Effect of toxigenic Escherichia coli on myoelectric activity of small intestine.

1978 ◽  
Vol 235 (3) ◽  
pp. E311 ◽  
Author(s):  
T W Burns ◽  
J R Mathias ◽  
G M Carlson ◽  
J L Martin ◽  
R P Shields

When exposed to cholera toxin (CT), distal ileal loops of the rabbit small intestine showed an alteration in myoelectric activity. This alteration was defined as the migrating action potential complex (MAPC). The purpose of this study was to determine, using myoelectric recording techniques, the effects of live toxigenic Escherichia coli (TEC) on motility. Live TEC, live nontoxigenic E. coli (NTEC), and culture filtrates of these organisms were studied. Live TEC and its filtrate induced MAPC activity similar to that of CT. Live TEC induced a mean of 3.8 MAPCs/h, significantly greater than induced by live NTEC. TEC filtrate induced a mean of 14.2 MAPCs/h, significantly greater than NTEC filtrate. Heating the TEC filtrate to 100 degrees C before use resulted in a significant decrease of MAPC activity. This experiment demonstrated that live TEC and its culture filtrate altered ileal myoelectric activity. The effect may have been mediated by a heat-labile enterotoxin. This study suggests that alterations in small intestinal motility may be important in the pathogenesis of TEC diarrhea.

1982 ◽  
Vol 242 (4) ◽  
pp. G360-G363 ◽  
Author(s):  
J. R. Mathias ◽  
J. Nogueira ◽  
J. L. Martin ◽  
G. M. Carlson ◽  
R. A. Giannella

Escherichia coli heat-stable enterotoxin is a low-molecular-weight substance that has been shown to induce the active secretion of fluid and electrolytes in the small intestine. In this study, we have characterized the effects of purified E. coli heat-stable toxin (ST, strain 18D, serotype 042:K86:H37) on the motility of rabbit small intestine by using myoelectric recording techniques. Substances, such as cholera toxin, that activate the adenylate cyclase-cAMP system induced predominantly migrating action-potential complex activity. E. coli ST, a toxin that activates the guanylate cyclase-cGMP system, was infused into isolated in vivo ileal loops of New Zealand White rabbits. Inactivated toxin was also studied by exposing the ST to 1 mM dithiothreitol for 90 min. Active E. coli ST induced only repetitive bursts of action potentials. When the toxin was inactivated with dithiothreitol, no alteration in myoelectric activity was observed. We speculate that repetitive bursts of action-potential activity may represent a virulent factor of the bacterium, altering motor activity to slow transit and allowing for bacterial proliferation and invasion.


2021 ◽  
Author(s):  
Masamichi Sato ◽  
Takahiro Kudo ◽  
Nobuyasu Arai ◽  
Reiko Kyodo ◽  
Kenji Hosoi ◽  
...  

Abstract Background: The correlation between small intestinal motility alteration and irritable bowel syndrome (IBS) is not well evaluated. Aims: To assess the small intestinal and colonic transits in an IBS rat model with restraint stress and determine the role of small intestinal motility in the IBS pathophysiology.Methods: Restraint stress was utilized to make adolescent IBS rat models that were evaluated for clinical symptoms, including stool frequency and diarrhea. The small intestinal motility and transit rate were also evaluated. The amounts of mRNA encoding corticotropin-releasing hormone, mast cell, and serotonin (5-Hydroxytryptamine; 5-HT) receptor 3a were quantified using real-time polymerase chain reaction (PCR); the 5-HT expression was evaluated using immunostaining.Results: Restraint stress significantly increased the number of fecal pellet outputs, stool water content, and small intestinal motility in the IBS rat models. There was no difference in real-time PCR results, but immunostaining analysis revealed that 5-HT expression in the small intestine was significantly increased in the IBS rat models.Conclusions: In the adolescent rat model of IBS with restraint stress, we observed an increase in small intestinal and colonic motility. In the small intestine, enhanced 5-HT secretion in the distal portion may be involved in increasing the small intestinal motility.


