Effects of PGF2 alpha and of indomethacin on rabbit small and large intestinal motility in vivo

1990 ◽  
Vol 258 (2) ◽  
pp. G231-G237 ◽  
Author(s):  
R. Burakoff ◽  
E. Nastos ◽  
S. Won
Keyword(s):  
Terminal Ileum ◽  
Intestinal Motility ◽  
Contractile Activity ◽  
Distal Colon ◽  
Proximal Colon ◽  
Myoelectric Activity ◽  
Rabbit Ileum ◽  
Spike Potential ◽  
Potential Frequency

Prostaglandin F2 alpha (PGF2 alpha) has been shown to increase contractility in the small intestine and colon in vitro, and increased mucosal prostaglandin synthesis has been reported in ulcerative colitis. The purpose of this study was to determine the effects of PGF2 alpha and of indomethacin on myoelectric and contractile activity in the rabbit ileum and colon in vivo. PGF2 alpha caused an increase in spike potential frequency and contractile activity in the terminal ileum and proximal and distal colon. Indomethacin alone increased spike potential frequency and contractile activity in the terminal ileum and proximal colon but decreased myoelectric activity in the distal colon. It is concluded that PGF2 alpha may play an important role in modulating intestinal motility, especially in the distal colon but to a lesser extent in the terminal ileum and proximal colon.

Comparison of the effects of leukotrienes B4 and D4 on distal colonic motility in the rabbit in vivo

1989 ◽  
Vol 257 (6) ◽  
pp. G860-G864 ◽  
Author(s):  
R. Burakoff ◽  
E. Nastos ◽  
S. Won ◽  
W. H. Percy
Keyword(s):  
Contractile Activity ◽  
Colonic Motility ◽  
Distal Colon ◽  
Mechanical Activity ◽  
Excitatory Action ◽  
Potential Frequency ◽  
Small And Large Intestine ◽  
Related Increase

Leukotrienes (LTs) have been shown to contract smooth muscle of the small and large intestine in vitro, and an increased mucosal synthesis of leukotrienes has been reported to occur in ulcerative colitis. The purpose of this study was to evaluate the effects of LTs B4 and D4 on the myoelectric and mechanical activity of the rabbit distal colon in vivo and to determine how these effects were modified by indomethacin. LTB4 had a weak excitatory action on both electrical and mechanical activity but this was not statistically significant; LTD4 on the other hand caused a significant dose-related increase in spike potential frequency and contractile activity. Indomethacin alone (1 mg/kg) had no significant effect on the electrical or mechanical activity of the colon but blocked the effects of subsequently administered LTD4. It is concluded from these data that at least part of the excitatory action of LTD4 results from its causing the synthesis and release of excitatory prostaglandins. However, whereas leukotrienes have the potential to play an important role in modulating colonic motility, it seems most likely that this effect would occur after pathological stimulus rather than in the normal healthy colon.

Neurohumoral control of colonic motility in the rabbit

1983 ◽  
Vol 245 (4) ◽  
pp. G582-G588 ◽  
Author(s):  
W. J. Snape ◽  
S. Shiff
Keyword(s):  
Contractile Activity ◽  
Control Period ◽  
Colonic Motility ◽  
Distal Colon ◽  
Proximal Colon ◽  
Base Line ◽  
Cholinergic Stimulation ◽  
Bipolar Electrodes ◽  
Neurohumoral Control ◽  
Alpha Adrenergic Agonist

