Biomedical subjects

E S Björnsson

Publications and source records attributed to E S Björnsson.

At least 19 recordsLinked to original sources

PubMed2007

Nutrient-dependent enhancement of rectal sensitivity in irritable bowel syndrome (IBS).

Food-related gastrointestinal symptoms are common in irritable bowel syndrome (IBS), but the mechanisms behind this are unclear. Enhanced colorectal sensitivity after duodenal lipid administration in IBS patients has been demonstrated. However, the effects of a regular meal on colorectal sensitivity in these patients and the importance of the composition of the meal are not known. On two separate days, 10 IBS patients and 11 controls randomly received a liquid meal (800 kcal), containing 60% calories from fat (fatty meal) or carbohydrate (carbohydrate meal). Using a barostat rectal sensitivity was assessed during four separate distension sequences before, immediately after and 30 and 60 min after the meal. In the patients, the discomfort (P = 0.04) and the pain thresholds (P = 0.007) were gradually reduced after the fatty meal, whereas only a tendency in the same direction was seen after the carbohydrate meal. In patients VAS ratings for pain increased after the fatty meal (P = 0.03), but not after carbohydrates. In the controls, sensory thresholds were not affected by the meals. In IBS, a liquid meal enhances rectal sensitivity, and this seems to be partly nutrient dependent as a fatty meal has more pronounced effects than a carbohydrate meal. This might be of relevance for their postprandial symptoms.

Adult↗

PubMed2005

High interdigestive and postprandial motilin levels in patients with the irritable bowel syndrome.

Motilin shows cyclic variation with the different phases of the migrating motor complex (MMC). Altered motilin levels have been found in irritable bowel syndrome (IBS) patients, but in these studies motilin levels were analysed without the knowledge of the phases of MMC. We included 13 healthy controls (HC) and 24 patients with IBS [12 diarrhoea-predominant (IBS-D) and 12 constipation-predominant (IBS-C)]. We performed interdigestive and postprandial antroduodenojejunal manometry and blood samples for analysis of motilin were drawn. Group differences in plasma levels of motilin were analysed during mid-phase II, just before the start of phase III (pre-III), during phase I, immediately before the meal and 30 and 60 min after the 500 kcal mixed meal. Higher motilin levels were observed in IBS vs HC in both the interdigestive and postprandial periods (P < 0.05). No significant differences between IBS-C and IBS-D were observed. The cyclic variation of motilin during MMC and the meal response was similar in IBS and controls. IBS patients, irrespective of the predominant bowel habit, demonstrate higher motilin levels than HCs in all phases of the MMC and also after a meal. These findings may bear some pathophysiological importance in IBS and relate to the gastrointestinal dysmotility often seen in these patients.

Adult↗

PubMed2005

Effects of long-term treatment with oxytocin in chronic constipation; a double blind, placebo-controlled pilot trial.

BACKGROUND: Oxytocin and its receptor have been found throughout the gastrointestinal (GI) tract, where it affects gut function. Clinically, we have noticed an improvement of bowel habits during lactation in constipated women. The aim of this study was to examine whether oxytocin has an effect on bowel symptoms and psychological well being in women with refractory constipation. METHODS: Fifty-nine women with refractory constipation were included in a double blind, multicentre study. After a 2-week run-in period, they were randomly allocated to nasal inhalation of either placebo or oxytocin treatment twice daily for 13 weeks, followed by a 2 weeks, posttreatment period. The patients completed a questionnaire every day concerning bowel habits, abdominal pain and discomfort, and Gastrointestinal Symptoms Rating Scale (GSRS) and Psychological General Well-being (PGWB) twice during the study; namely, during the baseline period and at the end of the treatment period. RESULTS: Both oxytocin and placebo led to improvement of the constipation according to the GSRS and led to improvement in the sensation of incomplete evacuation and anorectal obstruction, without significant differences between the groups. Abdominal pain and discomfort responded weakly to oxytocin, with no effect of the placebo. In a subgroup of patients with IBS and concomitant depression, a weak improvement in depressed mood was observed after oxytocin administartion. CONCLUSION: Nasal administration of oxytocin had no significant advantage over placebo concerning an effect on constipation. However, it seems to have a positive effect on abdominal pain and discomfort and depressed mood. These findings should be further explored.

