Transmission of electrical activity through the gastroduodenal junction

1965 ◽  
Vol 208 (3) ◽  
pp. 531-536 ◽  
Author(s):  
Alex Bortoff ◽  
Noah Weg
Keyword(s):  
Small Intestine ◽  
Electrical Activity ◽  
Longitudinal Muscle ◽  
Muscle Layer ◽  
Slow Waves ◽  
Pyloric Antrum ◽  
Longitudinal Muscle Layer ◽  
Proximal Duodenum ◽  
Electrical And Mechanical Activities ◽  
Electrode Technique

The electrical and mechanical activities of the gastroduodenal junction were studied in isolated cat preparations, using the pressure-electrode technique. The spontaneous electrical activity of the pyloric antrum consists of periodic depolarizations, the configuration of which is somewhat more complex than that of comparable potentials recorded from the longitudinal muscle layer of the small intestine. Like their intestinal counterparts these antral slow waves may be associated with spike potentials which are thought to initiate contractions. The electrical activity at the gastroduodenal junction consists of a combination of antral and duodenal slow waves, sometimes accompanied by spike potentials. In the proximal duodenum, antral slow waves are represented by periodic depolarizations which may be associated with spike potentials followed by contractions. Because of the extension of the antral slow waves into the proximal duodenum, contractions initiated in the antrum may also extend into the proximal duodenum. It is concluded that the gastroduodenal junction is a transition zone, coordinating the electrical and corresponding mechanical activities of the antrum and proximal duodenum.

Responses of muscles of cat small intestine to autonomic nerve stimulation

1963 ◽  
Vol 204 (2) ◽  
pp. 352-358 ◽  
Author(s):  
Gordon L. Van Harn
Keyword(s):  
Small Intestine ◽  
Muscle Contraction ◽  
Nerve Stimulation ◽  
Sympathetic Nerve ◽  
Longitudinal Muscle ◽  
Muscle Layer ◽  
Slow Waves ◽  
Intraluminal Pressure ◽  
Sympathetic Nerve Stimulation ◽  
Longitudinal Muscle Layer

The externally recorded slow waves from the cat small intestine originate in the longitudinal muscle layer. In vitro the slow waves are recorded from all layers of the intestine if the segment is not immersed in a saline bath. When the longitudinal layer is removed from one region, the magnitude of the slow-wave potential in the other intestinal layers decreases as the distance from the intact longitudinal muscle layer is increased. An active intestine, in vivo, responds to sympathetic nerve stimulation by a hyperpolarization, cessation of spikes, and inhibition of muscle contraction. During inactivity of the intestine, either vagus or sympathetic nerve stimulation results in a depolarization, initiation of spikes, and muscle contraction. The nature of the response is influenced by the frequency of nerve stimulation and by the level of activity of the intestinal muscle, which is altered by intraluminal pressure changes. The effect of drugs on the response of the intestine to vagal and sympathetic nerve stimulation is such as to indicate that both inhibitory and excitatory nerve fibers are present in each of the autonomic nerves. The duration of the latent period of the response is long and highly variable, and a response requires 50–100 nerve volleys.

Separation of enkephalin-degrading enzymes from longitudinal muscle layer of bovine small intestine

1985 ◽  
Vol 34 (17) ◽  
pp. 3179-3183 ◽  
Author(s):  
Tadahiko Hazato ◽  
Mariko Shimamura ◽  
Ryoichi Kase ◽  
Mikio Iijima ◽  
Takashi Katayama
Keyword(s):  
Small Intestine ◽  
Longitudinal Muscle ◽  
Muscle Layer ◽  
Longitudinal Muscle Layer ◽  
Degrading Enzymes ◽  
Bovine Small Intestine

Proteolytic Inactivation of Substance P and Neurokinin A in the Longitudinal Muscle Layer of Guinea Pig Small Intestine

2006 ◽  
Vol 47 (3) ◽  
pp. 856-864 ◽  
Author(s):  
R. Nau ◽  
G. Schäfer ◽  
C. F. Deacon ◽  
T. Cole ◽  
D. V. Agoston ◽  
...  
Keyword(s):  
Small Intestine ◽  
Substance P ◽  
Guinea Pig ◽  
Longitudinal Muscle ◽  
Muscle Layer ◽  
Neurokinin A ◽  
Longitudinal Muscle Layer

Longitudinal contractions in the duodenum: their fluid-mechanical function

1975 ◽  
Vol 228 (6) ◽  
pp. 1887-1892 ◽  
Author(s):  
J Melville ◽  
E Macagno ◽  
J Christensen
Keyword(s):  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Slow Waves ◽  
Longitudinal Muscle Layer ◽  
Circular Muscle Layer ◽  
Model Flow ◽  
Displacement Wave ◽  
Marked Points

The hypothesis examined was that contractions of the longitudinal muscle layer occurin the duodenum which are independent of those of the circular muscle layer and that they induce flow of duodenal contents. A segment of opossum duodenum isolated in vitro was marked and photographed during periods of longitudinal muscle contraction, when the circular muscle layer appeared inactive. The prequency of longitudinal oscillation of the marked points was 20.5 cycles/min. The longitudinal displacement wave spread caudad with an average velocity of 3.27 cm/s. Frequency and velocity of electrical slow waves were determined in similiar duodenal segments. Slow-wave frquencywas 18.9 cycles/min. In a two-dimensional mechanical model, flow induced by simulatedlongitudinal muscle layer appear to be driven by the electrical slow waves of the duodenum. They are capable of inducing a pattern of flow in which ocntents flow betweenthe core and the periphery of the intestinal conduit.

