SEARCH · PubMed Health

Results for “Myoelectric Complex, Migrating”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources

PubMed1976

Insulin and jejunal electrical activity in dogs and sheep.

The effect of insulin on jejunal myoelectric activity was studied in conscious dogs and sheep by injection of insulin and stimulation of insulin release. In dogs, the migrating myoelectric complex (MMC), characteristic of fasting, was replaced by a continuous pattern of activity after feeding, injection of insulin, or infusion of D-glucose, L-leucine, or L-arginine. The response to feeding was reduced in alloxan-diabetic dogs and completely abolished following additional vagotomy when only exogenous insulin induced the "fed" pattern. Vagotomy alone had only minor effects on the response to feeding. Sheep exhibit a continuous sequence of MMC, regardless of feeding, but infusion of insulin or volatile fatty acids produced activity similar to that seen after feeding in dogs. In alloxan-diabetic sheep the recurrence and intensity of the MMC were decreased, and the effect of volatile fatty acids was eliminated. Insulin injection restored the pattern to normal. Thus, insulin levels are of importance in the control of the jejunal motor profile and may mediate the postprandial disappearance of MMC in dogs.

Animals↗

PubMed2001

Small bowel motility and colonic transit are altered in dogs with moderate renal failure.

Although gastrointestinal complications are common in patients with renal disease, the effects of renal dysfunction on bowel motility and gut transit times are not well known. We assessed gastrointestinal electromyographic activity, gastric emptying rate, orocolonic transit time, oroanal transit time, and xylose absorption before and after surgically inducing a 66% decrease in glomerular filtration rate in dogs. Moderate renal failure induced no gross or microscopic gastrointestinal lesions but caused a 16-42% increase in gastrointestinal motility indexes. We found a 24% decrease in the propagation velocity of the myoelectrical migrating complex in the duodenojejunal segment, a 30% decrease in phase I duration in duodenal and jejunal regions, a 20% increase in the total irregular electrical activity of the small intestine, and a 22% increase in duration of the meal response in the duodenum and jejunum. Renal failure did not change xylose absorption, gastric emptying rate, and orocolonic transit time but decreased colonic transit time by 38%. The mean weight of feces was increased. These results indicate that moderate renal failure alters duodenojejunal motility and decreases colonic transit time.

Animals↗

PubMedDate not supplied

Does botulinum type-A toxin affect motor activity after proctocolectomy and ileal pouch-anal anastomosis? An experimental study in dogs.

AIM OF THE STUDY: The use of anticholinergic drugs has provided a useful therapeutic approach to reduce stool frequency in patients with proctocolectomy and ileal pouch-anal anastomosis (IPAA). Botulinum type-A (BTA) toxin has been shown to specifically block acetylcholine release in the intestinal wall. Therefore this study investigated the effect of BTA on small intestinal and J-pouch motility after IPAA. MATERIAL AND METHODS: Proctocolectomy and IPAA were performed in 4 dogs. The motility of the small intestine and the ileal pouch was recorded by serosal electrodes and strain gauge transducers. The intestinal transit time was determined radiologically and pouch compliance was determined manometrically. Multiple measurements were performed before and after endoscopic injection of BTA into the pouch wall. RESULTS: This treatment did not significantly influence stool frequency, intestinal transit time or pouch compliance. Intrinsic pouch motility was characterized by irregular contractions, the amplitudes and frequencies of which remained unchanged after BTA administration. With the exception of lower contraction amplitudes directly proximal to the pouch, there were no significant differences in the characteristics of the migrating myoelectric complex or in the fed pattern of the small intestine and ileal pouch. CONCLUSIONS: BTA does not significantly affect ileal pouch motility. The beneficial effects of anticholinergic drugs therefore seem to be due to their multifactorial mode of action and not to the inhibition of cholinergic neurons in the pouch.

Anal Canal↗

PubMed1986

Electromyographic characteristics of small bowel motility in the rat.

Rats are widely used in intestinal motility studies, but no precise observation has yet been carried out on the organization of motility throughout the whole small bowel of the rat. The aim of this work was to investigate the characteristics of small intestinal motility of the rat using an electromyographic technique. The variables describing the pattern of occurrence of the migrating myoelectric complex (MMC) were studied as well as the relative distribution of the 3 phases within the MMC cycles. The mean duration of the MMC was 20 min on the jejunum, and it increased up to twofold along the ileum. The propagation of the MMCs was regular in the jejunum, but about half the MMCs disappeared along the ileum and did not reach the caecum. The electromyographic characteristics of the jejunum are greatly different from those of the ileum, and the motility of a segment is not representative of the whole small bowel motility. Considering these particularities of intestinal motility, rats differ in many details from other species.