Adult↗

PubMed2004

Delay in gastric emptying in patients with chronic renal failure.

BACKGROUND: Gastrointestinal (GI) symptoms are common in patients with chronic renal failure (CRF). Delayed gastric emptying might be a possible pathophysiological mechanism. The aims of this study were to evaluate gastric emptying in patients with CRF and to correlate the findings with GI symptoms and evaluate the impact of Helicobacter pylori infection in CRF patients on gastric emptying. METHODS: Thirty-nine patients with CRF (17 F, 22 M) were compared with 131 healthy subjects (74 F, 57 M). A standardized breakfast was given with 20 spherical, radiopaque markers (ROMs). The emptying was followed by fluoroscopy after 4, 5 and 6 h. Gastric emptying was assessed by calculating the individual mean percentual gastric retention of markers, 4 to 6 h after the meal. The perceived severity of GI symptoms was assessed with a validated questionnaire. Because of gender differences in gastric emptying, men and women were compared separately and a percentile of 95 was chosen as the upper reference value. H. pylori infection was assessed using a serological method. RESULTS: Delayed gastric emptying was found in 14 out of 39 (36%) of the CRF patients. There was no relationship between delayed gastric emptying and age, GI symptoms, H. pylori infection or underlying renal disease. However, a higher proportion of patients in peritoneal dialysis demonstrated delayed gastric emptying compared with predialytic patients (6 of 9 versus 2 of 13, P = 0.026). Men with CRF had a higher gastric retention compared with healthy men (16.6 (0-63.3)% versus 0 (0-2.1)%, P < 0.0001), and 10 men with CRF had delayed gastric emptying (P < 0.0001). There was no significant difference in mean gastric retention between women with CRF and healthy women (13.3 (0-55.4)% versus 10.8 (0-30.0)%, P = 0.93), but 4 women with CRF had delayed gastric emptying (P = 0.02). Eighteen of the CRF patients had GI symptoms (6 F, 12 M) and 21 were asymptomatic (11 F, 10 M). There was no difference in mean gastric retention in patients with CRF with and without GI symptoms (M: 13.3 (0-55.0)% versus 47.5 (5.0-65.0)%, P = 0.51, F: 16.6 (0-63.3)% versus 13.3 (0-59.2)%, P = 0.96). Gastric emptying in CRF patients with and without H. pylori infection showed no difference. CONCLUSIONS: Delayed gastric emptying is common in patients with chronic renal failure, particularly in men. The delay was not associated with the presence of GI symptoms, underlying renal disease or H. pylori infection. However, the dialytic status might have an impact on gastric emptying in patients with CRF.

Adult↗

PubMed2004

Oxytocin stimulates colonic motor activity in healthy women.

The effects of oxytocin in the gastrointestinal tract are unclear. The aim of this study was to examine the effect of infusion of oxytocin on colonic motility and sensitivity in healthy women. Fourteen healthy women were investigated twice. A 6-channel perfusion catheter, with three recording points (2 cm apart) proximally and three recording points distally to a barostat balloon, was inserted to the splenic flexure. An intestinal feeding tube was placed in the mid-duodenum. A 90-min duodenal lipid infusion of 3 kcal min(-1) was administered. Thirty minutes after the start of the lipid infusion, the subject randomly received either 20 or 40 mU min(-1) of oxytocin, or isotonic saline as intravenous infusions for 90 min. Meanwhile, the colonic motility was recorded. During the last 30 min of oxytocin and saline infusion, the visceral sensitivity to balloon distensions was examined. During lipid infusion the number of antegrade contractions per hour was 0.7 +/- 0.3 after saline and 3.9 +/- 1.4 after oxytocin (P = 0.03), indicating more pronounced lumen-occlusive contractile activity after oxytocin administration. Some of these consisted of high-amplitude (> 103 mmHg in amplitude) antegrade contractions. Lipid infusion evoked a decrease of the balloon volume, reflecting increased colonic tone, but there was no difference between saline and oxytocin. Sensory thresholds did not differ significantly between saline and oxytocin. Infusion of oxytocin stimulates antegrade peristaltic contractions in stimulated colon in healthy women. The effects of oxytocin on colonic motor activity deserve to be further explored, especially in patients with colonic peristaltic dysfunction.

