5—羟色胺再摄取抑制对小肠传递影响的研究

目的探讨选择性５羟色胺再摄取抑制剂对小肠传递功能的影响。方法８名健康志愿者连续５天口服帕罗西丁，２０ｍｇ／天，于用药前一天和停药次日进行乳果糖氢呼气试验测定口－盲肠通过时间。结果口－盲肠通过时间从用药前８６±２３分钟降至用药后的６８±２０分钟，差异显著（ｔ＝３．４３９，Ｐ＜０．０５）。结论５羟色胺参与胃肠道动力调节，选择性５羟色胺再摄取抑制剂具有促小肠动力作用。     

Effect of intestinal resection on human small bowel motility.

BACKGROUND: Few data are available on adaptive changes of human small bowel motility after intestinal resection. AIM: To characterise jejunal motility after extensive and limited distal intestinal resection. METHODS: Seven patients with a short bowel syndrome after total ileal and partial jejunal resection (residual jejunal segments between 60 and 100 cm) and six patients with limited distal ileal resection (resected segment between 30 and 70 cm) underwent ambulatory 24 hour jejunal manometry 15 (6-24) months after the operation. Normal values were obtained from 50 healthy subjects. Fasting motility and the motor response to a 600 kcal solid meal were analysed visually and by a computer program. RESULTS: Limited ileal resection did not result in changed jejunal motility. After extensive distal resection, patients had a significantly shorter migrating motor complex (MMC) cycle and a significantly shorter duration of the postprandial motor response compared with controls (p < 0.005). Intestinal resection had no influence on jejunal contraction frequency and amplitude and did not lead to any abnormal motor pattern. CONCLUSION: Extensive distal resection of the small intestine produces distinct abnormalities of fasting and postprandial motility in the intestinal remnant. The shortening of digestive motility and the increased frequency of MMC cycling could contribute to malabsorption and diarrhoea in the short bowel syndrome.     

Roles of gall bladder emptying and intestinal transit in the pathogenesis of octreotide induced gall bladder stones.

BACKGROUND--Octreotide treatment of acromegalic patients increases the % deoxycholic acid conjugates and the cholesterol saturation of gall bladder bile, and induces gall stone formation. AIMS--To study the roles of gall bladder emptying and intestinal transit in these phenomena. METHODS AND PATIENTS--Gall bladder emptying and mouth to caecum transit was measured in (a) control subjects and acromegalic patients given saline or 50 micrograms of octreotide, and (b) acromegalic patients taking long term octreotide. In the second group, large bowel transit was also measured. RESULTS--A single dose of octreotide inhibited meal stimulated gall bladder emptying, the ejection fraction falling from mean (SEM) 66.0 (2.3)% to 7.0 (5.3)% in controls (p < 0.001); from 72.5 (2.1) to 16.6 (5.1)% in untreated acromegalic patients (p < 0.001), and to 30.4 (9.5)% in acromegalic patients taking long term octreotide (p < 0.001 v untreated acromegalic group). Octreotide prolonged mouth to caecum transit time, from 112 (15) min to 237 (13) min in controls (p < 0.001), from 170 (13) min to 282 (11) min in untreated acromegalic patients (p < 0.001), and to 247 (10) min in acromegalic patients taking long term octreotide (p < 0.001 v untreated acromegalic patients). The mean large bowel transit in octreotide untreated compared with treated acromegalic patients remained unchanged (40 (6) h v 47 (6) h). CONCLUSIONS--Prolongation of intestinal transit and impaired gall bladder emptying may contribute to lithogenic changes in bile composition and gall stone formation in patients receiving long term octreotide.     

