions in basal, vagally mediated (induced by sham feeding), and peak pentagastrin-stimulated acid secretion. Serum pepsinogen I concentrations also decreased significantly after vagotomy but to a significantly lesser extent than acid secretion. There was no correlation between serum pepsinogen I concentrations and peak acid secretion, either before or after vagotomy. Serum pepsinogen II concentrations decreased only slightly and transiently after vagotomy. Thus, proximal gastric vagotomy reduces acid hypersecretion and pepsinogen I hypersecretion, but not pepsinogen II hypersecretion, in duodenal ulcer patients. This work was supported by a grant from the Veterans Administration, the National Institutes of Health (AM 16816), and the Berta M. and Cecil O. Patterson Endowment Fund in Digestive Disease.     

Effect of smoking on gastric acid secretion in patients with duodenal ulcer

The effect of smoking on gastric secretion was studied in 15 consecutive patients with duodenal ulcer--six normosecretors (basal acid output less than or equal to 3 mEq/h), and nine hypersecretors (basal acid output greater than 3 mEq/h). The volume, acid output, acid concentration, and pH of the gastric juice measured before, during and after 1 h of smoking did not show any significant difference in these patients taken as a single group, or when the normosecretors and hypersecretors were analysed as separate groups (P greater than 0.05 for each parameter in each group). The higher acid output before and during smoking in hypersecretors than in normosecretors was due to the higher acid concentration in the gastric juice (P less than 0.01). Study of the pH curves of the gastric juice after acute smoking showed that hypersecretors had a lower pH for a longer duration compared with normosecretors. This could make the hypersecretors with a history of chronic smoking more prone to developing duodenal ulcer.     

Effect of pacing on small intestinal motor activity and hormonal response in dogs

In seven beagle dogs with a Thiry-Vella loop, the effect of pacing on small intestinal motor activity was examined by means of extraluminal strain gauge force transducers. Recordings were obtained from the loop and from the remaining small intestine. Our study showed that pacing of the loop results in a significant reduction of the motility of the loop in the overnight fasted state (up to 39%), during loop feeding (up to 55%), and oral feeding (up to 39%); a similar reduction of the motility of the remaining small intestine (up to 43%); and a significant postprandial increase of insulin (9.0 U/ml) and decrease of glucagon (94 pg/ml). The motility reduction of the loop and of the remaining small intestine as well as the anabolically improved pancreatic endocrine function (shown by an increase of the insulin — glucagon ratio) suggests that this form of pacing could be of benefit for motility disorders with decreased transit time.The present study was supported by Deutsche Forschungsgemeinschaft.