Adult↗

PubMed2004

Altered visceral perceptual and neuroendocrine response in patients with irritable bowel syndrome during mental stress.

BACKGROUND AND AIMS: Stress often worsens the symptoms of irritable bowel syndrome (IBS). We hypothesised that this might be explained by altered neuroendocrine and visceral sensory responses to stress in IBS patients. SUBJECTS AND METHODS: Eighteen IBS patients and 22 control subjects were assessed using rectal balloon distensions before, during, and after mental stress. Ten controls and nine patients were studied in supplementary sessions. Rectal sensitivity (thresholds and intensity-visual analogue scale (VAS)) and perceived stress and arousal (VAS) were determined. Plasma levels of corticotropin releasing factor (CRF), adrenocorticotropic hormone (ACTH), cortisol, noradrenaline, and adrenaline were analysed at baseline, immediately after stress, and after the last distension. Heart rate was recorded continuously. RESULTS: Thresholds were increased during stress in control subjects (p<0.01) but not in IBS patients. Both groups showed lower thresholds after stress (p<0.05). Repeated distensions without stress did not affect thresholds. Both groups showed increased heart rate (p<0.001) and VAS ratings for stress and arousal (p<0.05) during stress. Patients demonstrated higher ratings for stress but lower for arousal than controls. Basal CRF levels were lower in patients (p<0.05) and increased significantly during stress in patients (p<0.01) but not in controls. Patients also responded with higher levels of ACTH during stress (p<0.05) and had higher basal levels of noradrenaline than controls (p<0.01). Controls, but not patients, showed increased levels of adrenaline and noradrenaline in response to stress (p<0.05). CONCLUSIONS: Stress induced exaggeration of the neuroendocrine response and visceral perceptual alterations during and after stress may explain some of the stress related gastrointestinal symptoms in IBS.

Adrenocorticotropic Hormone↗

PubMed2003

Lipid-induced colonic hypersensitivity in irritable bowel syndrome: the role of 5-HT3 receptors.

BACKGROUND: Irritable bowel syndrome patients demonstrate colonic hypersensitivity after duodenal lipid infusion. AIM: To investigate the role of 5-hydroxytryptamine-3 (5-HT3) receptors in this sensory component of the gastrocolonic response in irritable bowel syndrome. METHODS: Fifteen female patients with diarrhoea-predominant irritable bowel syndrome completed a trial with the 5-HT3 receptor antagonist alosetron (1 mg b.d.) or placebo (b.d.) over 15 days, followed by the alternative treatment. Each treatment period was followed by a colonic distension trial before and after duodenal lipids. Changes in colonic thresholds, tone and compliance and viscerosomatic referral pattern after lipids were compared between treatments. RESULTS: With placebo, the colonic thresholds after lipids were significantly reduced for all studied sensations, whereas, with alosetron, the thresholds were significantly reduced only for first sensation and discomfort, but not for gas and pain. The reductions in thresholds did not differ significantly between treatments, but the pain threshold after alosetron tended to be less reduced compared with placebo (P = 0.10). The effects of lipids on tone, compliance and viscerosomatic referral pattern were unaffected by alosetron relative to placebo. CONCLUSIONS: 5-HT3 receptor antagonism reduces the lipid-induced colonic hypersensitivity in irritable bowel syndrome. However, 5-HT3 receptors do not seem to be the principal mediator, but may be a cofactor for the exaggerated sensory component of the gastrocolonic response in irritable bowel syndrome.

Adult↗

PubMed2001

Impact of sex and psychological factors on the water loading test in functional dyspepsia.