Animals↗

PubMed1985

Changes in motility after jejunal and ileal resection: electromyographic study in rats.

The aim of this work was to compare the effects of massive jejunal and ileal resections on intestinal motility using an electromyographic technique. Male Wistar rats were used: in the first group a massive jejunal resection was performed, conserving a 7-cm segment after the ligament of Treitz; the rats of the second group underwent an ileal resection, preserving 7 cm of the terminal ileum. Motility was studied at the 10th and 30th postoperative days by means of electrodes implanted throughout the remaining bowel and was expressed by the pattern of recurrence of the migrating myoelectric complex (MMC). In a fasting state, in both transected and resected animals at the 10th postoperative day, the gradient in the duration of MMC along the intestine still existed. However, on the 30th postoperative day, in animals with jejunal resection only, there was an adaptive process: the duration of MMC in the remaining jejunum was significantly increased to the duration in the ileum. After the end of the postprandial inhibition of the appearance of the MMC, on the 10th postoperative day there was a significant decrease in the duration of MMC in the ileum in both types of resection, compared to the controls. However, on the 30th postoperative day, the duration of MMC returned to its control value. In conclusion, jejunal resection seems to induce more important adaptive processes in intestinal motility than does ileal resection. The different results are discussed.

Animals↗

PubMedDate not supplied

A peptide from the submandibular glands modulates inflammatory responses.

BACKGROUND: The cervical sympathetic trunk-submandibular gland (CST-SMG) axis plays an important role in inflammation. An immunoregulatory heptapeptide, submandibular gland peptide T (SGP-T), was isolated from submandibular glands, and several of its biological activities have been identified. RESULTS: SGP-T reduced shock-induced hypotension and allergen-induced disruption of migrating myoelectric complexes and the magnitude of smooth muscle contraction. The heptapeptide inhibited the influx of neutrophils into carrageenin-soaked sponges. CONCLUSION: SGP-T has several biological activities that collectively help explain the ability of the CST-SMG axis to regulate inflammation.

Anaphylaxis↗

PubMed1982

Relationship of sphincter of Oddi spike bursts to gastrointestinal myoelectric activity in conscious opossums.

The oppossum sphincter of Oddi (SO) exhibits peristaltic spike bursts with accompanying contraction waves that originate proximally in the sphincter of Oddi and propagate toward the duodenum. In this study we recorded myoelectrical activity of the opossum SO and upper gastrointestinal tract in six conscious animals using chronically implanted electrodes. Biopolar electrodes were implanted in the gastric antrum, duodenum, SO segment, jejunum, and ileum. During fasting the frequency of SO spike bursts, scored as number per minute, showed a cyclic pattern consisting of four phases (A to D). Phase A had a low spike burst frequency of approximately 2/min that lasted approximately 20 min. In phase B, the spike burst frequency increased progressively during a 40-45 min interval culminating in a short interval of phase C activity characterized by a maximal spike burst frequency of approximately 5/min. During phase D, the spike bursts decreased over 15 min to merge with the low frequency of phase A and the cycle repeated. Cycle length of the interdigestive SO cycle, 87+/-11 SD min, was virtually identical with that of the interdigestive migrating myoelectric complex (MMC) of the upper gastrointestinal tract. The onset of phase C activity in the SO began 1-2 min before phase III of the MMC activity in the duodenum. Feeding abolished the cyclic pattern of spike burst activity in the SO as well as in the upper gastrointestinal tract. After feeding the SO spike bursts occurred at a frequency of 5-6/min for at least 3 h. We conclude that: (a) During fasting, the oppossum SO exhibits cyclic changes in its spike burst frequency; (b) Maximal spike burst frequency of the SO occurs virtually concurrent with passage of phase III MMC activity through the duodenum and; (c) Feeding abolishes the interdigestive cyclic spike burst pattern of the SO as well as that of the gastrointestinal tract.

Action Potentials↗

PubMedDate not supplied

Gastric retention of enteric-coated magnesium chloride tablets.

OBJECTIVE: To describe a patient with gastric retention of enteric-coated magnesium chloride tablets. Potential drug and disease etiologies accounting for failure to empty this dosage form are discussed. DESIGN: Single case report. CASE SUMMARY: A seriously ill patient with metastatic small-cell lung cancer accumulated 21 enteric-coated magnesium chloride tablets in his stomach during a four-day administration period. The patient had gastroscopic evidence of mild pylorospasm and suspected gastric motor dysfunction. The latter may have been the result of several factors including concurrent use of oxycodone, vagal dysfunction from chronic alcoholism and cisplatin-based chemotherapy, and possibly a paraneoplastic neuromuscular syndrome involving the gastrointestinal tract. CONCLUSIONS: Enteric-coated tablets are indigestible solids, often of considerable size. Strong antral contractions, associated with phase 3 of the interdigestive migrating myoelectric complex, are usually required to carry such dosage forms through a normal pyloric channel and into the duodenum. Seriously ill patients who may have gastric hypomotility or pyloric channel narrowing are probably not good candidates for therapy with large enteric-coated dosage forms.

