Site-specific gene expression of nNOS variants in distinct functional regions of rat gastrointestinal tract

2002 ◽  
Vol 282 (2) ◽  
pp. G349-G358 ◽  
Author(s):  
Dieter Saur ◽  
Winfried L. Neuhuber ◽  
Bernd Gengenbach ◽  
Andrea Huber ◽  
Volker Schusdziarra ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Specific Gene ◽  
Specific Expression ◽  
Gastric Stasis ◽  
Longitudinal Muscle Layer ◽  
Translational Initiation ◽  
Site Specific ◽  
Mrna Variants

5′ mRNA variants of neuronal nitric oxide synthase (nNOS) are generated either by alternative promoter usage resulting in different mRNAs that encode for the same protein (nNOSα) or alternative splicing encoding NH2-terminally truncated proteins (nNOSβ/γ) that lack the PDZ/GLGF domain for protein-protein interaction of nNOSα. We studied the expression of 5′ nNOS mRNA forms and nNOS-interacting proteins (postsynaptic density protein-95; PSD-95) in the rat gastrointestinal tract and analyzed the more distinct localization of nNOS protein variants in the duodenum by immunohistochemistry with COOH- and NH2-terminal nNOS antibodies. 5′ nNOS mRNA variants showed a site-specific expression along the gastrointestinal tract with presence of all forms (nNOSα-a, -b, -c; nNOSβ) in the muscle layer of esophagus, stomach, duodenum, longitudinal muscle layer of jejunum/ileum, proximal colon, and rectum. In contrast, a lack of nNOSα-a and nNOSβ mRNA was observed in pylorus, circular muscle layer of jejunum/ileum, and cecum. Expression of nNOSα and nNOSβ cDNAs revealed proteins of ∼155 kDa and 135/125 kDa, respectively. Immunohistochemistry showed a differential distribution of COOH- and NH2-terminal nNOS immunoreactivity in distinct layers of rat duodenum, suggesting a cell-specific expression and distinct compartmentalization of nNOS proteins. Observed distribution of 5′ nNOS mRNA variants and proteins argue for a complex control of nNOS expression by usage of separate promoters, cell- and site-specific splicing mechanisms, and translational initiation. These mechanisms could be involved in gastrointestinal motor diseases and may explain the phenotype of nNOSα knockout mice with gastric stasis and pyloric stenosis, due to a total loss of nNOS in the pyloric sphincter region.

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.

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

1998 ◽  
Vol 76 (10-11) ◽  
pp. 989-999 ◽  
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.

scholarly journals The Fine Structure of Some Blood Vessels of the Earthworm, Eisenia foetida

1960 ◽  
Vol 7 (4) ◽  
pp. 717-724 ◽  
Author(s):  
Kiyoshi Hama
Keyword(s):  
Fine Structure ◽  
Basement Membrane ◽  
Body Wall ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Eisenia Foetida ◽  
Longitudinal Muscle Layer ◽  
Cell Processes ◽  
Body Wall Musculature ◽  
Blood Pigment

The fine structure of the main dorsal and ventral circulatory trunks and of the subneural vessels and capillaries of the ventral nerve cord of the earthworm, Eisenia foetida, has been studied with the electron microscope. All of these vessels are lined internally by a continuous extracellular basement membrane varying in thickness (0.03 to 1 µ) with the vessel involved. The dorsal, ventral, and subneural vessels display inside this membrane scattered flattened macrophagic or leucocytic cells called amebocytes. These lie against the inner lining of the basement membrane, covering only a small fraction of its surface. They have long, attenuated branching cell processes. All of these vessels are lined with a continuous layer of unfenestrated endothelial cells displaying myofilaments and hence qualifying for the designation of "myoendothelial cells." The degree of muscular specialization varies over a spectrum, however, ranging from a delicate endowment of thin myofilaments in the capillary myoendothelial cells to highly specialized myoendothelial cells in the main pulsating dorsal blood trunk, which serves as the worm's "heart" or propulsive "aorta." The myoendothelial cells most specialized for contraction display well organized sarcoplasmic reticulum and myofibrils with thick and thin myofilaments resembling those of the earthworm body wall musculature. In the ventral circulatory trunk, circular and longitudinal myofilaments are found in each myoendothelial cell. In the dorsal trunk, the lining myoendothelial cells contain longitudinal myofilaments. Outside these cells are circular muscle cells. The lateral parts of the dorsal vessels have an additional outer longitudinal muscle layer. The blood plasma inside all of the vessels shows scattered particles representing the circulating earthworm blood pigment, erythrocruorin.

