Histogenesis of the rostellum of Taenia crassiceps (Zeder, 1800) (Cestoda), with special reference to hook development

Histogenesis of the rostellum of Taenia crassiceps is described. The syncytial tegument and various cells take an active part in this differentiation. The increase in number of these cells as well as nuclei associated with the tegument, and changes in their relationship with one another, dominate the process. A specialized portion of the tegument termed the "hook organ" and its function in rostellar hook formation is considered. Rostellar hooks are produced de novo and not from fused microtriches as stated by some. When the hook organ is most active it is not separated from the underlying tissues by the subtegumental circular and longitudinal muscle layer as is the tegument of the adjacent bladder wall. When the rostellar hooks are fully differentiated the hook organ becomes an inner and outer ring of receptacles each with its own hook.

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

Endoscopy International Open ◽

10.1055/s-0042-122965 ◽

2017 ◽

Vol 05 (03) ◽

pp. E146-E150 ◽

Cited By ~ 1

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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Sodium nitrite, a potent relaxant of rat stomach fundus: in vitro evidence

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y98-107 ◽

1998 ◽

Vol 76 (10-11) ◽

pp. 989-999 ◽

Cited By ~ 2

Author(s):

Michal Ceregrzyn ◽

Tsuyoshi Ozaki ◽

Atsukazu Kuwahara ◽

Maria Wiechetek

Keyword(s):

Methylene Blue ◽

Potassium Channels ◽

Guanylate Cyclase ◽

Sodium Nitrite ◽

Longitudinal Muscle ◽

Circular Muscle ◽

Muscle Layer ◽

Rat Stomach ◽

Longitudinal Muscle Layer ◽

Stomach Fundus

The effects of sodium nitrite (0.1, 1, 10 mM) on mechanical activity of isolated rat stomach fundus muscle and the influence of guanylate cyclase activity inhibitor (methylene blue) and channel inhibitors (tetrodotoxin, charybdotoxin, apamin) were studied. Nitrite evoked dose-dependent relaxation in the longitudinal and circular muscle layers. The lowest effective concentration of sodium nitrite was 0.1 mM, which is comparable with the NOAEL (no observed adverse effect level). Tetrodotoxin (1 µM) markedly inhibited electrically induced contraction and rebound relaxation, but did not influence the nitrite-induced relaxation. Charybdotoxin (100 nM) decreased the relaxation evoked by 10 mM nitrite to 52.3 and 65.7% of control reaction in the circular and longitudinal muscle layer, respectively. Apamin (100 nM) did not influence the nitrite-induced relaxation. Methylene blue (10 µM) decreased relaxation induced by nitrite in the longitudinal and circular muscle layer, respectively, to 66.7 and 54.3% of the response to 1 mM nitrite alone. Relaxation induced by nitrite was decreased in the presence of L-cysteine (5 mM), and in the circular and longitudinal muscle layer reached 29.6 and 23.1%, respectively, of the response to 1 mM nitrite alone. We conclude that the relaxing effect of nitrite on gastric fundus results from its direct action on smooth muscle cells and probably the enteric nervous system is not involved in this action. The nitrite-elicited relaxation depends on activation of guanylate cyclase and high conductance Ca2+-activated potassium channels; however, activation of potassium channels might be a part of or might act in parallel with the mechanism involving the cyclic GMP system. Effects of nitrite observed in the presence of L-cysteine suggest that nitrosothiols are not responsible for nitrite-evoked activation of guanylate cyclase.Key words: nitrite, gastric motility, tetrodotoxin, methylene blue, charybdotoxin, L-cysteine.