Colonic motility was examined in the proximal (taeniated) and distal (nontaeniated) colon of New Zealand White rabbits. Colonic myoelectric and contractile activities were recorded by bipolar electrodes and extraluminal strain gauges sewn on the antimesenteric serosal surface of the proximal and distal colon. Slow-wave frequency consistently was slower in the proximal colon (13.2 +/- 0.9) compared with the distal colon (15.8 +/- 1.2) (P less than 0.05). During the control period 81.8 +/- 5.2% of slow waves have superimposed spike potentials in the proximal colon. The distal colon had similar amounts of spike activity. The distal colon had increased base-line contractility (P less than 0.02). Atropine inhibited spike and contractile activity on both sides of the colon, but the distal colon still had more contractile activity than the proximal colon (P less than 0.02). The alpha-adrenergic agonist phenylephrine and antagonist phentolamine had no effect on colonic motility. Isoproterenol inhibited colonic smooth muscle spike and contractile activity. This effect was blocked by propranolol. Administration of trimethaphan camsylate caused an increase in spike and contractile activity only in the distal colon. The effect of trimethaphan on the distal colon was inhibited by atropine. These studies show that 1) tonic cholinergic stimulation exists both in the proximal and in the distal colon, 2) circulating catecholamines have minimal effect on base-line colonic motility, and 3) tonic nonadrenergic inhibition of the distal colon modulates the tonic cholinergic stimulation.

Haustral boundary contractions in the proximal 3-taeniated rabbit colon

2016 ◽  
Vol 310 (3) ◽  
pp. G181-G192 ◽  
Author(s):  
Ji-Hong Chen ◽  
Zixian Yang ◽  
Yuanjie Yu ◽  
Jan D. Huizinga
Keyword(s):  
Contractile Activity ◽  
Motor Pattern ◽  
Distal Colon ◽  
Human Colon ◽  
Proximal Colon ◽  
Motor Patterns ◽  
Video Recordings ◽  
Induced Folding ◽  
Phase Amplitude ◽  
Cells Of Cajal

The rabbit proximal colon is similar in structure to the human colon. Our objective was to study interactions of different rhythmic motor patterns focusing on haustral boundary contractions, which create the haustra, using spatiotemporal mapping of video recordings. Haustral boundary contractions were seen as highly rhythmic circumferential ring contractions that propagated slowly across the proximal colon, preferentially but not exclusively in the anal direction, at ∼0.5 cycles per minute; they were abolished by nerve conduction blockers. When multiple haustral boundary contractions propagated in the opposite direction, they annihilated each other upon encounter. Ripples, myogenic propagating ring contractions at ∼9 cycles per min, induced folding and unfolding of haustral muscle folds, creating an anarchic appearance of contractile activity, with different patterns in the three intertaenial regions. Two features of ripple activity were prominent: frequent changes in propagation direction and the occurrence of dislocations showing a frequency gradient with the highest intrinsic frequency in the distal colon. The haustral boundary contractions showed an on/off/on/off pattern at the ripple frequency, and the contraction amplitude at any point of the colon showed waxing and waning. The haustral boundary contractions are therefore shaped by interaction of two pacemaker activities hypothesized to occur through phase-amplitude coupling of pacemaker activities from interstitial cells of Cajal of the myenteric plexus and of the submuscular plexus. Video evidence shows the unique role haustral folds play in shaping contractile activity within the haustra. Muscarinic agents not only enhance the force of contraction, they can eliminate one and at the same time induce another neurally dependent motor pattern.

Effects of physical exercise on colonic motor activity

1991 ◽  
Vol 260 (4) ◽  
pp. G646-G652 ◽  
Author(s):  
M. Dapoigny ◽  
S. K. Sarna
Keyword(s):  
Physical Exercise ◽  
Motor Activity ◽  
Contractile Activity ◽  
Total Duration ◽  
Distal Colon ◽  
Proximal Colon ◽  
Fed State ◽  
Fasted State ◽  
Colonic Motor ◽  
Colonic Motor Activity

