Electrical basis of contractions in the muscle layers of the pig colon

Huizinga, Jan D.; Diamant, NE; El-Sharkawy, T. Y.

doi:10.1152/ajpgi.1983.245.4.g482

Cited by 23 publications

(25 citation statements)

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“…A 5-cm segment of proximal small intestine with the pylorus attached was excised and pinned without tension on the bottom of a 5-ml water-jacket bath coated with Sylgard (Dow Corning, Midland, MI) at 37 Ϯ 0.5°C and bathed at 2 ml/min with warmed modified Krebs solution (in mM: 125 NaCl, 5 KCl, 2.5 CaCl2, 1.2 MgCl2, 1.2 NaH 2PO4, 4 NaHCO3, 11 glucose, and 10 HEPES) aerated with 95% O 2-5% CO2. Slow-wave activity was recorded with a serosal Ag/AgCl suction electrode (6,10,16,33) 2 cm distal to the pylorus for a minimum of 15 min. The electric signal was amplified on a Duo 773 electrometer (World Precision Instruments, Sarasota, FL) and digitalized on a PC with an Acknowledge-MP100 Biopac system (World Precision Instruments).…”

Section: Animalsmentioning

confidence: 99%

Accelerated intestinal transit in inbred mice with an increased number of interstitial cells of Cajal

Bellier¹,

Silva²,

Aubin-Houzelstein³

et al. 2005

American Journal of Physiology-Gastrointestinal and Liver Physi

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The interstitial cells of Cajal (ICC) play an important role in coordinating intestinal motility, and structural alterations in ICC are found in several human digestive diseases. Mouse models with defects in ICC allow a better understanding of their functions. We investigated the pattern of intestinal motility and the distribution of ICC in the PRM/Alf inbred mouse strain, characterized by a selective intestinal lengthening. In PRM/Alf mice, the digestive transit time, evaluated by using thermophilic Bacillus subtilis spores, was normal, indicating accelerated transit. The contractility and slow-wave frequency, recorded on isolated segments from the proximal small intestine, were significantly increased. The number of ICC was also significantly higher along the small intestine and the colon. The concomitant increase of the contractility, the slow-wave frequency, and the number of ICC is consistent with the proposal of a role of ICC number increase in the higher intestinal transit speed. The PRM/Alf model should be useful to further investigate the roles of ICC in the control of digestive motility. gut length; kit receptor; electrical slow waves; gastrointestinal motility; genetic model INTRINSIC AND EXTRINSIC NEUROHUMORAL signals control intestinal motility. An essential part of the system is the electrical pacemaker activity that originates in interstitial cells of Cajal (ICC). These cells are present in close association with smooth muscle cells and neurons of the gastrointestinal tract. In the mouse, ICC are fully differentiated at weaning, when the animals are given adult diet (13). The possible role of ICC in coordinating the contractile activity of the intestine has come to light in recent years (17,38). Alterations of ICC were reported in a variety of gastrointestinal disorders, including hypertrophic pyloric stenosis (24, 35, 41), Hirschsprung's disease (37,42,43), and intestinal pseudo-obstructions (19,21,44). Study of mouse models has proven to be a valuable strategy for studying the cause-and-effect relationship between ICC and motility problems, and Kit/W and SCF/Steel mutant mice have been instrumental in the study of the physiological roles of ICC (reviewed in Ref. 30). The Kit signaling pathway is essential for the development and maintenance of ICC (26). Both Kit and Steel mutant mice exhibit absence of electrical rhythmicity (i.e., slow waves) associated with underdevelopment of certain classes of ICC, including ICC of the small intestine that lie in the plane of the myenteric plexus (ICC-MP) between the circular and longitudinal muscle layers (17,38,39). The absence of ICC and slow waves in the small intestine of Kit mutant mice was paralleled with altered peristaltic movements of intestinal contents (10). However, it remains difficult to predict how abnormalities in ICC could influence digestive motor activity in vivo, because peristalsis is controlled by multiple, simultaneously operating mechanisms, in particular within the enteric nervous system (34). Indeed, migrating motor complexes can b...

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Section: Animalsmentioning

confidence: 99%

Accelerated intestinal transit in inbred mice with an increased number of interstitial cells of Cajal

Bellier¹,

Silva²,

Aubin-Houzelstein³

et al. 2005

American Journal of Physiology-Gastrointestinal and Liver Physi

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“…Between species the frequency of slow waves shows some variation; for example in the dog the frequency is about 5 cycles min-' (El-Sharkawy, 1983;Smith et al 1987 a, b) whereas in the pig the frequency is 0-5-3 5 cycles min-' (Huizinga et al 1983. Action potentials may or may not accompany the slow waves.…”

Section: Introductionmentioning

confidence: 99%

“…In colonic longitudinal muscle of several species including the guinea-pig, dog, pig and human, the.application of stretch appears to promote the onset of membrane potential oscillations. The onset of oscillatory activity appears to be controlled by both myogenic and neurogenic mechanisms (Biilbring, 1955;Gillespie, 1962;El-Sharkawy, 1983;Huizinga, Diamant & El-Sharkawy, 1983;Huizinga, Stern, Chow, Diamant & El-Sharkawy, 1985;Huizinga, Chow, Diamant & El-Sharkawy, 1987;Smith et al 1987 a).…”

Section: Introductionmentioning

confidence: 99%

Neurogenic slow depolarizations and rapid oscillations in the membrane potential of circular muscle of mouse colon.