BACKGROUND: The pathogenesis of upper abdominal symptoms in patients with functional dyspepsia (FD) is still unclear. The water loading test (WLT) is a new method for evaluation of gastric function. Our aim was to determine the impact of sex, age and psychological factors on the results of WLT in FD patients, FD-subgroups and healthy controls (HCs), and to evaluate the safety of the test. METHODS: Fifty-six HCs and 35 consecutive patients with FD drank mineral water (100 ml/min) until intolerable. Serum samples for sodium, potassium and creatinine was taken before and after drinking. Water quantity was registered and symptoms were assessed after maximal water intake and 30 min later using a VAS scale. Participants also completed questionnaires measuring psychological general well-being (PGWB) and gastrointestinal symptoms (GSRS and Mearin score). RESULTS: Healthy men drank more than healthy women, 2350 +/- 105 ml versus 1860 +/- 100 ml (P < 0.01), and the same gender difference was noted in FD patients, 1770 +/- 115 ml versus 1180 +/- 110 ml (P < 0.01). Maximal water intake was significantly higher in HC than in FD patients, both in males (P < 0.001) and females (P < 0.0001). Age had no impact on drinking capacity. FD patients had more symptoms 30 min after maximal water intake than HCs. Serum sodium decreased from 141 +/- 0.3 mmol/l to 138 +/- 0.5 mmol/l. Two of the assessed psychological factors, general health and depressed mood, correlated with water intake in FD patients (Rho = 0.47, P < 0.01 respectively Rho = 0.41, P < 0.05). CONCLUSION: WLT is a useful, simple and safe test for evaluating symptoms in FD patients. Sex, but not age affects the results of the WLT. Furthermore, psychological factors must also be taken into consideration when interpreting the WLT.

Adult↗

PubMed2001

Quality of life in patients with irritable bowel syndrome seen in referral centers versus primary care: the impact of gender and predominant bowel pattern.

BACKGROUND: Quality of life (QOL) is reduced in patients with irritable bowel syndrome (IBS) and little is known about differences in QOL in relation to referral status, gender and predominant bowel pattern in IBS patients. This study aimed to explore these relationships. METHODS: 343 patients with IBS according to the Rome I criteria (251 females, 92 males) completed five different self-administered questionnaires to evaluate QOL. There were 119 patients with diarrhea-predominant IBS (IBS-D), 93 with constipation-predominant IBS (IBS-C) and 131 with alternating constipation and diarrhea (IBS-A). The study group comprised 209 hospital outpatients and 134 primary care patients. The questionnaires were mailed to the patients with an overall response rate of 88%. RESULTS: QOL was reduced in hospital outpatients compared to primary care patients, but only in females. IBS subgroup (IBS-D), physical fatigue and general health independently predicted referral to a gastroenterologist. Females had lower QOL than males. No differences, except in severity of diarrhea and constipation, were observed between IBS subgroups. Perceived fatigue was related to well-being, psychological and gastrointestinal symptoms. Independent predictors for fatigue were depression, trait anxiety, general health and vitality, along with eating dysfunction and female sex. CONCLUSION: IBS female patients seen in referral centers versus primary care is a highly selected group with reduced QOL. QOL in IBS is affected by gender, but not by subgroup. Our findings have implications for the generalizability of results in IBS trials. Fatigue is a common symptom in IBS that correlates to general well-being and psychological and subjective gastrointestinal symptoms.

Adolescent↗

PubMed2001

An exaggerated sensory component of the gastrocolonic response in patients with irritable bowel syndrome.

