Colonic Motor Activity Research Articles

Colonic myoelectrical activity in IBS painless diarrhoea.

Colonic myoelectrical activity was recorded during 24 hours in 23 patients with painless diarrhoea and compared with a control group of 10 healthy subjects without digestive functional disorders. Diurnal fasting activity showed no significant difference in the total long spike bursts activity (LSB lasting greater than 7 seconds), but short spike bursts activity (SSB, lasting less than 7 seconds) was significantly lower (p less than 0.05) in diarrhoeal patients. A striking difference was observed in colonic response to eating, with an increased number of migrating long spike bursts (MLSB: mass movements) during the first postprandial hour in diarrhoeal patients (p less than 0.001), while short spike bursts (segmental activity) were almost absent in the rectosigmoid area. A marked decrease in the retrograde LSB activity was also observed in eight patients. During the night (from 2200 h to 0600 h) the number of migrating long spike bursts was increased in the diarrhoea group, but almost absent in controls (p less than 0.001). This study shows that colonic motor activity was altered in painless diarrhoea. These disturbances were not limited to the decreased SSB activity in the sigmoid, but involved the whole colon, with lower SSB activity and abnormal increase of migrating long spike bursts activity (MLSB) in postprandial and nocturnal periods.

Effects of oral laxatives on colonic motor complexes in dogs.

The effect of oral laxatives on the organisation of colonic motor complexes was investigated in four conscious dogs. Six strain gauge transducers were implanted on the colon of each dog. After a control period of two to three hours, dogs were orally dosed with 1, 2, or 4 ml/kg of castor oil, or 0.5 g/kg magnesium citrate. Oral olive oil, 4 ml/kg, was used as control. The recording was continued for another 10 hours or until defecation occurred. Each dog showed spontaneous cyclic bursts of contractions (contractile states) at all recording sites during the control period. Contractile states migrating orad or caudad over at least half the length of the colon were called colonic migrating motor complexes (CMMC). Castor oil and magnesium citrate significantly increased the period of colonic motor complexes, but olive oil had no significant effect. None of the above substances changed the percentage of orad migrating motor complexes, as compared with the control values. Periods in which colonic motor activity was completely absent for at least 60 min over at least three consecutive recording sites occurred more frequently after all of the substances. The occurrence of these periods of inhibition, however, was not a consistent feature and there seemed to be no relationship between the occurrence of inhibitory periods and defecation during the recording period. The dogs defecated within 10 hours after administration of magnesium citrate, 1, 2, and 4 ml/kg of castor oil in 12.5, 25, 37.5, and 88.8% of experiments respectively, but never with olive oil. Defecation was generally accompanied by giant migrating contractions in the colon. We conclude that oral laxatives, magnesium citrate and castor oil have a profound effect on colonic motor complexes and colonic motor activity. The period of CMMC is significantly prolonged after their oral administration because of an increased number of non-migrating motor complexes or periods of inhibition of motor activity.

Impact of neodecortication on colon motor response to a meal in the rat.

The colon motor response to a meal consisting of 100 mM of sodium oleate was assessed before and after neodecortication in male Sprague-Dawley rats. Recording probes were anchored surgically in the ascending and descending colon. Pressure changes were recorded on a dynograph using a low-compliance perfusion system. A motility index took into account the amplitude, duration, and frequency of contractions. Neodecortication increased the motility index of the distal colon in the fasting state. However, removal of the cerebral cortex did not affect significantly the colon motor response to a meal. Meal stimulation increased the motility index before and after neodecortication. These findings suggest that resting colonic motor activity is increased after neodecortication, probably through the loss of an inhibitory influence of the central nervous system; and the cerebral cortex is not required for the colon response to a meal in the rat.

Transverse and sigmoid colon motility in healthy humans: effects of eating and of cimetropium bromide.

There have been few studies of the motility of the colon proximal to the rectosigmoid area. For this purpose we evaluated (1) fasting and postprandial transverse and sigmoid colon motor activity and (2) the effects of a new nonselective anticholinergic drug, cimetropium bromide, on transverse and sigmoid motor responses to eating. Two paired studies were carried out in 11 healthy volunteers by means of a colonscopically positioned manometric probe. After placebo, eating significantly increased transverse and sigmoid motility indices throughout the recording period. Cimetropium significantly reduced the motor responses to eating in both the transverse and the sigmoid colon.