Bywater

Small

Taylor

1989

The Journal of Physiology

136

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SUMMARY1. Intracellular microelectrodes have been used to record the electrical activity of smooth muscle cells of the circular layer from full length strips of mouse colon in vitro. The membrane potential was unstable and showed slow depolarizations (mean amplitude, 10-9 mV; mean frequency, 0-008 Hz; mean duration, 56-4 s).2. A variable number (mean fifty-six) of rapid oscillations in membrane potential (mean amplitude, 10-2 mV) with a frequency of approximately 2 Hz and a duration of approximately 400 ms were superimposed on each slow depolarization. Occasionally, action potentials arose from the rapid oscillations. The action potentials, but neither the slow depolarizations nor the rapid oscillations, were abolished by 1.0 utM-nifedipine.3. The majority of the slow depolarizations and the associated rapid oscillations migrated aborally along the colon at a velocity of between 0 5 and 1.5 mm s-1; in the distal colon the slow depolarization was often preceded by a small hyperpolarization.4. During the rising and plateau phase of the slow depolarization the amplitude of electrotonic potentials was decreased. Hyperpolarization induced by passing current during the slow depolarization increased the amplitude of the rapid oscillations.5. Transmural electrical stimulation (single pulses) in the presence of nifedipine evoked (1 mm anal to the stimulating electrodes) an inhibitory junction potential which was sometimes preceded by an excitatory junction potential. The amplitude. of the evoked inhibitory junction potential was decreased during the rising and plateau phase of the slow depolarization.6. The slow depolarization and the rapid oscillations were abolished by hexamethonium (500 /SM), morphine (1-10 /lM) and tetrodotoxin (3-1 /tM). Atropine 7. Atropine (3-5 /tM) and morphine (10 ,M) abolished the evoked excitatory junction potential whilst tetrodotoxin (3-1 /iM) abolished both the excitatory and the inhibitory junction potential.

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“…Unlike the small bowel and stomach, the longitudinal and circular muscles of the colon exhibit different electrical activities (Christensen et al 1969;El-Sharkawy, 1983;Huizinga et al 1983). Circular muscle generates slow wave activity as described above, whereas longitudinal muscles of the dog and pig colon generate pre-potentials and action potentials that are not associated with slow waves but appear to be dependent on external stimuli such as stretch or acetylcholine (El-Sharkawy, 1983;Huizinga et al 1983). Christensen et al (1969) reported that the duration of spontaneous slow waves of the circular muscle of the cat colon in vitro was variable (3-19 s).…”

Section: Introductionmentioning

confidence: 99%

Enteric neural regulation of slow waves in circular muscle of the canine proximal colon.

Sanders¹,

Smith²

1986

The Journal of Physiology

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SUMMARY1. The spontaneous electrical activities of circular muscle cells of the canine proximal colon were studied with intracellular micro-electrodes.2. All circular muscle cells exhibited slow waves at frequencies ranging between 2-8 and 7 0 cycles/min. The slow waves consisted of an upstroke phase followed by a plateau phase of variable duration (2-40 s). Many cells displayed a slow diastolic depolarization, or 'pre-potential' between slow waves.3. Slow waves spontaneously varied in duration and frequency in most preparations, creating distinctive slow wave patterns. Atropine, 2 x 10-6 M, decreased the durations of slow waves in many preparations and often changed the pattern to a series of relatively uniform slow waves. A further reduction in mean slow wave duration was produced by additional treatment with tetrodotoxin, 10-6 M. These results suggested that slow wave duration and pattern were affected by spontaneous discharge from both cholinergic and non-cholinergic excitatory nerves. 4. Transmural nerve stimulation caused a short latency increase in slow wave duration (up to 38 s) that was abolished by atropine. In the presence of atropine, transmural stimulation evoked inhibitory junction potentials that reduced the amplitude and duration of the subsequent slow wave. The slow wave of reduced amplitude was followed by a slow wave of increased duration. The increase in duration of the slow wave did not appear to be related to the size of the preceding hyperpolarization, suggesting it was mediated by the release from non-cholinergic excitatory nerves. All responses to transmural stimulation were blocked by tetrodotoxin.

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Electrical basis of contractions in the muscle layers of the pig colon

Cited by 23 publications

References 0 publications

Accelerated intestinal transit in inbred mice with an increased number of interstitial cells of Cajal

Accelerated intestinal transit in inbred mice with an increased number of interstitial cells of Cajal

Neurogenic slow depolarizations and rapid oscillations in the membrane potential of circular muscle of mouse colon.

Enteric neural regulation of slow waves in circular muscle of the canine proximal colon.

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