Effect of a tricyclic antidepressant on small intestinal motility in health and diarrhea-predominant irritable bowel syndrome

Antidepressants are used in irritable bowel syndrome (IBS) and may have effects on the gut independent of improving mood. We have investigated the actions of a tricyclic antidepressant on small intestinal motor function in eight healthy volunteers and in six patients with diarrhea-predominant IBS. Fasting ambulatory motility was recorded from six small intestinal sites for 16–18 hr while on no drug (baseline) and while taking imipramine for five days. Orocecal transit time (OCTT) was measured by lactulose hydrogen breath test, during baseline and imipramine administration. Imipramine did not alter migrating motor complex periodicity, but slowed jejunal phase III propagation velocity in controls from 7.5±1.1 to 3.6±0.5 cm/min (P<0.01) and in IBS from 7.8±0.6 to 4.4±0.5 cm/min (P<0.0001). Phase III duration at each site was increased, and total recorded phase III was greater during imipramine than baseline studies. Imipramine increased the amplitude of phase III contractions. There was no effect of imipramine on non-phase-III motility index or discrete clustered contractions. Imipramine prolonged OCTT from 73±6 min to 97±8 min in controls (P<0.05) and from 61±9 min to 89±8 min in IBS (P<0.05). Although OCTT was shorter in this IBS group, no motility differences were seen between controls and IBS. This demonstration that a tricyclic antidepressant can modify small intestinal motor function in health and in IBS supports the view that these drugs may have therapeutic actions in IBS unrelated to mood improvement.This work was supported by the Priory Hospitals Group.     

Effect of the quaternary ammonium compound trospium chloride on 24 hour jejunal motility in healthy subjects.

This study aimed to record 24 hour jejunal motility in healthy ambulant subjects and to analyse changes in motility caused by the oral administration of an anticholinergic agent, the quaternary ammonium compound, trospium chloride. In a placebo-controlled, double blind crossover trial, 24 hour jejunal motility was recorded in 12 healthy volunteers, aged 25 (21-30) years, using a digital data logger connected to two strain-gauge transducers mounted 20 cm apart in a flexible nasojejunal catheter. A computer program was developed to determine contraction parameters. Trospium chloride (15 mg orally thrice daily) prolonged the duration of irregular contractile activity after meals (p < 0.02) and reduced its contraction frequency and amplitude (p < 0.001). In the fasting state, the cycle length of the migrating motor complex was prolonged (p < 0.01) by an extended phase I (p < 0.025). Phase III was shortened (p < 0.005) and showed a slower aboral migration velocity (p < 0.005). Clustered contractions were less frequent during postprandial and fasting periods (p < 0.01). Runs of clustered contractions were completely absent with trospium chloride. Digital manometry was useful for long term recordings of jejunal motility and enabled the motor effects of an anticholinergic agent to be characterised in ambulant subjects.     

Stimulation of beta-adrenoceptors with isoprenaline inhibits small intestinal activity fronts and induces a postprandial-like motility pattern in humans.

AIMS: To investigate the effects of beta-adrenoceptor stimulation, using the agonist isoprenaline and the antagonist propranolol, on migrating motor complexes in the upper intestine of 16 healthy human volunteers. METHODS: Fasting motility was monitored using a tube with water perfused side holes connected to a pneumohydraulic system. Continuous eight hour recordings were obtained from each volunteer after a 12 hour fasting period. In all experiments, saline was given as control for the first four hour period and beta-adrenergic agents for the next four hours. In separate control studies, saline was given for the whole eight hour period. RESULTS: Isoprenaline (2.5 micrograms/kg/min) reduced the number of activity fronts (phase III) of migrating motor complexes from 3 (2-4) in controls to 1 (0-2) during isoprenaline infusion (p < 0.01). Also, phase II-like activity replaced the regular motility pattern (p < 0.01). By contrast, propranolol (25 micrograms/kg/min) did not induce any significant changes in phase III compared with controls. Saline alone had no effect on motor activity. CONCLUSIONS: Isoprenaline inhibited activity fronts in the human proximal small intestine and induced a postprandial-like motility pattern, whereas propranolol did not affect motor patterns. Stimulation of beta-adrenoceptors is of importance in the control of motor activity of the human small intestine, especially under stressful conditions with high adrenergic activity.     