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

1990 ◽  
Vol 258 (3) ◽  
pp. G344-G351 ◽  
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.

scholarly journals A Qualitative and Quantitative Study on the Enkephalinergic Innervation of the Pig Gastrointestinal Tract

2000 ◽  
Vol 48 (3) ◽  
pp. 333-343 ◽  
Author(s):  
Christophe Porcher ◽  
Yvon Julé ◽  
Monique Henry
Keyword(s):  
Anal Sphincter ◽  
Neural Control ◽  
Circular Muscle ◽  
Distal Colon ◽  
Muscle Layer ◽  
Intestinal Wall ◽  
Nerve Fibers ◽  
Longitudinal Muscle Layer ◽  
Submucous Plexus ◽  
Qualitative And Quantitative

Enkephalins are involved in neural control of digestive functions such as motility, secretion, and absorption. To better understand their role in pigs, we analyzed the qualitative and quantitative distribution of enkephalin immunoreactivity (ENK-IR) in components of the intestinal wall from the esophagus to the anal sphincter. Immunohistochemical labelings were analyzed using conventional fluorescence and confocal microscopy. ENK-IR was compared with the synaptophysin immunoreactivity (SYN-IR). The results show that maximal ENK-IR levels in the entire digestive tract are reached in the myenteric plexuses and, to a lesser extent, in the external submucous plexus and the circular muscle layer. In the longitudinal muscle layer, ENK-IR was present in the esophagus, stomach, rectum, and anal sphincter, whereas it was absent from the duodenum to the distal colon. In the ENK-IR plexuses and muscle layers, more than 60% of the nerve fibers identified by SYN-IR expressed ENK-IR. No ENK-IR was observed in the internal submucous plexus and the mucosa; the latter was found to contain ENK-IR endocrine cells. These results strongly suggest that, in pigs, enkephalins play a major role in the regulatory mechanisms that underlie the neural control of digestive motility.

scholarly journals Rhythmic Electrical Activity in Stomach and Intestine of Toad

1980 ◽  
Vol 86 (1) ◽  
pp. 237-248
Author(s):  
ALLEN MANGEL ◽  
C. LADD PROSSER
Keyword(s):  
Smooth Muscle ◽  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Sodium Concentration ◽  
Muscle Layer ◽  
Free Solution ◽  
Longitudinal Muscle Layer ◽  
Longitudinal Smooth Muscle ◽  
Mammalian Intestine ◽  
Periodic Changes

The intact stomach of the toad initiates rhythmic slow-spikes of 5–15 s duration and frequency of 3-5 min−1. The spontaneous electrical waves originate in the longitudinal muscle layer; isolated circular muscle is quiescent. Aboral conduction velocity is 0.12–0.9 mm s−1. Reduction of external sodium concentration from 89.5 to 15 mM produced no effect on slow spikes, although further reduction to 1.5 mM increased frequency and decreased amplitude. Slow-spikes were unaffected by ouabain or by incubation in potassium-free solution. When calcium in the medium was reduced, slow-spike amplitude and frequency decreased. Slow-spikes exhibited a change in amplitude of 16 mV per decade change in CaO2+; slow-spikes were eliminated at 10−8 M CaO2+ and by blockers of calcium conductance channels. Intact intestine of toad demonstrated slow-waves which resembled those of mammalian intestine. These were sensitive to changes in external sodium and were eliminated by 1 × 10−4M ouabain. It is suggested that rhythmic slow-spikes of longitudinal smooth muscle of amphibian stomach may result from periodic changes in Ca conductance whereas endogenous electrical waves of intestine may result from rhythmic extrusion of sodium.

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.

scholarly journals Two Cases of Rectal Neuroendocrine Tumor Resection Combined with Dissection of the Circular Muscle Layer Using the Endoscopic Submucosal Dissection Technique

2016 ◽  
Vol 10 (3) ◽  
pp. 693-700 ◽  
Author(s):  
Kumpei Honjo ◽  
Kazumasa Kure ◽  
Ryosuke Ichikawa ◽  
Hisashi Ro ◽  
Rina Takahashi ◽  
...  
Keyword(s):  
Endoscopic Submucosal Dissection ◽  
Endoscopic Therapy ◽  
Tumor Resection ◽  
Circular Muscle ◽  
Muscle Layer ◽  
En Bloc ◽  
Lower Rectum ◽  
Longitudinal Muscle Layer ◽  
Circular Muscle Layer ◽  
Submucosal Dissection