Twenty four hour manometric recording of colonic motor activity in healthy man.

The motor activity of the transverse, descending, and sigmoid colon was recorded for 24 hours in 14 healthy volunteers with a colonoscope positioned catheter. During the study the patients ate two 1000 kcal mixed meals and one continental breakfast. Colonic motor activity was low before meals and minimal during sleep; the motility index increased significantly after meals and at morning awakening. Most of the motor activity was represented by low amplitude contractions present singly or in bursts, which showed no recognisable pattern. All but two subjects also showed isolated high amplitude (up to 200 mmHg) contractions that propagated peristaltically over long distances at approximately 1 cm/sec. Most of these contractions occurred after morning awakening, and some in the late postprandial period, with a mean of 4.4/subject/24 h. The peristaltic contractions were often felt as an urge to defecate or preceded defecation, and could represent the manometric equivalent of the mass movements.

Systemic sclerosis: Colon motor and myoelectric activity

Systemic sclerosis: Colon motor and myoelectric activity

The neurovisceral and electrodiagnostic evaluation of patients with thoracic spinal cord injury.

We studied nine patients with complete thoracic spinal cord injury in order to investigate distal electrophysiologic and end organ function. Studies included motor and sensory nerve conduction velocities, spinal and cortical somatosensory evoked responses, bulbocavernosus reflex responses, cystometry and colonic compliance, motor and myoelectrical activity. These studies confirmed an intact peripheral nervous system, as well as normal nerve root, cauda equina, conus medullaris and distal spinal cord function. Cystometry demonstrated decreased bladder capacity and inability to suppress detrusor contractions. Colonic compliance was greatly reduced, compared to control subjects. While basal colonic motor and myoelectrical activity was normal, these spinal cord injury patients failed to demonstrate the postprandial increase in colonic motor and myoelectric activity seen in normal subjects. These tests allow the clinician to define and document the extent of neuronal injury distal to a transverse myelopathy and to evaluate visceral end organ function.

Effects of thoracic spinal cord transection on colonic motor activity in rats.

The resting colonic motor activity before and consecutively after spinal cord transection was recorded in male Sprague-Dawley rats. Recording probes were anchored surgically in the ascending and descending colon. Pressure changes were recorded on a dynograph using a low compliance perfusion system. A motility index took into account the amplitude, duration and frequency of contractions. Following a baseline recording animals were subjected either to spinal cord transection at T4 level or a sham operation. The recording sessions continued regularly on alternate days for the observation period of 3 weeks. Transection of the thoracic spinal cord markedly reduced the motility index of the distal colon on the first postoperative day. However, the motor activity gradually returned to pre-operative values after 7 days. Sham surgery did not influence the motor activity. These findings suggest that colonic motor activity is influenced by spinal shock and probably by different neural mechanisms mediating proximal and distal activities of the colon in rats.

The effect of stress on colon motor and electrical activity in irritable bowel syndrome.

The present investigation was designed to study the role of stress on the physiologic mechanisms of the colon in irritable bowel syndrome (IBS). Patients with IBS were compared with normal controls during resting and stress (mental arithmetic, cold pressor, and fear stressor). The results indicated that IBS patients had significantly higher motor activity than normals in the resting state but did not differ from them in the mean dominant frequency of the basal electrical rhythm (BER) or the proportion of the time they had 2-4 cycles per minute (cpm) slow-wave activity. Stress significantly increased motor activity in both groups although they did not differ significantly from each other during stress. Stress increased the proportion of 2-4 cpm slow-wave activity in IBS patients, but decreased in the controls. The type of stressor, however, did not influence either motor or electrical activity. Although IBS patients were significantly older than the controls and scored higher on the MMPI scales of Hypochondriasis, Hysteria, and Depression, these factors did not significantly influence differences in motor or electrical activity between the groups. The results are discussed in terms of the role of learning in the colon.