Aged↗

PubMed1990

Effects of epidermal growth factor on gastrointestinal electromyographic activity of conscious sheep.

Adult sheep were infused with depilating doses of epidermal growth factor (EGF) at 4 micrograms/kg per h for 24 h. Food was available ad libitum during recording of integrated electromyographic (EMG) activity of the gastrointestinal tract. In comparison with control sheep infused with saline, EGF reduced the frequency of A and B sequences of contraction of the reticulum and rumen over the 24-h period, an effect attributable to the consumption of less food. During the 24-h infusion, EGF stimulated phase III migrating myoelectric complex (MMC)-like activity of the duodenum with an associated decline in the EMG of the abomasal antrum. Infusion of EGF for 1 h at 2.5 and 5.0 micrograms/kg per h in fasted animals produced inhibitory effects on the frequency of A sequences of contraction of the reticulum and rumen during the infusion, and on the amplitude of the ruminal EMG during, and in the hour following, infusion. Phase III MMC-like activity of the duodenum was stimulated by EGF in fasted animals. It is concluded that in fed sheep, depilating doses of EGF have inhibitory effects on the EMG activity of the reticulum and rumen through reductions in food consumption and by other undefined mechanisms. Additional effects of EGF on the gastrointestinal tract of sheep include stimulation of duodenal phase III MMC-like activity.

Abomasum↗

PubMed2002

Myoelectric activity of the spiral colon in dairy cows.

OBJECTIVE: To describe myoelectric activity of the spiral colon in healthy cows. ANIMALS: 7 lactating Simmental X Red-Holstein crossbred cows. PROCEDURE: Cows were implanted with 7 pairs of bipolar silver electrodes (4 in the spiral colon and 1 each in the cecum, distal part of the ileum, and proximal loop of the ascending colon [PLAC]). Myo-electric activity was recorded during 4 days for each cow. Patterns were analyzed, using computer-based methods. RESULTS: Myoelectric activity of the spiral colon was closely associated with motility of the ileum and PLAC and showed the typical organization of migrating myoelectric complexes (MMC). The MMC in the bovine spiral colon (bcMMC) had a mean +/- SD duration of 188.6 +/- 30.8 minutes and was divided into 4 phases. Phases I and II lasted 11.3 +/- 1.4 and 159.4 +/- 33.3 minutes, respectively. Phase III (duration, 5.4 +/- 1.2 minutes) was characterized by 5.2 +/- 0.9 regular spindles (35.4 +/- 5.4 seconds) and 1 final elongated spindle (137.2 +/- 56.4 seconds). Phase III most commonly (73.8 +/- 16.1%) was followed by phase IV (duration, 173 +/- 3.6 minutes). Propagation velocity of phase III was 4.4 +/- 0.5 cm/min, and 13.6% of bcMMC were incompletely propagated through the spiral colon. CONCLUSIONS: Myoelectric activity of the bovine spiral colon is composed of a recurring cyclic pattern similar to MMC of the small intestine. Data of colonic myoelectric activity in healthy cows will serve as a basis for studies on cecal dilatation and dislocation in cattle.

Animals↗

PubMed1996

The regulation of intestinal metabolism and its impact on whole animal energetics.

In digesting and absorbing dietary nutrients, the gastrointestinal tract consumes approximately 20% of all incoming energy. A substantial proportion of this consumption is due to the rapid turnover of cellular protein, which permits abrupt changes in gut size to occur, matching capacity with delivery. If it is size of the alimentary tract that constrains nutrient uptake, greater than 20% allocation of ME intake above maintenance to the gut would improve the growth rate of a young animal but the efficiency of ME utilization for growth would deteriorate. Less than 15% allocation in birds seems injurious to both growth rate and efficiency of growth. Nutrient transport capacity of the intestine may be modulated independent of size; in the case of glucose, an up- or down-regulation of the number of brush-border glucose transporters matches absorptive capacity with delivery. The maximum uptake capacity of a small intestine for glucose at any moment in time is a function of its length, the flow rate of digesta, and the distributed-in-space kinetic parameters of transport (e.g., Vmax and Km). An example maximum uptake capacity for glucose in sheep is calculated at 2,112 g/d, assuming continuous digesta flow. Intermittency of flow reduces the uptake capacity to a functional level of 295 g/d, demonstrating a constraining influence of the periodicity of the migrating myoelectric complex. Growth regulation by stimulatory and inhibitory mitotic signals is presented as a candidate for an energy-independent determinant of the upper limit to functional maximum uptake capacity of the small intestine. Both size and functional capacity of the intestine must be considered in assessing the impact this tissue may have on the rest of the animal.

