Biochemical and Cytochemical Characterization of Extracellular Proteoglycans in the Inner Circular Smooth Muscle Layer of Dog Small Intestine

Background Ureteral peristalsis is the result of coordinated mechanical motor performance of longitudinal and circular smooth muscle layer of the ureter wall. The main aim of this study was to characterize in smooth muscle of proximal segments of human ureter, the mechanical properties at level of muscle tissue and at level of myosin molecular motors. Methods Ureteral samples were collected from 15 patients, who underwent nephrectomy for renal cancer. Smooth muscle strips longitudinally and circularly oriented from proximal segments of human ureter were used for the in vitro experiments. Mechanical indices including the maximum unloaded shortening velocity (Vmax), and the maximum isometric tension (P0) normalized per cross-sectional area, were determined in vitro determined in electrically evoked contractions of longitudinal and circular smooth muscle strips. Myosin cross-bridge (CB) number per mm2 (Ψ) the elementary force per single CB (Ψ) and kinetic parameters were calculated in muscle strips, using Huxley's equations adapted to nonsarcomeric muscles. Results Longitudinal smooth muscle strips exhibited a significantly (p<0.05) faster Vmax (63%) and a higher P0 (40%), if compared to circular strips. Moreover, longitudinal muscle strips showed a significantly higher unitary force (Ψ) per CB. However, no significant differences were observed in CB number, the attachment (f1) and the detachment (g2) rate constants between longitudinal and circular muscle strips. Conclusions The main result obtained in the present work documents that the mechanical, energetic and unitary forces per CB of longitudinal layer of proximal ureter are better compared to the circular one; these preliminary findings suggested, unlike intestinal smooth muscle, a major role of longitudinal smooth muscle layer in the ureter peristalsis.

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Expression of corticotropin releasing factor (CRF) in the enteric nervous system of the jejunum of sheep

Veterinární Medicína ◽

10.17221/4274-vetmed ◽

2011 ◽

Vol 56 (No. 11) ◽

pp. 551-560 ◽

Cited By ~ 1

Author(s):

A. Czujkowska ◽

MB Arciszewski

Keyword(s):

Nervous System ◽

Smooth Muscle ◽

Muscle Layer ◽

Corticotropin Releasing Factor ◽

Enteric Neurons ◽

Nerve Fibres ◽

Myenteric Neurons ◽

Smooth Muscle Layer ◽

Circular Smooth Muscle ◽

A Minor

 Corticotropin releasing factor (CRF), a 41-amino acid neuropeptide widely distributed in the mammalian central nervous system, has been shown to influence several gastrointestinal functions. Recent studies show that CRF released locally from enteric nerves may also underlie alterations in gut function. In this study, immunohistochemisty was applied to demonstrate the presence of CRF in the jejunum of sheep. Using double immunohistochemical staining the co-localization of CRF with vasoactive intestinal peptide (VIP), galanin, tyrosine hydroxylase (TH), neuropeptide Y (NPY) and substance P (SP) was evaluated. The presence of CRF was detected in myenteric neurons (3.6 ± 0.9%) as well as in submucous neurons (10.5 ± 1.2%). In the ovine jejunum different numbers of CRF-expressing nerve fibres were detected in myenteric ganglia, submucous ganglia, circular smooth muscle layer, lamina muscularis mucosae and between mucosal glands. None of the CRF-positive enteric neurons and CRF-positive nerve fibres exhibited the presence of TH. CRF-immunoreactive (IR) myenteric neurons widely co-expressed VIP and/or NPY. A minor population of CRF-IR myenteric neurons additionally co-stored SP. Galanin was not present in CRF-IR myenteric neurons. The presence of VIP was observed in the vast majority of CRF-positive submucous neurons. Moderate numbers of CRF-IR sumbucous neurons co-expressing galanin or NPY were also found. The presence of SP in CRF-positive submucous neurons was noted only incidentally. In the circular smooth muscle layer CRF-IR/VIP-IR, CRF-IR/NPY-IR as well as CRF-IR/SP-IR nerve fibres were present. In the mucosal layer of the ovine jejunum CRF-IR nerve fibres co-stored additionally VIP, galanin, NPY or SP. This present study provides for the first time evidence that CRF present in different subclasses of enteric neurons may influence certain activities of the ovine jejunum. Co-localization studies indicate that VIP, galanin, SP and NPY functionally co-operate with CRF in the jejunum of the sheep.  