We investigated the effect of physical exercise on colonic motor activity in the fasted and fed states in six conscious dogs. Each dog was implanted with nine strain gauge transducers: three on the proximal, three on the middle, and three on the distal colon. The dogs ran for 1 h on a treadmill at 5 km/h (slope 5%). In the fasted state, the dogs exercised during the 5th h of recording after an overnight fast, and in the fed state during the 1st, 3rd, and 5th postprandial hour. In the fasted state, exercise significantly decreased the frequency of colonic migrating motor complexes (MMCs) but had no effect on the total or the mean duration of contractile states in the proximal, middle, and distal colon. Postprandially, exercise disrupted colonic MMCs and replaced them with nonmigrating motor complexes in all three periods of exercise (1st, 3rd, and 6th h). Exercise also increased the total duration per hour of contractile activity throughout the colon during the 1st and 3rd h and only in the distal colon during the 6th h after the meal. The dogs never defecated during rest in the fasted or the fed state. Shortly after the start of exercise in the fasted and fed states, giant migrating contractions (GMCs) occurred, and they were followed by defecation. In approximately 40% of the experiments, another GMC originated in the proximal colon, approximately 10 min after the first defecation, and migrated caudad up to the middle colon. These GMCs were not associated with defecation but caused mass movements.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals A126 RETROGRADE LABELLING OF NODOSE GANGLIA IN VIVO BY FLUORESCENT TRACERS

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 146-147
Author(s):  
A A Tashtush ◽  
A E Lomax
Keyword(s):  
Vagus Nerve ◽  
Principal Component ◽  
Distal Colon ◽  
Proximal Colon ◽  
Vagal Afferents ◽  
Sensory Innervation ◽  
Lower Percentage ◽  
Retrograde Labelling ◽  
Nodose Ganglia

Abstract Background The gut-brain axis is a bidirectional connection between the gastrointestinal tract (GI)and the central nervous system. The vagus nerve has been recognized as a principal component of this axis. Vagus nerve plays important role in maintaining homeostasis and normal GI functions, its afferent fibers can detect microbiota metabolites also. Many studies have demonstrated that the upper GI tract receives dense vagal innervation, which decreases distally throughout the tract. However, the distal colon sensory innervation of the vagus nerve remains controversial. Aims To illuminate the extent to which the vagus nerve innervates the colon, to determine whether anatomical evidence exists for double-labeled vagal afferents supplying the proximal and distal colon in the nodose ganglia. Methods C57Bl/6 mice (n=8) were injected in the proximal and distal colon with alternating solutions of retrograde tracers 1.7% Fast blue (FB) and 5% of lipophilic tracer DiI. Animals were left to recover for 10–13 days then underwent cardiac perfusion. Nodose ganglia were collected and fixed in 4% paraformaldehyde. 12 um tissue sections were then analyzed under a fluorescent microscope at 350nm and 555nm wavelength. Results In total, 27% of nodose cell bodies were labeled from the entire colon. Following proximal DiI injections, the percentage of labeled cell bodies in the nodose ganglia were 24.3± 3.9%. However, we observed a lower percentage of labeled neurons from the distal colon, with 9.3± 1.4% after DiI injections. FB labelling from the distal colon was three times less than that observed for DiI. Within the nodose ganglia, 40% of all distally labelled neurons were labelled with both tracers. Conclusions These findings indicate that in mice, both distal and proximal colon receives visceral sensory innervation from the vagus nerve. Thus, providing evidence for a sensory anatomical connection of the vagus nerve between these two parts of the colon. Funding Agencies CCC, CIHR

Migrating action-potential complexes in vitro in cholera-exposed rabbit ileum

1983 ◽  
Vol 244 (3) ◽  
pp. G291-G294 ◽  
Author(s):  
K. L. Koch ◽  
J. L. Martin ◽  
J. R. Mathias
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Action Potential ◽  
Myoelectric Activity ◽  
Rabbit Ileum ◽  
Whole Cell Lysate ◽  
The Central Nervous System ◽  
Potential Activity