Effect of secoverine HCl on motor and myoelectrical activity of the sigmoid colon in man

AbstractSecoverine hydrochloride is a new synthetic tertiary amine with selective muscarine blocking effect. Its tendency to produce parasympathetic side effects has been claimed to be almost 100 times less than atropine. We studied the role of secoverine on meal‐induced colon motor and myoelectrical activity in 12 healthy volunteers. Intraluminal pressure changes, slow wave activity, and spike frequency of the sigmoid colon as well as a pneumogram, blood pressure, and electrocardiogram were monitored. Fifteen minutes after ingestion of a 1000‐kcal meal, subjects received 4 mg secoverine or the same volume of normal saline in separate sessions and recording continued for another 90 minutes. Ingestion of the meal increased colon motor and spike activities; however, these parameters were not influenced by secoverine. Drug treatment did not change the proportion of slow wave activity and did not affect pulse rate, blood pressure, respiration rate, or electrocardiogram in a significant fashion. In conclusion, intravenous injection of 4 mg secoverine had no effect on meal‐stimulated colon motor and myoelectrical activity. Whether this medication at a different dose regimen has therapeutic value remains to be seen. However, this dose of secoverine was well tolerated by the subjects.

Effect of domperidone and dopamine on colonic motor activity in patients with the irritable bowel syndrome.

The effect of domperidone, a peripheral antidopaminergic drug, on sigmoid motor activity in the irritable bowel syndrome, has been evaluated by measuring pressures in 3 opentipped tubes perfused with distilled water at a constant flow rate of 0.636 ml/min and inserted into the sigmoid colon. Domperidone 20 mg i.v. in 10 patients, did not induce any significant change in basal motility, but prevented the increase in motor activity produced by the infusion of dopamine 5 micrograms/kg/min for 10 min. It appears that domperidone had no effect on sigmoid motor activity, although the inhibition of dopamine-induced motility confirms the presence of specific dopaminergic receptors in the colon and the antidopaminergic action of domperidone.

Colonic migrating and nonmigrating motor complexes in dogs.

We report here the characteristics of a cyclic motor activity in the colon of conscious dogs and its relationship to small intestinal migrating motor complexes (MMCs). The colonic motor activity was recorded by four equispaced strain gauges and small intestinal myoelectric activity by four equispaced bipolar electrodes. The colonic motor activity was characterized by rhythmic bursts of contractions. The mean durations of bursts of contractions varied from 7.0 to 11.5 min at the four colonic recording sites. Those bursts of contractions which migrated over at least three recording sites were called colonic migrating motor complexes (CMMCs). All other patterns of bursts of contractions were called colonic nonmigrating motor complexes (CNMCs). A total of 160 CMMCs were recorded during a total recording period of 132 h; 151 CMMCs migrated caudad and 9 orad. The mean period of caudad migrating CMMCs was 53.3 +/- 5.4 (SE) min, and their mean migration time was 11.3 +/- 1.2 (SE) min. The onset of CMMCs was not temporally related to the onset of small intestinal migrating myoelectric complexes in the duodenum or their arrival in the terminal ileum. CMMCs did not have phases I to IV like those of small intestinal MMCs, but two consecutive CMMCs were separated by a quiescent state or by one or more randomly occurring bursts of contractions (CNMCs).

Colonic dysfunction in patients with thoracic spinal cord injury

Severe constipation is a debilitating concomitant of complele traumatic thoracic spinal cord injury. In order to investigate the pathophysiology of this symptom, we studied colonic compliance, as well as motor and myoeleclrical activity, in the fasting and postprandial states and after neostigmine stimulation in 9 patients with clinically and electrophysiologically documented complete thoracic spinal cord injury. Electrophysiologic studies, including nerve conduction velocities, cortical and spinal somatosensory-evoked responses, and bulbocovernosus reflex responses, as well as urinary bladder cystometry, documented normal peripheral somatosensory function, integrity of the distal spinal cord, conus medullaris and cauda equina, and interruption of the somatosensory and descending spinal pathways proximal to the cauda equina. These 9 patients with spinal cord injury demonstrated a decrease in colonic compliance compared with a control group (p < 0.01). They failed to demonstrate the postprandial increase in colonic motor and myoelectrical activity observed in a control group (p < 0.01), but did respond to neostigmine with an increase in both motor and myoelectrical activity (p < 0.02), suggesting an intact myogenic component. In these patients, decreased colonic compliance and absent postprandial colonic motor and myoelectrical activity may be mediated by ablation of outflow from higher centers to the lower spinal cord and may be correlates of visceral neuropathy and severe constipation.