Electrical activity of the longitudinal muscle of dog small intestine studied in vivo using microelectrodes

1960 ◽  
Vol 198 (1) ◽  
pp. 113-118 ◽  
Author(s):  
E. E. Daniel ◽  
A. J. Honour ◽  
A. Bogoch
Keyword(s):  
Small Intestine ◽  
Body Temperature ◽  
Action Potential ◽  
Electrical Activity ◽  
Longitudinal Muscle ◽  
Muscle Cells ◽  
Slow Waves

The electrical activity of longitudinal muscle cells of the small intestine of the dog have been recorded in vivo using microelectrodes. This activity is characterized by periodic slow depolarizations of from 3 to 15 mv starting from potentials of 35–50 mv. The frequency of these slow depolarizations is less in the ileum than in the jejunum and is diminished by reduction in body temperature. Asphyxia diminishes both frequency and amplitude of these slow depolarizations without affecting the resting potentials. Action potential spikes arise from the larger slow depolarizations. The records obtained in this study are compared with previously recorded monopolar extracellular records. It is concluded that the slow waves recorded using extracellular electrodes arise from slow depolarizations of intestinal muscle cells. It is proposed that these slow depolarizations are a coordinating mechanism for motility of the longitudinal muscle of the dog intestine. The mechanism of synchronization of the slow waves themselves remains to be elucidated.

Dominance of longitudinal muscle in propagation of intestinal slow waves

1981 ◽  
Vol 240 (3) ◽  
pp. C135-C147 ◽  
Author(s):  
A. Bortoff ◽  
D. Michaels ◽  
P. Mistretta
Keyword(s):  
Slow Wave ◽  
Longitudinal Muscle ◽  
Contractile Activity ◽  
Circular Muscle ◽  
Active Role ◽  
Muscle Layer ◽  
Slow Waves ◽  
Longitudinal Muscle Layer ◽  
Intestinal Slow Waves ◽  
Mucosal Side

The purpose of these experiments was to test the hypothesis that circular muscle plays an active role in the propagation of intestinal slow waves, specifically be providing excitatory current through a process of regenerative amplification. With volume-recording techniques and microelectrode recordings we obtained the following results that are not consistent with such a mechanism: 1) slow waves propagated without delay or decrease in amplitude along segments of cat jejunum devoid of a ring of circular muscle up to 3 mm wide, i.e., across a longitudinal muscle bridge more than 4 space constants long (9 of 11 preparations) but did not propagate across a circumferential cut through the longitudinal muscle layer (14 of 14 preparations); 2) the membrane current associated with the slow wave had a pronounced inward component when recorded from either the serosal or the mucosal side of the longitudinal muscle bridge but was entirely outward when recorded from either the mucosal or the serosal side of exposed circular muscle, including those preparations in which various thicknesses of circular muscle were removed from the mucosal side of the recording area; 3) slow-wave amplitudes recorded intracellularly from intact (n = 9) and isolated (n = 8) longitudinal muscle preparations were not significantly different (27.0 +/- 4.3 vs. 25.4 +/- 5.3 (SD) mV); 4) after 30 min in 4.4 X 10(-6) M verapamil, slow-wave amplitude did not significantly decrease, although contractile activity had long since terminated. These results are more consistent with the hypothesis that longitudinal muscle provides most, if not all, of the current required for slow-wave propagation in the small intestine.

scholarly journals First reported case of per anal endoscopic myectomy (PAEM): A novel endoscopic technique for resection of lesions with severe fibrosis in the rectum

2017 ◽  
Vol 05 (03) ◽  
pp. E146-E150 ◽  
Author(s):  
David Rahni ◽  
Takashi Toyonaga ◽  
Yoshiko Ohara ◽  
Francesco Lombardo ◽  
Shinichi Baba ◽  
...  
Keyword(s):  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Rectal Tumor ◽  
Resection Margins ◽  
Submucosal Layer ◽  
Longitudinal Muscle Layer ◽  
Circular Muscle Layer ◽  
Tunneling Method ◽  
Severe Fibrosis

Background and study aims A 54-year-old man was diagnosed with a rectal tumor extending through the submucosal layer. The patient refused surgery and therefore endoscopic submucosal dissection (ESD) was pursued. The lesion exhibited the muscle retraction sign. After dissecting circumferentially around the fibrotic area by double tunneling method, a myotomy was performed through the internal circular muscle layer, creating a plane of dissection between the internal circular muscle layer and the external longitudinal muscle layer, and a myectomy was completed.The pathologic specimen verified T1b grade 1 sprouting adenocarcinoma with 4350 µm invasion into the submucosa with negative resection margins.

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