The objective of this study was to determine whether cholera-exposed rabbit ileum exhibits altered myoelectric activity in vitro, without central nervous system connections. Whole-cell lysate of Vibrio cholerae, 100 mg in 1 ml saline, was injected into the jejunum of New Zealand White rabbits. Segments of ileum were removed at 12 and 24 h after inoculation and studied in vitro using myoelectric recording techniques. Propagating ring contractions were visualized and corresponded to intense action-potential activity that propagated over consecutive electrode sites. This altered myoelectric activity was similar to the previously described migrating action-potential complex (MAPC) in vivo after infection of rabbit ileum with live V. cholerae, its wholecell lysate, or the purified enterotoxin choleragen, with one exception. All MAPC activity propagated aborally in the in vivo-infected loops; in contrast 26% of the MAPCs propagated retrograde in the in vitro loops. Control segments were injected with saline, and no in vitro MAPCs were observed. Thus, the MAPC stimulated by cholera toxin may be maintained by the enteric nervous system of the gut wall. Although a role for extrinsic nerves is not excluded, our observations suggest that the small intestine may work autonomously, independent of the central nervous system.

Contribution of neurogenic and myogenic factors in the response of rat proximal colon to distension

1987 ◽  
Vol 252 (4) ◽  
pp. G447-G457 ◽  
Author(s):  
C. A. Maggi ◽  
S. Manzini ◽  
A. Meli
Keyword(s):  
Contractile Activity ◽  
Colonic Motility ◽  
High Amplitude ◽  
Proximal Colon ◽  
Field Stimulation ◽  
Myogenic Factors ◽  
Resting Tone ◽  
Stimulation Of

The response of the rat proximal colon to distension and drugs that interfere with intrinsic and extrinsic nerves was investigated in vivo (urethan anesthesia) and in vitro. Saline distension induced the appearance of a cyclic contractile activity that was slightly inhibited by atropine (ATRO) and enhanced by physostigmine. Hexamethonium increased the distension-induced motor activity. Topical tetrodotoxin (TTX), lidocaine, or procaine produced an increase in motility of the proximal colon. Isolated segments of the proximal colon exhibit a high-amplitude phasic contractile activity that was increased by stretching, transiently inhibited by ATRO, unaffected by hexamethonium, and increased by TTX. The effects of both ATRO and TTX were more evident at high- than low-resting tone. In the presence of ATRO plus guanethidine, field stimulation of the isolated rat proximal colon suppressed the spontaneous contractile activity of the preparations. These findings indicate that, in the proximal colon of urethan-anesthetized rats, a tonic discharge of intramural nonadrenergic noncholinergic neurons suppresses the inherent myogenic contractile activity of the smooth muscle cells. Extrinsic nervous supply plays a subsidiary role in maintaining colonic motility.

Myoelectric properties of the cat ileocecal sphincter

1981 ◽  
Vol 240 (6) ◽  
pp. G450-G458 ◽  
Author(s):  
A. Ouyang ◽  
W. J. Snape ◽  
S. Cohen
Keyword(s):  
Action Potential ◽  
Mechanical Stimulation ◽  
Spike Activity ◽  
Castor Oil ◽  
Proximal Colon ◽  
Wave Activity ◽  
Tonic Contraction ◽  
Myoelectric Activity ◽  
Spike Potential ◽  
Sphincter Function

Myoelectric activity and intraluminal pressures were recorded simultaneously from the ileum, ileocecal sphincter (ICS), and proximal colon in chloralose-anesthetized cats. Slow-wave activity, seen at all areas, showed coupling of frequency in the distal ileum and ICS. ICS spike activity was both isolated and associated with ileal or colonic spike activity and correlated with phasic contractions (r = 0.86; P less than 0.01). Ileal distensions caused ICS relaxation and decreased spike activity 33.8% of the time. Colonic distensions caused contraction and increased spike activity 46.9% of the time. Migrating action-potential complexes (MAPC) induced by castor oil, ricinoleic acid, or cholecystokinin propagated to the ICS and through to the colon significantly more frequently than ileal non-MAPC (P less than 0.05). Both spike potential-dependent and spike potential-independent mechanisms were involved in ICS contraction. Bethanechol increased spike activity and phasic and tonic contractions. Phenylephrine, despite loss of spike activity in all leads, caused tonic contraction of the ICS. Isoproterenol caused loss of spike activity and decreased ICS pressure. Thus, ICS myoelectric activity appears to be important in determining sphincter function during neurohumoral and mechanical stimulation, with ICS contractions occurring through both a phasic spike-related mechanism and a tonic mechanism without spike activity.