Animals↗

PubMed2000

A dynamic model of protein digestion in the small intestine of pigs.

A dynamic mathematical model of the digestion of proteins in the small intestine of pigs was developed. The model integrates current knowledge on the transit of digesta along the small intestine, endogenous secretions, digestion of proteins, and absorption of amino acids into a mechanistic representation of digestion. The main characteristics of the model are the following: the small intestine is divided into several segments of variable length but with equal digesta retention time; the rate of transfer of digesta between segments is based on the progression of myoelectric migration complexes; pancreatic and biliary secretions are poured into the first segment, whereas intestinal secretions enter all intestinal segments; protein hydrolysis is described by first-order equations; and an intestinal absorption capacity is used to estimate absorption of hydrolyzed protein. Simulation results are consistent with observed data, although more information is needed to represent reality more closely. The sensitivity analysis shows that parameters for protein hydrolysis largely determine protein digestibility. The absorption capacity of the small intestine limits the absorption of amino acids at the beginning of a meal and modulates the appearance of amino nitrogen in the portal vein. It also shows that amino acid absorption can be limiting to protein digestibility when large amounts of protein are eaten in a single daily meal. The model is useful in evaluating the dynamics of protein digestion and absorption of feedstuffs. The model can be used in evaluating protein digestion of different feedstuffs and feeding strategies.

Animals↗

PubMed1985

Correlation between peptide YY-induced myoelectric activity and transit of small-intestinal contents in rats.

The effect of peptide YY (PYY) on the myoelectric activity of the small intestine was studied in relation to the transit of a 51Cr marker solution in fasted conscious rats. The myoelectric activity was recorded by means of bipolar electrodes implanted at 5, 20, and 35 cm from the pylorus. The marker was administered in the duodenum immediately after an activity front of a migrating myoelectric complex (MMC) had passed the first recording site. Under control conditions, the propagation of one activity front over the three recording levels was accompanied by the propulsion of 90.2 +/- 11.4% of the total radioactivity as one portion distal to the third electrode site. The median peak of the radioactivity was recovered at a distance approximately twice that propagated by an activity front. Intravenous infusion of PYY (50 pmol X kg-1 X min-1) had no effect on the occurrence of the MMC in the duodenum but interrupted its distal propagation and almost totally abolished the spiking activity in the jejunum. In comparison with controls, the transport of the marker was significantly retarded, and the median peak of the radioactivity was recovered proximal to the third electrode site. The results indicate that the small-intestinal contents are propelled as one portion in front of a propagating activity front. The inhibition of the activity front by PYY may account for the delay in the transit of the small-intestinal contents.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

PubMed1986

Physiological role of somatostatin in the digestive tract: gastric acid secretion, intestinal absorption, and motility.

Somatostatin is found in both endocrine cells and nerve fibres of the gastrointestinal tract and has several inhibitory effects on the digestive tract. Somatostatin is a potent inhibitor of gastrin release; its secretion is regulated predominantly by the cholinergic pathway, which inhibits somatostatin and thus stimulates gastrin release. Gastric acid secretion is inhibited by both the paracrine and circulating peptide (hormonal) effects of somatostatin. Somatostatin secretion is a direct effect of acid on the somatostatin cell, since it is unaffected by the axonal blocker tetrodotoxin. Somatostatin antiserum eliminates the inhibitory effect of somatostatin and thus augments acid secretion. It therefore appears that somatostatin plays a physiological role in regulating gastric acid secretion, and it is possible that a lack of the inhibitory function of somatostatin is an aetiological factor in peptic ulcer disease. Postprandially, a rise in serum somatostatin concentration occurs which is twice as high with protein and fat as it is with carbohydrates. Several studies have shown that somatostatin inhibits nutrient absorption, indicating that somatostatin might be a physiological regulator in the homeostasis of ingested nutrients by modulating the intestinal absorption rate. Experiments have also demonstrated that somatostatin infusion inhibits intestinal motility; the interval between migrating myoelectric complexes is increased, and transit time is increased.

Animals↗

PubMed1988

Cisapride induces clustered spikes and irregular spiking of the small intestine of the rat.