Generally, lesions of rectal neuroendocrine tumors (NETs) 10 mm or smaller are less malignant and are indicated for endoscopic therapy. However, the vertical margin may remain positive after conventional endoscopic mucosal resection (EMR) because NETs develop in a way similar to submucosal tumors (SMTs). The usefulness of EMR with a ligation device, which is modified EMR, and endoscopic submucosal dissection (ESD) was reported, but no standard treatment has been established. We encountered 2 patients in whom rectal NETs were completely resected by combined dissection and resection of the circular muscle layer using the ESD technique. Case 1 was an 8-mm NET of the lower rectum. Case 2 was NET of the lower rectum treated with additional resection for a positive vertical margin after EMR. In both cases, the circular muscle layer was dissected applying the conventional ESD technique, followed by en bloc resection while conserving the longitudinal muscle layer. No problems occurred in the postoperative course in either case. Rectal NETs are observed in the lower rectum in many cases, and it is less likely that intestinal perforation by endoscopic therapy causes peritonitis. The method employed in these cases, namely combined dissection and resection of the circular muscle layer using the ESD technique, can be performed relatively safely, and it is possible to ensure negativity of the vertical margin. In addition, it may also be useful for additional treatment of cases with a positive vertical margin after EMR.

scholarly journals Cocaine and Amphetamine Regulated Transcript (CART) Expression Changes in the Stomach Wall Affected by Experimentally Induced Gastric Ulcerations

2021 ◽  
Vol 22 (14) ◽  
pp. 7437
Author(s):  
Michal Zalecki ◽  
Adrianna Plywacz ◽  
Hanna Antushevich ◽  
Amelia Franke-Radowiecka
Keyword(s):  
Gastrointestinal Tract ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Tissue Reaction ◽  
Gastric Ulceration ◽  
Stomach Wall ◽  
Gene Encoding ◽  
Ulcer Disease ◽  
Encoding Gene

Cocaine- and amphetamine-regulated transcript (CART) is a peptide suggested to play a role in gastrointestinal tract tissue reaction to pathology. Gastric ulceration is a common disorder affecting huge number of people, and additionally, it contributes to the loss of pig livestock production. Importantly, ulceration as a focal disruption affecting deeper layers of the stomach wall differs from other gastrointestinal pathologies and should be studied individually. The pig’s gastrointestinal tract, due to its many similarities to the human counterpart, provides a valuable experimental model for studying digestive system pathologies. To date, the role of CART in gastric ulceration and the expression of the gene encoding CART in porcine gastrointestinal tube are completely unknown. Therefore, we aimed to verify the changes in the CART expression by Q-PCR (gene encoding CART in the tissue) and double immunofluorescence staining combined with confocal microscopy (CART immunofluorescence in enteric nervous system) in the porcine stomach tissues adjacent to gastric ulcerations. Surprisingly, we found that gastric ulcer caused a significant decrease in the expression of CART-encoding gene and huge reduction in the percentage of CART-immunofluorescent myenteric perikarya and neuronal fibers located within the circular muscle layer. Our results indicate a unique CART-dependent gastric response to ulcer disease.

Structural characterization of interstitial cells of Cajal in myenteric plexus and muscle layers of canine colon

1990 ◽  
Vol 68 (11) ◽  
pp. 1419-1431 ◽  
Author(s):  
I. Berezin ◽  
J. D. Huizinga ◽  
E. E. Daniel
Keyword(s):  
Myenteric Plexus ◽  
Interstitial Cells Of Cajal ◽  
Longitudinal Muscle ◽  
Structural Characteristics ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Interstitial Cells ◽  
The Other ◽  
Longitudinal Muscle Layer ◽  
Cells Of Cajal

We have carried out a detailed ultrastructural study of the interstitial cells near the myenteric plexus of the canine colon and defined the structural characteristics which distinguish them from other resident non-neural cells. We have also examined the interconnections of these interstitial cells with nerves, the longitudinal muscle, and the circular muscle. In addition, we sought connections between interstitial cells of the myenteric plexus and those described earlier at the inner border of the circular muscle in proximal and distal colon. The interstitial cells of the myenteric plexus were structurally distinctive, and made gap junctions with one another and occasionally with smooth muscle. There seemed to be two subsets of these interstitial cells, one associated with the longitudinal muscle and the other with the circular muscle. Cells of both subsets were often close (≤20 nm) to nerve profiles. The interstitial cells near the longitudinal muscle layer penetrated slightly into the muscle layer, but those near the circular muscle did not and neither set contacted the other. Moveover, interstitial cells of Cajal located near the myenteric plexus were never observed to contact those at the inner border of circular muscle. The interstitial cells of Cajal at the canine colon myenteric plexus are structurally organized to provide independent pacemaking activities for the longitudinal and adjacent circular muscle. Their dense innervation suggests that they mediate neural modulation of intestinal pacemaker activities. Moreover, they lack direct contacts with the interstitial cell network at the inner border of circular muscle, which is essential for the primary pacemaking activity of circular muscle. The structural organization of interstitial cells in canine colon is consistent with their proposed role in pacemaking activity of the two muscle layers.Key words: pacemakers, neuromodulation, interstitial cells of Cajal.

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