BACKGROUND/AIMS: Visceral hypersensitivity is a feature of the irritable bowel syndrome (IBS). Postprandial symptoms are common in these patients. The effects of nutrients on colonic perception in IBS are incompletely understood. SUBJECTS: We studied 13 healthy subjects and 16 patients with IBS-eight had diarrhoea predominant (IBS-D) and eight constipation predominant (IBS-C) IBS. METHODS: Colonic perception thresholds to balloon distension and viscerosomatic referral pattern were assessed before and after duodenal infusion of lipid or saline, respectively. At the end of the infusions, plasma levels of gastrointestinal peptides were determined. RESULTS: Lipids lowered the thresholds for first sensation, gas, discomfort, and pain in the IBS group but only for gas in the control group. The percent reduction in thresholds for gas and pain after lipids was greater in the IBS and IBS-D groups but not in the IBS-C group compared with controls. IBS patients had an increased area of referred discomfort and pain after lipids compared with before infusion whereas the referral area remained unchanged in controls. No group differences in colonic tone or compliance were observed. In both groups higher levels of cholecystokinin, pancreatic polypeptide, peptide YY, vasoactive intestinal polypeptide, and neuropeptide Y were seen after lipids. Motilin levels were higher in patients and differences in the subgroups were observed. Levels of corticotrophin releasing factor were lower in the constipated group than in the diarrhoea group. CONCLUSIONS: Postprandial symptoms in IBS patients may be explained in part by a nutrient dependent exaggerated sensory component of the gastrocolonic response.

Adult↗

PubMed2001

Food-related gastrointestinal symptoms in the irritable bowel syndrome.

BACKGROUND/AIMS: Postprandial symptoms are common in patients with irritable bowel syndrome (IBS). However, existing studies have come to different conclusions about the role of food in the pathophysiology of IBS. We explored the prevalence of subjective food-related gastrointestinal (GI) symptoms and its relationship to clinical characteristics and psychological factors in IBS. METHODS: 330 patients with IBS and 80 healthy volunteers completed a food questionnaire developed for this study. The subjects graded their subjective symptoms after 35 different foods and a food score was obtained by adding the item scores. The relationship between subjective food-related GI symptoms and referral status, IBS subgroup (predominant bowel pattern), sex, anxiety, depression and body mass index (BMI) was estimated. RESULTS: In 209 (63%) of the patients the GI symptoms were related to meals. Gas problems and abdominal pain were the most frequently reported symptoms. Foods rich in carbohydrates, as well as fatty food, coffee, alcohol and hot spices were most frequently reported to cause symptoms. The food score was higher in patients than in controls (p < 0.0001). In the IBS group higher scores were observed in patients with anxiety (p = 0.005), and females (p < 0.001), but the results were unrelated to IBS subgroup, referral status or BMI. The BMI did not differ between groups. CONCLUSION: A majority of IBS patients consider their symptoms to be related to meals. Especially foods rich in carbohydrates and fat cause problems. Nevertheless, the majority of IBS patients are normal or overweight. Female sex and anxiety predict a high degree of food-related symptoms in IBS.

Adult↗

PubMed1999

Contractile patterns in patients with severe chronic dyspepsia.

OBJECTIVE: Antroduodenojejunal interdigestive and postprandial pressure recordings were analyzed in 41 consecutive patients referred for evaluation of severe chronic dyspepsia. In addition to traditional manometric evaluation we also focused on the propagation pattern of individual pressure waves in the proximal duodenum. METHODS: Catheters with closely spaced side holes for temporospatial analysis of the computerized recordings were used. The dominating symptoms were unexplained nausea and vomiting (n = 18), chronic abdominal pain (n = 16), or both (n = 7). The patients' mean age was 45 yr (31 women and 10 men). Gastric surgery had been performed on 11 patients. Results from 20 healthy volunteers served as a reference range. RESULTS: Findings were suggestive of neuropathy in 16 (39%) and myopathy in 1 (2.4%) using conventional criteria. Another 19 patients of the 24 with normal condensed recordings showed abnormalities in the propagation pattern of individual pressure waves in phase II and/or during the fed state, when compared with the controls. Absence of phase III of the migrating motor complex was found in 12 patients during the 5-h fasting recording, compared with none in the controls (p < 0.01). Retroperistalsis at the end of phase III in the duodenum was present in at least one of the activity fronts in all patients having migrating motor complex except one, which was similar to the controls. During phase II, unpropagated bursts of phasic and tonic activity were more frequent in patients than in controls (mean 13.2% vs 3.7% of the time; p < 0.05), and a higher proportion of individual contractions was retrograde in patients than in controls (17.4% vs 5% of propagated contractions; p < 0.05). Patients had higher postprandial motility index in the distal duodenum than did controls (p < 0.05). Moreover, after feeding more individual contractions were retrograde in patients than in controls (33.1% vs 10% of propagated contractions; p < 0.01). Sequences of localized supratachyarrythmia, 25-35/min in the antrum and 50-60/min in the small bowel associated with symptoms, were observed in two patients. CONCLUSION: Manometry is important for demonstration of pathophysiology in patients with unexplained abdominal pain, nausea, and vomiting. Simultaneous analysis of the propagation of individual contractions of interdigestive and fed motility is superior to conventional manometry alone.