Basal motor activity of the distal colon: A reappraisal

The significance of recent motor data on the distal colon in irritable bowel syndrome is obscured by methodological questions such as bowel preparation, variability and reproducibility of motor activity and segmental differences. Thirty subjects were studied after prior bowel cleansing with a water enema on two separate occasions 1 wk apart (10 with one bowel movement per day, 10 with two to three per week, and 10 with three to 12 per day). Two additional studies were performed in 10 of the subjects, one with and one without prior cleansing. The motility indices of the cleansed and unwashed colon were dissimilar. The motility index per 3 min varied markedly over 3 h, and the indices between the paired studies were rarely identical. Marked segmental differences were noted. The mean motility index per 3 min of the constipated and the diarrhea groups was significantly greater than that of normals only in the 15-cm segment. In view of these variables, caution should be exercised in the interpretation of basal motor activity of the distal colon.

Electrical activities of the muscle layers of the canine colon.

The spontaneous electrical and mechanical activities of the circular and longitudinal muscle layers of the canine colon were studied. The smooth muscle cells of the circular muscle layer exhibited regular, omni-present myogenic slow-wave activity at a frequency ranging from 4 to 7 c/min. With intracellular micro-electrodes, the slow-wave amplitude was 21-38 mV and its duration 3-6 sec. The 'resting' membrane potential was -60 to -76 mV. Some slow waves had superimposed spike bursts on their peak depolarizations and only these were associated with phasic contractions. It is concluded that they serve a pace-maker function similar to their counterpart in the small intestine. The longitudinal muscle layer exhibited periods of electrical activity alternating with periods of electrical quiescence. During the activity periods electrical oscillations occurred at a frequency of 13-35 c/min with spikes on top of them. Each electrical activity period was associated with a prolonged 'tonic' contraction. The duration of these periods was 30-120 sec and their frequency 0.4-1.1 period/min. This activity is similar to that recorded from the longitudinal muscle of the guinea-pig caecum despite the anatomical differences. The electrical activity periods of the longitudinal muscle appeared to require an excitatory input (stretch and/or acetylcholine release). Provided the strips were not excessively stretched, atropine abolished all electrical and motor activity. Stretching prolonged the electrical activity periods until they eventually fused together and the muscle developed maintained tone. Simultaneously recording from both layers showed that, although electrotonic spread between the two layers is probably insignificant, the activity of the two layers was co-ordinated. Only those slow waves of the circular layer that occurred during the electrical activity periods of the longitudinal layer had superimposed spikes. It is suggested that this co-ordination may indicate that the two muscle layers may be commanded by a common input from periodically active, cholinergic intramural neurones. It is proposed that the complex patterns of colonic electrical and motor activities may be explained as consisting of two major components: one arising from the longitudinal (long spike bursts, high-frequency oscillations and tonic contractions) and the other from the circular layer (slow waves, short spike and phasic contractions). Simultaneous electrical records from the two muscle layers and the mucosa failed to show a consistent relationship between the mucosal record and the activity of either layer. Caution should be exercised in the interpretation of intraluminally derived electrical recordings.

Colonic motility and transit of digesta during hard and soft faeces formation in rabbits.

Rabbits produce hard and soft faeces in a circadian rhythm. This study was undertaken in order to examine the motor function of the colon in relation to the formation of these two types of faeces. Colonic motility was measured in unanaesthetized rabbits using strain-gauge transducers and simultaneous radiography. Three types of contractions were found in the rabbit proximal colon: haustral activity, segmental activity, and mass peristalsis. Distinctly different motor patterns were observed during the formation of hard and soft faeces. When hard faeces were produced, the motor activity of the proximal colon was enhanced. It consisted of segmental and haustral activity. The segmental contractions separated the digesta into faecal pellets and forced them slowly aborad, whereas the movements of the haustra carried the liquid contents back towards the caecum. When soft faeces were produced haustral and segmental activity was reduced and transfer of the digesta through the proximal colon was accelerated by mass movements. In contrast to the proximal colon, the motility of the distal colon was enhanced during the formation of soft faeces and decreased during the production of hard faeces. The results support the concept that hard faeces are chiefly produced by a separation of liquids and solids and by a retrograde transfer of liquid digesta rather than by an increased absorption of water.