Small intestinal motor abnormalities in patients with functional dyspepsia demonstrated by ambulatory manometry.

AIMS/METHODS--In 30 patients with functional dyspepsia and in 20 healthy volunteers, ambulatory duodenojejunal manometry was performed to examine the interdigestive and postprandial small intestinal motility patterns in relation to symptoms. RESULTS--In the fasting state, the number of migrating motor complex cycles mean (SEM) was significantly lower in patients, especially in patients with dysmotility-like dyspepsia, than in control subjects (3.8 (0.4), 2.6 (0.5), and 5.3 (0.7) cycles, respectively; p < 0.05), due to a longer duration of phase II. Non-propagated and retrogradely propagated phase III activity was more prevalent in patients than in control subjects (48% v 15%; p = 0.020). During phase II and after dinner no differences were found in contraction incidence, mean amplitude or motility index. However, 1 1/2 hours after completing breakfast the motility index was higher in patients at all three recording levels (p < 0.05). Burst activity was more prevalent in patients than in control subjects (22% v 6% of the subjects; p = 0.003). In 41% of the patients the symptom index was > 75%. CONCLUSIONS--These results suggest that small intestinal motor abnormalities, especially during fasting, participate in the pathogenesis of symptoms in patients with functional dyspepsia. Ambulatory manometry of the small intestine is a valuable tool to demonstrate these abnormalities in outpatients pursuing their daily activities.     

Ambulatory small intestinal motility in 'diarrhoea' predominant irritable bowel syndrome.

Dysmotility of the duodenum and proximal jejunum has been reported in patients with irritable bowel syndrome. This study extended these findings by recording fasting ambulatory motility from electronic strain gauge sensors sited in the jejunum and ileum of eight diarrhoea predominant irritable bowel syndrome patients and 12 healthy controls. During the day, periodicity of migrating motor complexes mean (SEM) did not differ between patients (92 (10) min) and controls (85 (7) min). At night, periodicity was shorter in both patients and controls, and the daytime dominance of phase II was replaced by phase I. In both groups, aboral progression of phase III fronts was associated with a slowing of propagation velocity and maximum contractile rate, but an increase in mean amplitude of contraction. Discrete clustered contractions were seen in seven patients and 10 controls occupying 14 and 16% of daytime phase II activity, respectively. Pain episodes were not associated with any specific motility patterns. Despite the lack of motility differences between the two groups, orocaecal transit time in the irritable bowel syndrome patients was shorter at 57 (9) min than in the controls, 82 (6) min (p < 0.05). This ambulant study has failed to show any abnormalities of fasting small intestinal motility that might distinguish diarrhoea predominant irritable bowel syndrome patients from healthy controls.     

Gastrointestinal function in chronic radiation enteritis--effects of loperamide-N-oxide.

The effects of loperamide-N-oxide, a new peripheral opiate agonist precursor, on gastrointestinal function were evaluated in 18 patients with diarrhoea caused by chronic radiation enteritis. Each patient was given, in double-blind randomised order, loperamide-N-oxide (3 mg orally twice daily) and placebo for 14 days, separated by a washout period of 14 days. Gastrointestinal symptoms; absorption of bile acid, vitamin B12, lactose, and fat; gastric emptying; small intestinal and whole gut transit; and intestinal permeability were measured during placebo and loperamide-N-oxide phases. Data were compared with those obtained in 18 normal subjects. In the patients, in addition to an increased frequency of bowel actions (p < 0.001), there was reduced bile acid absorption, (p < 0.001) a higher prevalence of lactose malabsorption (p < 0.05) associated with a reduced dietary intake of dairy products (p < 0.02), and faster small intestinal (p < 0.001) and whole gut transit (p < 0.05) when compared with the normal subjects. There was no significant difference in gastric emptying between the two groups. Treatment with loperamide-N-oxide was associated with a reduced frequency of bowel actions (p < 0.001), slower small intestinal (p < 0.001), and total gut transit (p < 0.01), more rapid gastric emptying (p < 0.01), improved absorption of bile acid (p < 0.01), and increased permeability to 51Cr EDTA (p < 0.01). These observations indicate that: (1) diarrhoea caused by chronic radiation enteritis is associated with more rapid intestinal transit and a high prevalence of bile acid and lactose malabsorption, and (2) loperamide-N-oxide slows small intestinal transit, increases bile acid absorption, and is effective in the treatment of diarrhoea associated with chronic radiation enteritis.     