Adolescent↗

PubMed1998

Differential 5-HT3 mediation of human gastrocolonic response and colonic peristaltic reflex.

Colonic motor function is modulated by extended and local neural reflexes involving unknown mediators. To test the role of serotonin (5-HT3) pathways, increases in colonic tone during antral distension and duodenal lipid perfusion (gastrocolonic responses) and changes in orad and caudad colonic tone in response to local colonic distension (peristaltic reflex) were measured after double-blind granisetron (10 microg/kg) or placebo infusion in healthy human volunteers. Antral distension evoked increases in colonic tone, which were blunted by granisetron (P < 0.05) without effects on antral compliance. Intraduodenal lipid perfusion also evoked increased colonic tone, which was reduced by granisetron (P < 0.05). In contrast, orad colonic contractions and caudad relaxations and contractions during colonic distension were unaffected by granisetron. In conclusion, 5-HT3 receptor antagonism blunts both the mechano- and chemoreceptor components of the human gastrocolonic response without altering antral compliance. In contrast, 5-HT3 pathways play no role in the ascending or descending components of the colonic peristaltic reflex. These findings demonstrate different roles for 5-HT3 receptors in the control of colonic motor function by the proximal gastrointestinal tract and by local neural reflexes.

Adult↗

PubMed1997

Nocturnal antral pH rises are related to duodenal phase III retroperistalsis.

The mechanisms behind nocturnal rises of gastric pH are unknown. We have analyzed the relation between interdigestive duodenal peristalsis and nocturnal pH in the gastric antrum. Simultaneous recording of antroduodenal pressures and intragastric pH was performed in 11 healthy subjects (six men, five women) overnight for 8 hr, using a catheter with seven pressure recording points and an antral glass pH electrode. Three pressure recording sites were closely spaced in the descending duodenum. Altogether 46 phase III activities were recorded. A retroperistaltic sequence in the last part of phase III was observed in 31 phase III activities (67.4%), while 15 phase III activities lacked retroperistalsis. All subjects had retroperistalsis in at least one phase III at night with a median of 60% (52-100%) (interquartile range). The duration of the whole phase III was 5.1 (3.1-7.0) min, whereas the duration of the retroperistaltic period was 2.0 (1.5-3.2) min, corresponding to 45% (23-64%) of the duration of phase III. The peak of antral pH occurred 7.4 (6.0-13.0) min from the start of the phase III in the duodenum and and the rise in pH lasted for 8.0 (4.8-12.0) min. Measurement of pH for a period of 10 min before and after phase III, demonstrated an increase in median pH from 1.2 (1.1-1.9) to 3.2 (1.6-4.7), respectively (P < 0.001). Phase III activities without duodenal retroperistalsis were not followed by a significant antral pH change (median 1.7 vs 1.8 before and after phase III, respectively). Increases of pH unrelated to phase III were uncommon, only 1.0 (1.0-2.2) events per night were observed and lasted for a short period of time, 2.1 (0.5-3.2) min. The results indicate that the cyclic rise in antral pH at night is due to a physiological duodenogastric reflux, caused by duodenal retroperistalsis in phase III. This reflux may play a role in protection of the antral mucosa.

Adult↗

PubMed1996

Interdigestive and postprandial motility in small-intestinal bacterial overgrowth.