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Membrane currents recorded from a fragment of rabbit intestinal smooth muscle cell

AJP Cell Physiology ◽

10.1152/ajpcell.1986.251.3.c335 ◽

1986 ◽

Vol 251 (3) ◽

pp. C335-C346 ◽

Cited By ~ 63

Author(s):

Y. Ohya ◽

K. Terada ◽

K. Kitamura ◽

H. Kuriyama

Keyword(s):

Smooth Muscle ◽

Longitudinal Muscle ◽

Outward Current ◽

Ionic Currents ◽

Muscle Layer ◽

Dependent Manner ◽

Rabbit Ileum ◽

Longitudinal Muscle Layer ◽

Inward Current ◽

K Currents

Properties of ionic currents in smooth muscle membranes of the longitudinal muscle layer of the rabbit ileum were investigated using the single electrode voltage clamp method. In the present experiments, this method was applicable only to the smooth muscle ball (fragment) and not for the dispersed whole cell, because of incompleteness of the voltage clamping. A voltage step elicited a transient inward current followed by an outward current. This outward current was partly inhibited by Mn2+ or nisoldipine or by a reduction in the extracellular [Ca2+] ([Ca2+]o). Tetraethylammonium (TEA) reduced the delayed outward current in a dose-dependent manner, but 50 mM TEA did not produce a complete block of a residual current. When the pipette contained K+-free (Cs+ with TEA+) solution, the residual outward current was abolished. The inward current was elicited at -30 mV (holding potential of -60 mV) and reached the maximal value at +10 mV; the polarity was reversed at +60 mV. This inward current depended on the [Ca2+]o and was blocked by Mn2+ or nisoldipine. Ba2+ also permeated the membrane, and the inward current evoked by Ba2+ was also blocked by Mn2+ or nisoldipine. Reduction of [Na+]o in a solution containing 2.4 mM Ca2+ neither modified the current-voltage relation nor the decay of the inward current, but when [Ca2+]o was reduced to below 1 microM, Na+ permeated the membrane and was blocked by nisoldipine. In conclusion, ionic currents were recordable from the fragmented ball of the longitudinal muscle of rabbit ileum. There were at least two K+ currents as the outward current (Ca2+-dependent K+ and delayed K+ currents) and a Ca2+ current as the inward current. The property of the Ca2+ channel was similar to that observed with other preparations.

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

Biochemical Pharmacology ◽

10.1016/0006-2952(85)90166-2 ◽

1985 ◽

Vol 34 (17) ◽

pp. 3179-3183 ◽

Cited By ~ 6

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

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In vitro microelectrode study of the electrical properties of smooth muscle in equine ileum

Veterinary Record ◽

10.1136/vr.149.23.707 ◽

2001 ◽

Vol 149 (23) ◽

pp. 707-711 ◽

Cited By ~ 10

Author(s):

N. P. H. Hudson ◽

I. G. Mayhew ◽

G. T. Pearson

Keyword(s):

Smooth Muscle ◽

Membrane Potential ◽

Smooth Muscle Cells ◽

Longitudinal Muscle ◽

Muscle Cells ◽

Muscle Layer ◽

Potential Oscillations ◽

Longitudinal Muscle Layer ◽

Membrane Potential Oscillations

Intracellular microelectrode recordings were made from smooth muscle cells in cross-sectional preparations of equine ileum, superfused in vitro. Membrane potential oscillations and spike potentials were recorded in all preparations, but recordings were made more readily from cells in the longitudinal muscle layer than from cells in the circular layer. The mean (se) resting membrane potential (RMP) of smooth muscle cells in the longitudinal muscle layer was -51.9 (1.2) mV, and the membrane potential oscillations in this layer had a mean amplitude of 4.8 (0.4) mV, a frequency of 9.0 (0.1) cycles per minute and a duration of 5.8 (0.2) seconds. The membrane potential oscillations were preserved in the presence of tetrodotoxin. A waxing and waning pattern of membrane potential oscillation activity was observed. Nifedipine abolished the spiking contractile activity of the smooth muscle, did not abolish the membrane potential oscillations but did alter their temporal characteristics.

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Responses of muscles of cat small intestine to autonomic nerve stimulation

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1963.204.2.352 ◽

1963 ◽

Vol 204 (2) ◽

pp. 352-358 ◽

Cited By ~ 19

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.