Differential regional effects of octreotide on human gastrointestinal motor function.

The effects of octreotide on regional motor function in the human gut are unclear. In a randomised, blinded study the effects of octreotide (50 micrograms, subcutaneously, three times daily) and placebo on gastric, small bowel, and colonic transit, and colonic motility and tone were assessed in 12 healthy volunteers whose colon had been cleansed. Octreotide accelerated initial gastric emptying (p = 0.05), inhibited small bowel transit (p < 0.01), and reduced ileocolonic bolus transfers (p < 0.05). Colonic transit was unaltered by octreotide; the postprandial colonic tonic response was inhibited (p < 0.05 v placebo), whereas colonic phasic pressure activity was increased by octreotide (p < 0.05 v placebo). These data support the use of octreotide in diarrhoeal states but not in diseases that cause small bowel stasis and bacterial overgrowth. Simultaneous measurements of colonic transit, tone, and phasic contractility are valid in studying the effects of pharmacological changes and may be applicable to the study of the human colon in health and disease.     

The effect of acute hyperglycaemia on small intestinal motility in normal subjects

Summary The effects of hyperglycaemia on postprandial small intestinal motor activity are unclear. Duodenal and jejunal pressures and duodeno-caecal transit were measured in eight healthy male volunteers during euglycaemia (blood glucose 4–6 mmol/l) and hyperglycaemia (blood glucose 12–15 mmol/l). Duodenal and jejunal pressures were recorded with a manometric assembly during intraduodenal infusion of 100 ml nutrient liquid comprising 14% protein, 31.5% fat and 54.5% carbohydrate together with 15 g lactulose. Duodeno-caecal transit was determined by a breath hydrogen technique. The number of duodenal (p<0.05) and jejunal (p<0.01) pressure waves, excluding phase III episodes was reduced during hyperglycaemia compared to euglycaemia. Hyperglycaemia was associated with earlier onset of phase III activity (30±12 vs 132±20 min; p<0.05). Duodeno-caecal transit was slower during hyperglycaemia when compared to euglycaemia (114±17 vs 49±6 min, p<0.01). We conclude that induced hyperglycaemia has major effects on postprandial small intestinal motility. The reduction in duodenal and jejunal motor activity is likely to explain the retardation of small intestinal transit during hyperglycaemia.Abbreviations TMPD Transmusocal potential difference - MMC migrating myoelectric complex     

Beta adrenergic modulation of human upper intestinal propulsive forces.

beta Adrenoceptor blockade is known to accelerate transit through the small intestine without changing either the number or pattern of intestinal contractions. This study therefore tested the hypothesis that an increase in intraluminal aboral propulsive force may contribute to this transit acceleration. Twenty paired studies were performed, in 10 healthy volunteers, after oral administration of either 100 mg atenolol (a selective beta 1 antagonist) or matched dummy tablets according to a double blind, randomised protocol. The frequency of occurrence of, and the propulsive force exerted by, traction events related to intestinal contractions were measured, using a combined traction force detector and manometry assembly. After atenolol, a consistent increase in the force generated per traction event was noted, both for propagating contractions mean (SEM) (12.0 (1.8) g v control 5.9 (0.07) g; p < 0.05) and for stationary (11.6 (1.4) g v control 7.0 (0.7) g; p < 0.05). In contrast no change in the number of traction events was noted (control v atenolol = 1.6 (0.3) v 1.64 (0.4) per min for propagating and 0.7 (0.1) v 0.85 (0.16) per min for stationary contraction; p > 0.05). beta Adrenoceptor blockade thus increases the propulsive force generated by intestinal contractions, possibly by removing a sympathetic neural inhibition of intestinal tone.     