BACKGROUND: Motility disorders are believed to be of major pathogenetic importance in small-intestinal bacterial overgrowth (SIBO). The aim of this study was to investigate interdigestive and postprandial motility in a group of patients with SIBO and to compare the results with those of healthy volunteers. METHODS: Twenty healthy subjects and 14 patients with SIBO were included. Exclusion criteria were obvious predisposing conditions. Antroduodenojejunal pressure recording was performed after an overnight fast. After a 5-h interdigestive recording a standard meal was given, and postprandial recording performed for 30 min. RESULTS: Significantly fewer patients than healthy subjects had phase-III activity in the antrum (3 of 14 versus 15 of 20; P < 0.01), and more patients lacked phase III completely (5 of 14 versus 0 of 20; P < 0.05). Propagated single contractions in the proximal duodenum during late phase II and postprandially were also significantly reduced (1 (0-5) versus 8 (5-12) per 30 min (median; interquartile range (IQR)) (P < 0.01) and 0.5 (IQR, 0-6.5) versus 8 (IQR, 6-13) per 30 min (P < 0.01), respectively). In the distal part of the duodenum the patients had significantly prolonged duration of phase III (7.8; IQR, 5.6-9.2 versus 5.9; IQR, 4.2-6.6 min) (P < 0.05) and increased motility index of phase III (6685; IQR, 4870-9999 versus 3605; IQR, 2579-5544 mm Hg x min/30 min) (P < 0.05), late phase II (10,285; IQR, 6105-11,384 versus 6650; IQR, 4639-9102) (P < 0.05), and postprandially (12,960; IQR, 8454-18,644 versus 7917; IQR, 6132-10,551) (P < 0.05). Retrograde contractions predominated in the late part of phase III in the proximal duodenum in both groups. The cycle length of the MMC and the number of clustered contractions showed no difference between the two groups. CONCLUSIONS: A significant proportion of patients with SIBO, compared with healthy subjects, lack interdigestive phase-III activity, not only in the small intestine but also in the gastric antrum. They also have fewer propagated contractions in the proximal duodenum during interdigestive phase II. On the other hand, the motility index in the distal part of the duodenum was higher in patients with SIBO during phase III, late phase II, and postprandially. The results are compatible with a reduced clearing function in the stomach and proximal duodenum and/or a compensatory increase of motility in the region of the duodenojejunal flexure.

Adult↗

PubMed1995

Interdigestive gastroduodenal manometry in humans. Indication of duodenal phase III as a retroperistaltic pump.

To elucidate the specific function of the three phases (I-III) of the migrating motor complex (MMC) by manometry, detailed analysis of individual pressure waves in the proximal duodenum was performed. Twenty healthy subjects (10 men and 10 women of whom 11 were tube-naive) underwent computerized manometry for 5 h during fasting followed by 45 min after a meal using an 8-channel water perfused catheter. Three recording points were in the antrum, three in the proximal duodenum (2 cm apart), one in the distal duodenum and one in the proximal jejunum. In all subjects at least one phase III (median 2) was observed during the 5-h fasting recording. In the proximal duodenum the mean proportion of retrograde pressure waves, out of all propagating waves, was significantly increased in the last part of phase III (85 +/- 9%, mean, SE), compared with early phase III (6 +/- 5%), late phase II (5 +/- 4%) and the feeding phase (10 +/- 5%), irrespective of gender or previous tube-experience. The median length of the MMCs was 108.5 min. There was no statistically significant difference between men and women or between tube-naive and tube-experienced subjects for the duodeno-jejunal motility indices of phase II and phase III, nor for duration or migration of phase III. The postprandial motility index of the small intestine was increased compared with the interdigestive late phase II, particularly in the jejunum (P < 0.02). The last part of the duodenal interdigestive phase III in healthy subjects shows the feature of a retrosperistaltic pump. This cyclic sequence of retropropagation coincides with the reported rapid alkalinization of the duodenal bulb and the gastric antrum occurring in early antral phase I.

Adult↗

PubMed1995

Comparison between physiologic and erythromycin-induced interdigestive motility.