Inhibition of postprandial colonic motility by sulpiride in patients with irritable colon.

Sulpiride, a benzamide derivative, selectively antagonizes dopaminergic receptors within and outside the central nervous system. Dopamine has previously been shown to increase colonic motility. In the present investigation the motor response of the pelvic colon to a standard 1000 calorie meal was studied in 12 patients with the irritable bowel syndrome. The meal induced a significant increase in motor activity, lasting for 1 h and greatest in the first 30 min. In 6 cases the administration of sulpiride 100 mg i.m. significantly reduced the postprandial increase in colonic motor activity. Thus dopaminergic receptors may be involved in the colonic motor response to food.

Colonic Dysfunction in Multiple Sclerosis

Multiple sclerosis is a central nervous system disease frequently accompanied by urinary symptoms and severe constipation. In order to investigate the pathophysiology of these symptoms, we studied colonic motor and myoelectrical activity, as well as colonic volume-pressure relationships (colonometrograms) and have correlated these data with cystometry and electrophysiologic studies of the central and peripheral somatosensory nervous system. The study group consisted of 7 patients with advanced multiple sclerosis marked by symptoms and signs of somatic and visceral nervous system dysfunction including severe constipation. Ten normal volunteers served as control subjects. The multiple sclerosis group demonstrated electrophysiologic evidence of lesions in the somatosensory neuroaxis central to the lumbosacral spinal cord. Abnormal cystometrograms suggested visceral central nervous system dysfunction. Colonometrograms in the multiple sclerosis group demonstrated a more rapid pressure rise than in the control group (p less than 0.01). The multiple sclerosis group failed to demonstrate the postprandial increase in colonic motor and myoelectrical activity observed in the control group (p less than 0.01). Abnormal colonometrograms and absent postprandial colonic motor and myoelectric responses may be features of visceral neuropathy in patients with advanced multiple sclerosis and severe constipation.

Glucagon, gastric inhibitory polypeptide and the gastrocolic response

Serosal bipolar electrodes and strain gauge force transducers were placed on the right and left colon in subhuman primates to record spike discharges and circular muscular contractions. The effect of glucagon on colonic motor and electrical activity were studied before and after meals. Serum concentration of gastric inhibitory polypeptide was measured simultaneously 15 minutes before and 45 minutes after eating. Serum levels of gastric inhibitory polypeptide increased in response to eating; pre- and postcibal concentrations were not altered by glucagon. The gastrocolic response of the colon to eating was demonstrated. Glucagon inhibited the intrinsic activity of the entire colon before meals and partly inhibited the right colon after meals. Postcibal left colon activity was not inhibited by glucagon. This indicates that a distinct mechanism accounts for the left colonic postcibal increase in contractile and electrical spike activity. A neural or humoral mechanism is implicated but is not specifically identified.

Motor activity after colon replacement of esophagus: Manometric evaluation

Motor activity of the colon transplant for esophageal reconstruction is a point of controversy. In this paper we present manometric studies carried out in 15 patients subjected to isoperistaltic colon interposition. Manometric studies were carried out with two polyvinyl water-filled catheters inserted through pressure transducers. Basal colonic activity and motor activity following several stimuli and "dry swallows" were registered. The type of waves after stimuli were classified as (1) synchronous, (2) sequential or progressive, and (3) segmental. Details of the basal colonic waves and colon contractions after stimuli are given: i.e., rate, duration, amplitude, interval from the stimulus, and percentage of motor activity. The data reported here indicate the good motor response of the isoperistaltic colon to intraluminal injection of water or 0. 1 N hydrochloric acid and to chachet swallowing. Only two free-symptoms patients did not have motor activity. One of them was submitted to manometric studies too soon after the operation. We conclude that the presence of sequential waves in the interposed segment likely can help to propel the contents of the colon into the stomach and to clear gastric juice if reflux from the stomach should occur.