Infantile chronic idiopathic intestinal pseudo-obstruction: the role of small intestinal manometry as a diagnostic tool and prognostic indicator.

BACKGROUND: Chronic idiopathic intestinal pseudo-obstruction (CIIP) presenting in infancy is a rare but serious condition of heterogeneous aetiology often with an uncertain outcome. AIM: To assess whether intestinal manometry in the first two years of life can help define a neuropathic or myopathic aetiology or clinical outcome, or both, in cases of infantile CIIP. SUBJECTS AND METHODS: 14 consecutive children who presented in the first year of life with CIIP were studied histologically and by small intestinal manometry. RESULTS: Five had a myopathic disorder, four were neuropathic, and five unclassified following histological investigation of full thickness intestinal biopsy specimens. Analysis of fasting phase III activity showed four patterns: (1) (n = 4) no detectable motor activity, (2) (n = 5) low amplitude phase III activity, (3) (n = 3) poorly formed phase III complexes of short duration, (4) (n = 2) well formed cyclical phase III activity with abnormal propagation. The seven children with low amplitude phase III: motility index (MI) < 10 KPa/min, all had a poor outcome (death or dependence on parenteral nutrition) after 1-10 years follow up, compared with two of seven of those with a MI > 10 KPa/min. Of the five with myopathic histology, four had a MI < 10 KPa/min. CONCLUSION: These results show that small intestinal manometry is useful not only as an aid in diagnosing the aetiology of CIIP presenting in infancy, but also in predicting outcome.     

Disturbed gastric emptying in the short bowel syndrome. Evidence for a 'colonic brake'.

Gastric emptying of liquid (orange juice containing technetium-99m (99mTc) labelled antimony sulphide colloid) and solid (570 kcal pancake containing 0.5 mm resin microspheres labelled with Indium-111 (111-In)) was measured in seven patients with jejunum and no colon (jejunal lengths 30-160 cm), six patients with jejunum in continuity with the colon (jejunal length 25-75 cm), and in 12 normal subjects. In patients with no colon early emptying of liquid was rapid (median 25% emptying: 7 v 25 min, no colon v normal, p < 0.05); early gastric emptying of solid was rapid in two (each with less than 100 cm jejunum) and normal in the other five. Gastric emptying of liquid and solid for patients with jejunum in continuity with the colon was normal for the first three hours. There was increased liquid and solid retained in the stomach at six hours in both groups of patients (p < 0.01). Small bowel transit time was faster than in normal subjects for liquid in both groups of patients (p < 0.05) and for solid in those with no colon (p < 0.05). Rapid gastric emptying of liquid may contribute to the large stomal output in patients with a high jejunostomy. Preservation of the colon after a major small intestinal resection exerts a braking effect on the rate of early gastric emptying of liquid.     

Intestinal transit in anxiety and depression.

BACKGROUND: Patients with anxiety and depression often have bowel symptoms. Until now, studies investigating a link between altered bowel habit and psychological illness have focused on patients with disturbed defecation presenting to gastroenterologists. AIMS: To determine whether patients with anxiety and depression have objective evidence of abnormal intestinal transit irrespective of any bowel symptoms. METHODS: 21 psychiatric outpatients fulfilling research criteria for generalised anxiety disorder and/or major depression, and 21 healthy volunteers were studied. Orocaecal transit time (OCTT) was measured by lactulose hydrogen breath test. Whole gut transit time (WGTT) was measured by abdominal radiography after ingestion of radio-opaque markers. RESULTS: Median (range) WGTT was shorter in patients with anxiety (14 (6-29) hours) than in patients with depression (49 (35-71) hours) (p < 0.001), and controls (42 (10-68) hours) (p < 0.001). In patients with anxiety, orocaecal transit time was shorter (60 (10-70) minutes) than in patients with depression (110 (60-180) minutes) (p < 0.01), and shorter than in controls (75 (50-140)) minutes (p < 0.05). The prolongation of transit times in depression compared with controls was not significant. However, WGTT correlated with both the Beck Depression Inventory score (r = 0.59, p < 0.01) and the depression score of the Hospital Anxiety and Depression scale (r = 0.66, p < 0.001). CONCLUSIONS: These objective measurements of intestinal transit in affective disorders are consistent with clinical impressions that anxiety is associated with increased bowel frequency, and depressed patients tend to be constipated; mood has an effect on intestinal motor function.     