1980 ◽  
Vol 238 (1) ◽  
pp. G57-G62
Author(s):  
T. W. Burns ◽  
J. R. Mathias ◽  
J. L. Martin ◽  
G. M. Carlson ◽  
R. P. Shields

Invasive strains of Escherichia coli (4608-58 and TD 213 CL) altered myoelectric activity of the small intestine in New Zealand White rabbits. The altered myoelectric activity had two distinct complex patterns. The first was defined as repetitive bursts of action potentials (RBAPs) that occurred predominantly in infected ligated ileal loops. The RBAP activity is characterized by action potential discharge activity greater than 1.5 s in duration and occurring on three or more successive slow waves on the same electrode recording site. These bursts of action potentials often migrated to adjacent electrode sites. The second complex pattern, defined as the migrating action potential complex (MAPC), occurred predominantly in the uninfected small intestine orad to the ligated ileal loop. The MAPC consists of action potential discharge activity of 2.5 s or longer that propagates aborally over at least two consecutive electrode sites. These studies demonstrated an altered myoelectric pattern, the RBAP, characteristic of invasion within the infected ligated loop. The MAPC, characteristic of noninvasion, was noted in the uninfected proximal small intestine.


1998 ◽  
Vol 94 (6) ◽  
pp. 663-670 ◽  
Author(s):  
Mikael Lördal ◽  
Håkan Wallén ◽  
Paul Hjemdahl ◽  
Olof Beck ◽  
Per M. Hellström

1. The influence of circulating 5-hydroxytryptamine (serotonin) on small intestinal motility was investigated in healthy volunteers. 2. Small intestinal motility was studied by means of a constantly perfused multi-channel manometry tube, connected to a computer system. 3. Intravenous infusions of either 5-hydroxytryptamine at increasing doses or saline were given over a period of 4 h. 4. 5-Hydroxytryptamine infusion dose-dependently increased plasma 5-hydroxytryptamine from approximately 2 to 10 and 25 nmol/l respectively, as well as urinary excretions of 5-hydroxytryptamine and 5-hydroxyindole acetic acid, a major 5-hydroxytryptamine metabolite. 5. The number of phase III of the migrating motor complex originating in the small intestine was dose-dependently increased by 5-hydroxytryptamine, and found to correlate to the plasma concentration of 5-hydroxytryptamine. The fraction of phase III also increased at the expense of phase II activity. In addition, 5-hydroxytryptamine increased the motility index, propagation velocity of phase III activity and the amplitude of contractions during phase III. 6. Whereas the low dose of 5-hydroxytryptamine (15 nmol · min−1 · kg−1) had no haemodynamic effects, an increase in heart rate by approximately 20 beats/min, without change in blood pressure, was observed at the higher dose (60 nmol · min−1 · kg−1). Respiratory parameters did not change during infusion of 5-hydroxytryptamine at either dose. 7. In conclusion, elevation of circulating 5-hydroxytryptamine by intravenous infusion results in more frequent and faster propagating migrating motor complexes in the human small intestine during the interdigestive period.


2001 ◽  
Vol 280 (3) ◽  
pp. G368-G380 ◽  
Author(s):  
Einar Husebye ◽  
Per M. Hellström ◽  
Frank Sundler ◽  
Jie Chen ◽  
Tore Midtvedt

The effect of an intestinal microflora consisting of selected microbial species on myoelectric activity of small intestine was studied using germ-free rat models, with recording before and after specific intestinal colonization, in the unanesthetized state. Intestinal transit, neuropeptides in blood (RIA), and neuromessengers in the intestinal wall were determined. Clostridium tabificum vp 04 promoted regular spike burst activity, shown by a reduction of the migrating myoelectric complex (MMC) period from 30.5 ± 3.9 min in the germ-free state to 21.2 ± 0.14 min ( P < 0.01). Lactobacillus acidophilus A10 and Bifidobacterium bifidum B11 reduced the MMC period from 27.9 ± 4.5 to 21.5 ± 2.1 min ( P < 0.02) and accelerated small intestinal transit ( P < 0.05). Micrococcus luteus showed an inhibitory effect, with an MMC period of 35.9 ± 9.3 min compared with 27.7 ± 6.3 min in germ-free rats ( P < 0.01). Inhibition was indicated also for Escherichia coli X7gnotobiotic rats. No consistent changes in slow wave frequency were observed. The concentration of neuropeptide Y in blood decreased after introduction of conventional intestinal microflora, suggesting reduced inhibitory control. Intestinal bacteria promote or suppress the initiation and aboral migration of the MMC depending on the species involved. Bacteria with primitive fermenting metabolism (anaerobes) emerge as important promoters of regular spike burst activity in small intestine.


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