Enteric Distribution of Oral Contrast in Emergency Department Patients Undergoing Abdominal-Pelvic Computed Tomography

2016 ◽  
Vol 67 (3) ◽  
pp. 204-211 ◽  
Author(s):  
Tarek N. Hanna ◽  
Drew A. Streicher ◽  
Seyed Amirhossein Razavi ◽  
Faisal Khosa ◽  
Jamlik-Omari Johnson ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Emergency Department ◽  
Terminal Ileum ◽  
Gastrointestinal Surgery ◽  
Distal Colon ◽  
Proximal Colon ◽  
Final Report ◽  
Oral Contrast ◽  
Continued Use ◽  
Emergency Department Patients

Purpose The study sought to assess the gastrointestinal (GI) distribution of oral contrast (OC) among emergency department (ED) patients and determine if contrast reaches the terminal ileum or site of pathology to assist in diagnosis. Methods Retrospectively, adults undergoing abdominal-pelvic computed tomography (APCT) in the ED at 2 hospitals were identified over a 3-month period. APCTs were reviewed for location of OC. Presence, site, type of bowel pathology, and prior gastrointestinal surgery were documented. When applicable, the site of bowel pathology was evaluated for the presence or absence of OC. Results There were 1349 exams with mean age 50.5 years (range 18–97 years), 41% male, with 530 (39%) receiving OC. In 271 of 530 (51%), OC reached the terminal ileum (TI). Bowel pathology was present in 31% of cases (165 of 530). When bowel pathology was present, 47% (77 of 165) had OC present at the pathology site. The GI tract was divided into 4 anatomic segments: OC most frequently reached pathology in stomach and duodenum (84%), but was present less frequently at sites of pathology from jejunum to TI (35%), proximal colon (57%), and distal colon (28%). In only 84 of 530 OC cases (16%) did contrast extend from the stomach to distal colon. OC administration contributed to longer mean APCT order to final report of 0.5 hours and longer mean ED length of stay of 0.8 hours compared with all patients who received APCT. Conclusions Optimal OC distribution is not achieved in more than half of ED patients, raising questions about the continued use of OC in the ED.

Sympathetic control of motility, fluid transport, and transmural potential difference in the rabbit ileum

1987 ◽  
Vol 253 (6) ◽  
pp. G726-G729 ◽  
Author(s):  
B. Greenwood ◽  
L. Tremblay ◽  
J. S. Davison
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Intestinal Motility ◽  
Fluid Transport ◽  
Contractile Activity ◽  
Electrolyte Transport ◽  
Potential Difference ◽  
Rabbit Ileum ◽  
Adrenoceptor Antagonist ◽  
Sympathetic Nervous

Both intestinal motility and intestinal fluid and electrolyte transport are influenced by the sympathetic nervous system. The aim of this study is to examine the relationship between the sympathetically induced inhibition of spontaneous contractile activity and epithelial function, monitoring simultaneously motility, fluid transport, and transmural potential difference (PD) in the rabbit ileum. Experiments were performed in vitro to eliminate any possible indirect effects on intestinal function caused by alterations in intestinal blood flow. Perivascular nerve stimulation induced an inhibition of spontaneous motility, a fall in transmural PD (toward more lumen positive), and an enhanced fluid absorption. The sympathetically induced inhibition of motility was abolished by the beta-adrenoceptor antagonist, propranolol, whereas the subsequent administration of phentolamine, the alpha-adrenoceptor antagonist, was required to abolish the fall in transmural PD. Thus the sympathetic nervous system is capable of simultaneously influencing intestinal motility and fluid and electrolyte function. However, separate but parallel neural mechanisms control the smooth muscle and epithelial responses; the inhibition of motility is beta-mediated, while alpha-receptors alter fluid and electrolyte transport.

Sign in / Sign up

Export Citation Format

Share Document