Failure of tropisetron to inhibit jejunal water and electrolyte secretion induced by 5-hydroxytryptamine in healthy volunteers.

The effects of the 5-hydroxytryptamine (5-HT3) receptor antagonist, ICS 205-930 (tropisetron), on basal and 5-HT induced jejunal secretion of water and electrolytes were examined using a double blind, randomised crossover design. In seven healthy volunteers steady state perfusions of the proximal jejunum were performed twice with the Loc-I-Gut tube after 5+5 mg ICS 205-930 or placebo capsules were given. After equilibration for 60 minutes and completion of a 120 minute basal period 5-HT (10 micrograms/kg x min intravenously) was infused for 120 minutes. Net water absorption (mean (SEM)) in the basal period was 0.55 (0.84) ml/cm x h and 0.74 (0.72) ml/cm x h after placebo and ICS 205-930, respectively (p > 0.05). Infusion of 5-HT caused significant net secretion of water after placebo (2.05 (0.58) ml/cm x h; p < 0.02) as well as ICS 205-930 (2.60 (0.89) ml/cm x h; p < 0.05). As ICS 205-930 excerted no effects on either basal or 5-HT induced water and electrolyte transport in the intact human jejunum the compound is probably not efficacious as an anti-secretory drug in patients with 5-HT induced diarrhoea.     

Rapid distal small bowel transit associated with sympathetic denervation in type I diabetes mellitus.

BACKGROUND: The pattern of progression of a meal from the stomach to the caecum in diabetes mellitus is controversial and the differential roles of transit through the jejunum and the ileum have not been investigated in diabetes. AIMS: To determine gastric emptying and transit rates through proximal and distal regions of the small bowel in type I diabetic patients. SUBJECTS: The study included six diabetic patients with evidence of autonomic neuropathy (DM-AN group), 11 diabetics without autonomic dysfunction (DM group), and 15 control volunteers. METHODS: Gastric emptying and small bowel transit of a liquid meal were evaluated scintigraphically in these subjects. Transit through regions of interest corresponding to the proximal and distal small intestine up to the caecum was determined and correlated with gastric emptying rates, cardiovascular measurements of autonomic function, and the occurrence of diarrhoea. RESULTS: Gastric emptying and transit through the proximal small bowel were similar in the three groups. The meal arrived to the caecum significantly earlier in DM-AN patients (median; range: 55 min; 22-->180 min) than in the DM group (100 min; 44-->180 min, p < 0.05) or in controls (120 min; 80-->180 min, p < 0.02). Accumulation of chyme in the distal small bowel was decreased in DM-AN patients, who showed values for peak activity (30%; 10-55%) significantly lower than in the DM group (49%; 25-77%, p = 0.02) and controls (50%; 30-81%, p = 0.02). In DM patients (n = 17), the time of meal arrival to the caecum was significantly correlated with both orthostatic hypotension (coefficient of contingency, C = 0.53, p < 0.01) and diarrhoea (C = 0.47, p < 0.05), but not with gastric emptying rates. CONCLUSIONS: Patients with type I diabetes mellitus and sympathetic denervation have abnormally rapid transit of a liquid meal through the distal small bowel, which may play a part in diarrhoea production.     

Effect of jejunal infusion of bile acids on small bowel transit and fasting jejunal motility in man.