BACKGROUND: The last part of duodenal phase III of the migrating motor complex behaves as a retroperistaltic pump. We have compared the phase-III-like gastroduodenojejunal activity induced by erythromycin with the naturally occurring phase III, focusing on peristaltic patterns. The effect of two doses of erythromycin, 3 mg/kg/h and 12 mg/kg/h (in four subjects), or saline, given intravenously for 15 min, was studied in nine fasting healthy subjects (five men and four women). METHODS: Motility was recorded on three different days. On one day standard 5-h eight-channel antroduodenojejunal manometry was performed and saline infused 30 min after the first phase III. On the other two study days, erythromycin in the low or the high dose was infused and recording performed for another 2-h period. RESULTS: The low dose of erythromycin induced a phase III in the stomach in all subjects within 12.8 +/- 1.4 min. In contrast, the higher dose did not induce phase-III activity within the 1st h after infusion but induced marked antral pressure waves. The duration of the erythromycin-induced phase III and the naturally occurring antral phase III was 4.7 +/- 1.7 and 1.9 +/- 0.3 min, respectively (p < 0.01). The duration of the erythromycin-induced phase III in the proximal jejunum was 44% shorter than the spontaneous one (p < 0.01). The propagation velocity, from the proximal duodenum to the proximal jejunum, of the erythromycin-induced phase III was slower than that of the spontaneous phase III: 5.7 +/- 0.9 and 15.9 +/- 3.9 cm/min, respectively (p < 0.01). In the proximal duodenum the proportion of retrograde pressure waves (of all propagating waves) was about 10% in early phase III, increasing to about 85% in late phase III in both the spontaneous and erythromycin-induced phase III. In the proximal jejunum retrograde pressure waves were not observed in phase III. CONCLUSIONS: Erythromycin given in a low dose is very effective in inducing phase-III-like motility. The last part of duodenal phase III is characterized by retroperistalsis also when this motility phase is induced by erythromycin.

Adult↗

PubMed1995

Effects of insulin and beta-adrenergic blockade on the migrating motor complex in humans.

BACKGROUND: Interdigestive small-intestinal motility is suppressed by hyperglycemia and also by hyperinsulinemia per se. Since hyperinsulinemia may increase sympathetic activity, the present study was undertaken to ascertain to what extent insulin affects phase III of the migrating motor complex (MMC) and MMC-related duodenal retroperistalsis and whether beta-adrenergic receptors may mediate the effects of insulin. METHODS: Fasting motility was studied in eight healthy volunteers on three occasions with an eight-lumen perfused pressure catheter, with closely spaced recording points in the proximal duodenum. On the control day 5-h antroduodenojejunal manometry was performed. On another study day euglycemic hyperinsulinemic clamping was performed for 2 h after an initial basal recording. On a 3rd day motility was recorded during propranolol infusion, combined with a period of euglycemic hyperinsulinemia. RESULTS: During hyperinsulinemia complete absence of phase III of the MMC in the gastric antrum was observed, whereas 55% of the MMC had a gastric phase-III component on the control day. The duration of phase III in the proximal duodenum was decreased during hyperinsulinemia compared with the control period (p < 0.05). This inhibitory effect of insulin on the activity front was not prevented by beta blockade. Under control conditions the proportion of retroperistaltic pressure waves in the proximal duodenum was 13 +/- 8% in early phase III, increasing in late phase III to 79 +/- 15% (p < 0.01). Duodenal phase III during hyperinsulinemia showed a similar increase in retroperistalsis, from 4 +/- 4% in early phase III to 67 +/- 21% in late phase III (p < 0.01). The corresponding proportions during beta blockade were 16 +/- 10% and 86 +/- 14%, respectively. CONCLUSIONS: Hyperinsulinemia per se abolishes antral phase III and makes the duodenal phase III shorter but does not interrupt the distinct pattern of retroperistalsis in late phase III. Beta-adrenergic receptors seem not to be important for these effects of insulin or for the retroperistalsis in duodenal phase III.

Adult↗