The aim of the present study was to investigate the effect of cisapride on the myoelectric activity of the small intestine in the rat. Intestinal myoelectric activity of fasted conscious rats was monitored by three bipolar electrodes chronically implanted at 5, 15 and 25 cm distal to the pylorus and connected to an EEG amplifier. In the basal state, regularly occurring migrating myoelectric complexes (MMCs) and clustered spikes were registered. Cisapride at doses of 0.5-4.0 mg-1 i.v. did not affect the MMCs, but at 8 mg kg-1 i.v. the regular MMCs were replaced by irregular spiking activity (p less than 0.05). Concomitantly cisapride increased the occurrence of clustered spikes and abbreviated the interval between them in a dose-dependent manner (p less than 0.05), without affecting their duration. Hexamethonium at a dose of 10 mg kg-1 i.v. abolished the MMCs as well as the stimulatory effect of ciSapride (4 mg kg-1). Atropine at a dose of 1 mg kg-1 i.v. did not affect the MMCs but blocked the stimulatory effect of cisapride (4 mg kg-1). It is concluded that cisapride induces clustered spikes and irregular spiking. These effects require intact cholinergic pathways, involving both muscarinic and nicotinic receptor mechanisms.

Animals↗

PubMed1995

Non-invasive electrogastrography. Part 1: Correlation between the gastric electrical activity in dogs with implanted and cutaneous electrodes.

Experiments were made on dogs with bipolar silver ball-shaped electrodes chronically implanted on the muscle wall of the stomach. The electrical activity of the gastric muscle wall (electrogastromyogram-EGMG) was characterized by slow potential changes during the quiescent period of the migrating myoelectric complex (MMC) and bursts of spike potentials during the activity period of MMC. Cutaneous (surface) electrodes were placed on the abdominal wall. Waves with a rhythm of 4.5-5 cpm were led off by the cutaneous electrodes (electrogastrogram-EGG), simultaneously with the EGMg. The bursts of spike potentials with the slow gastric potentials in the EGMG corresponded to an increase of the amplitude of the waves in the EGG. Good correlation was found between the number and frequency of spike potentials in a group and the wave amplitude in the EGG. EGG recorded on an electrogastrograph designed by us was characterized by low-amplitude waves corresponding to the slow waves during the period of quiescence of MMC and high-amplitude waves corresponding to the bursts of spike potentials during the activity period of MMC. Therefore it is possible to determine the MMC of the stomach by the changes in the amplitude of the waves in the EGG.

Action Potentials↗

PubMed1998

Non-invasive registration of the aboral and oral spreading of the gastroduodenal peristaltic activity (experimental and clinical investigations).

The electrical activity of the stomach and the upper part of the small intestine of healthy volunteers and patients with nausea and vomiting was recorded non-invasively on an original electrogastrograph. Two kinds of waves were distinguished according to their amplitude: low-amplitude waves, corresponding to the period of quiescence of migrating myoelectrical complex (MMC) and about twice higher in amplitude waves, characterising the periods of activity of MMC (peristaltic activity). There was also some difference between the low- and high-amplitude waves from the small intestine. Sequence of high-amplitude waves recorded from the stomach was followed usually by sequence of high-amplitude waves from the small intestine, presenting the aboral spreading of an activity period of MMC from the stomach to the small intestine. In some patients however, high-amplitude waves were led off first from the duodenal record and after that high-amplitude waves appeared in the gastric record. This suggests an oral spreading of the peristaltic activity (antiperistalsis). Experimental model of antiperistalsis was performed on dogs with chronically implanted electrodes on the gastric and duodenal muscle wall. Carbachol 5 micrograms/kg i.m. evoked bursts of spike potentials first with duodenal slow waves and after that with the gastric slow potentials. The antiperistaltic spreading of the spike activity in dog corresponded to the appearance of high-amplitude waves first in the record of the human small intestine, followed by sequence of high-amplitude waves in the stomach. Thus, the non-invasive recording of the electrical activity of the stomach and small intestines gives reliable information about the direction of the spreading of the peristaltic activity.

Algorithms↗

PubMed1975

[Effect of insulin on electric activity of sheep jejunum].

The effect of insulin on the electrical activity of the small intestine was studied in both normal and alloxan induced diabetic sheep. In normal animals the migrating myoelectric complexes recur at intervals of about 90 min. In the diabetic sheep, the complexes recur at only 2 hourly intervals and administration of insulin restored the pattern to normal. Since in normal sheep, insulin slightly increases the activity and volatile fatty acids, which release insulin do likewise, one may conclude that insulin may control the activity of the gut.

Animals↗