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Lack of the complete circular rhabdosphincter and a distinct circular smooth muscle layer around the proximal urethra in elderly Japanese women: an anatomical study

International Urogynecology Journal ◽

10.1007/s00192-003-1107-7 ◽

2004 ◽

Vol 15 (2) ◽

pp. 85-94 ◽

Cited By ~ 12

Author(s):

Makoto Kurihara ◽

Gen Murakami ◽

Mitsuru Kajiwara ◽

Keisuke Taguchi ◽

Taiji Tsukamoto ◽

...

Keyword(s):

Smooth Muscle ◽

Anatomical Study ◽

Muscle Layer ◽

Japanese Women ◽

Smooth Muscle Layer ◽

Circular Smooth Muscle ◽

Elderly Japanese Women ◽

Elderly Japanese ◽

Proximal Urethra

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Immunoelectron microscopic localization of fibronectin in the smooth muscle layer of mouse small intestine.

Journal of Histochemistry & Cytochemistry ◽

10.1177/35.4.3546487 ◽

1987 ◽

Vol 35 (4) ◽

pp. 411-417 ◽

Cited By ~ 7

Author(s):

K Kurisu ◽

Y Ohsaki ◽

K Nagata ◽

T Kukita ◽

H Yoshikawa ◽

...

Keyword(s):

Extracellular Matrix ◽

Smooth Muscle ◽

Small Intestine ◽

Smooth Muscle Cells ◽

Basal Lamina ◽

Muscle Cells ◽

Muscle Layer ◽

Secretory Vesicle ◽

Smooth Muscle Layer ◽

Mouse Small Intestine

We studied the ultrastructural distribution of fibronectin in the smooth muscle layer of mouse small intestine with affinity-purified antibodies using the immunogold technique. Fibronectin was present over the pericellular area extending from the cell membrane to the extracellular matrix beyond the basal lamina. Distribution of the glycoprotein over the pericellular area was heterogeneous, i.e., it was localized more abundantly in the narrow space between smooth muscle cells, the gaps having a width of 60-80 nm where the two dense bands in adjacent cells matched each other. Such localization suggests that fibronectin contributes to cell adhesion. Within the basement membrane, gold label was localized both in lamina lucida and lamina densa, more densely in the latter than in the former. Fibronectin was also co-distributed with collagen fibers in the extracellular matrix. Within smooth muscle cells, gold particles were observed on rough endoplasmic reticulum and secretory vesicle-like structures. These results suggest that smooth muscle cells synthesize fibronectin and secrete it as a component of the basal lamina and extracellular matrix.

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Membrane potential gradient is carbon monoxide-dependent in mouse and human small intestine

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00037.2007 ◽

2007 ◽

Vol 293 (2) ◽

pp. G438-G445 ◽

Cited By ~ 25

Author(s):

Lei Sha ◽

Gianrico Farrugia ◽

W. Scott Harmsen ◽

Joseph H. Szurszewski

Keyword(s):

Carbon Monoxide ◽

Smooth Muscle ◽

Small Intestine ◽

Smooth Muscle Cells ◽

Circular Muscle ◽

Muscle Cells ◽

Muscle Layer ◽

Wild Type ◽

Circular Smooth Muscle ◽

Human Small Intestine

The aims of this study were to quantify the change in resting membrane potential (RMP) across the thickness of the circular muscle layer in the mouse and human small intestine and to determine whether the gradient in RMP is dependent on the endogenous production of carbon monoxide (CO). Conventional sharp glass microelectrodes were used to record the RMPs of circular smooth muscle cells at different depths in the human small intestine and in wild-type, HO2-KO, and W/WV mutant mouse small intestine. In the wild-type mouse and human intestine, the RMP of circular smooth muscle cells near the myenteric plexus was −65.3 ± 2 mV and −58.4 ± 2 mV, respectively, and −60.1 ± 2 mV and −49.1 ± 1 mV, respectively, in circular smooth muscle cells at the submucosal border. Oxyhemoglobin (20 μM), a trapping agent for CO, and chromium mesoporphyrin IX, an inhibitor of heme oxygenase, abolished the transwall gradient. The RMP gradients in mouse and human small intestine were not altered by NG-nitro-l-arginine (200 μM). No transwall RMP gradient was found in HO2-KO mice and W/WV mutant mice. TTX (1 μM) and 1H-[1,2,4-]oxadiazolo[4,3-a]quinoxalin-1-one (10 μM) had no effect on the RMP gradient. These data suggest that the gradient in RMP across the thickness of the circular muscle layer of mouse and human small intestine is CO dependent.

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