The effect of jejunal infusion of glycochenodeoxycholic acid and glycocholic acid on small bowel transit time, fasting jejunal motility and serum bile acid concentrations was investigated in groups of five to six healthy subjects. Glycochenodeoxycholic acid at a concentration of 15 mmol/l (total amount: 5 mmol) and glycocholic acid 15 mmol/l (total amount: 5 mmol), both with lecithin 2.5 mmol/l, delayed (p less than 0.02) small bowel transit when compared with a bile acid free infusion [158.3 (12.5) min v 111.7 (17.6) min and 103.3 (21.8) min v 70.0 (14.9) min], inhibited (p less than 0.01 and p less than 0.05 respectively) the percentage duration of pressure activity of phase 2 [13.1 (1.8)% v 28.1 (3.4)% and 29.2 (5.5)% v 34.9 (3.9)%], but did not change duration of migrating motor complex, or of its phases. Glycochenodeoxycholic acid 10 mmol/l (total amount: 3.3 mmol), either with or without lecithin, did not delay small bowel transit significantly [145.0 (13.2) min v 115.0 (19.5) and 90.0 (11.7) min v 84.0 (8.3)]. When bile acids were infused, serum bile acid curves were similar to those obtained after a liquid meal and the peak serum bile acid concentration occurred 33.7 (6.6) min before (p less than 0.001) completion of small bowel transit. These observations suggest a role for endogenous bile acids in the regulation of small gut motility.     

Bile salt inhibition of motility in the isolated perfused rabbit terminal ileum.

The effects of bile on small bowel motility were studied in isolated, perfused rabbit terminal ileum. It was proposed that bile delivery into the distal ileum would inhibit ileal motor activity, by peptide YY (PYY) release and therefore the effect of luminal bile on motor activity was examined and PYY release measured. Luminal bile and taurocheodeoxycholic acid (10 mmol) inhibited ileal motor activity. Arterial infusion of venous effluents from a bile inhibited ileum suppressed motor activity in a second isolated ileum. This shows the presence of a humoral inhibitor of ileal motor activity. Luminal bile increased venous PYY concentrations (42.5 (8.5) to 502 (46.2) pmol/l; p < 0.01) and increased bile salt values (1.7 (0.36) to 88.6 (5.6) 10 mumol/l/l; p < 0.005). Arterial infusion of taurocheodeoxycholic acid at concentrations found in the venous effluent (100 mumol/l/l) suppressed motility (p < 0.001) but infusion of PYY at concentrations in the venous effluent (500.0 pmol/l) failed to inhibit motility. Furthermore, PYY antagonist, PYX 1, failed to reverse the bile induced inhibition of motility. Luminal bile salts inhibit terminal ileal motility and this is independent of PYY release. By slowing motility, bile salts may participate in their own absorption by the 'ileal pump' and in the 'ileal brake' mechanism.     

Intestinal motor activity in experimental hyperthyroidism in conscious dogs

The small intestinal motor effects of experimental hyperthyroidism were studied in 8 conscious dogs to reveal possible mechanisms of accelerated small bowel transit in hyperthyroidism. Six strain gauge transducers were implanted on the small intestine of each dog. Long-term hyperthyroidism was induced by subcutaneous administration of 100 and 200 micrograms/kg.day of thyroxin. Application of thyroxin did not interrupt the cyclic fasting motor activity. Thyroxin (100 micrograms/kg.day) caused a slight increase in the period of the migrating motor complex (p less than 0.05). The maximum contractile frequency rose dose-dependently up to 11% (p less than 0.05). During phase 2 and the digestive state the contraction frequency increased up to 29% and 27%, respectively (p less than 0.05). More contractions occurred in groups during the digestive state in hyperthyroidism. Half of the dogs showed giant migrating contractions during thyroxin administration, whereas those contractions were not observed during the control period. We conclude that fasted and postprandial intestinal motility is changed in experimental hyperthyroidism. Acceleration of small bowel transit may be caused by changes in contractile pattern of phase 2 and the digestive state or by the increased frequency of giant migrating contractions.