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Effects of transmural field stimulation in isolated muscle strips from human esophagus

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1990.258.3.g344 ◽

1990 ◽

Vol 258 (3) ◽

pp. G344-G351 ◽

Cited By ~ 3

Author(s):

A. Tottrup ◽

A. Forman ◽

P. Funch-Jensen ◽

U. Raundahl ◽

K. E. Andersson

Keyword(s):

Longitudinal Muscle ◽

Circular Muscle ◽

Muscle Layer ◽

Isometric Tension ◽

Field Stimulation ◽

Platinum Electrodes ◽

Longitudinal Muscle Layer ◽

Circular Muscle Layer ◽

Human Esophagus ◽

40 Hz

Smooth muscle strips representing longitudinal and circular muscle layers of the esophagogastric junction (EGJ) and esophageal body (EB) of the human esophagus were prepared. The strips were mounted in organ baths and isometric tension was recorded. Square wave stimulation was applied through platinum electrodes. Only responses abolished by tetrodotoxin (TTX) were considered neurogenic. Strips taken from longitudinal muscle layers of the EB and EGJ contracted during field stimulation. The responses evoked were abolished by atropine, and optimal frequency of stimulation was 40 Hz. In strips taken from the circular muscle layer of the EB, a contraction occurred after cessation of the stimulus. Atropine inhibited 90% of this response; the optimal stimulation frequency was 40 Hz. When a tone was induced in strips from this layer, a TTX-sensitive relaxation was seen during field stimulation. During stimulation of strips from the EGJ circular muscle layer, which was the only preparation developing spontaneous active tone, a relaxation was seen. A small contraction followed after termination of the stimulus. The relaxation, which was nonadrenergic, noncholinergic, reached maximum at 10 Hz. Atropine inhibited 40% of the contraction. The results suggest that in the longitudinal muscle layer of the human lower esophagus field stimulation causes postganglionic nerves to release transmitter(s) acting on muscarinic receptors. The responses of circular muscle layers seem to be mediated through release of at least two transmitters.

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Variability in the muscle composition of rat esophagus and neural pathway of lower esophageal sphincter relaxation

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00273.2011 ◽

2011 ◽

Vol 301 (6) ◽

pp. G1014-G1019 ◽

Cited By ~ 3

Author(s):

Yanfen Jiang ◽

Valmik Bhargava ◽

Harshal A. Lal ◽

Ravinder K. Mittal

Keyword(s):

Skeletal Muscle ◽

Smooth Muscle ◽

Vagus Nerve ◽

Longitudinal Muscle ◽

Muscle Layer ◽

Axial Stretch ◽

Longitudinal Muscle Layer ◽

Esophageal Sphincter ◽

Group 2 ◽

Group 1

Several studies from our laboratory show that axial stretch of the lower esophageal sphincter (LES) in an oral direction causes neurally mediated LES relaxation. Under physiological conditions, axial stretch of the LES is caused by longitudinal muscle contraction (LMC) of the esophagus. Because longitudinal muscle is composed of skeletal muscle in mice, vagal-induced LMC and LES relaxation are both blocked by pancuronium. We conducted studies in rats (thought to have skeletal muscle esophagus) to determine if vagus nerve-mediated LES relaxation is also blocked by pancuronium. LMC-mediated axial stretch on the LES was monitored using piezoelectric crystals. LES and esophageal pressures were monitored with a 2.5-Fr solid-state pressure transducer catheter. Following bilateral cervical vagotomy, the vagus nerve was stimulated electrically. LES, along with the esophagus, was harvested after in vivo experiments and immunostained for smooth muscle (smooth muscle α-actin) and skeletal muscle (fast myosin heavy chain). Vagus nerve-stimulated LES relaxation and esophageal LMC were reduced in a dose-dependent fashion and completely abolished by pancuronium (96 μg/kg) in six rats ( group 1). On the other hand, in seven rats, LES relaxation and LMC were only blocked completely by a combination of pancuronium ( group 2) and hexamethonium. Immunostaining revealed that the longitudinal muscle layer was composed of predominantly skeletal muscle in the group 1 rats. On the other hand, the longitudinal muscle layer of group 2 rats contained a significant amount of smooth muscle ( P < 0.05). Our study shows tight coupling between axial stretch on the LES and relaxation of the LES, which suggests a cause and effect relationship between the two. We propose that the vagus nerve fibers that cause LMC induce LES relaxation through the stretch-sensitive activation of inhibitory motor neurons.

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