Journal of Smooth Muscle Research

Intestinal spasms are violent contractions that occur in the intestine, which cause discomfort to people who have them. Medicinal plants are widely used in traditional Moroccan medicine to treat these problems, among these being Artemisia campestris L. This study aims to evaluate the relaxant and antispasmodic effects of an aqueous extract of this plant (ACAE). It was performed in vitro on isolated segments of both isolated rat and rabbit jejunum mounted in an organ bath and tension recordings made via an isotonic transducer...

The characteristic mechanical activities of the smooth muscles found in all organs of the body are highly variable and depend mainly on the spatial arrangement of the muscle cells and the stroma: mass, orientation, relationships, links, constraints, which are deployed in various configurations. These structural features are examined here for their mechanical relevance, in light and electron microscopic views of several muscles of viscera and blood vessels, in a selection of mammalian species. Smooth muscles are incompressible and therefore maintain constant volume...

Pompe disease is a lysosomal storage disease caused by mutations within the GAA gene, which encodes acid α-glucosidase (GAA)-an enzyme necessary for lysosomal glycogen degradation. A lack of GAA results in an accumulation of glycogen in cardiac and skeletal muscle, as well as in motor neurons. The only FDA approved treatment for Pompe disease-an enzyme replacement therapy (ERT)-increases survival of patients, but has unmasked previously unrecognized clinical manifestations of Pompe disease. These clinical signs and symptoms include tracheo-bronchomalacia, vascular aneurysms, and gastro-intestinal discomfort...

This review highlights molecular mechanisms of anti-inflammatory and protective effects of the nuclear transcription factor, peroxisome proliferator-activated receptor γ (PPARγ) in vascular tissue. PPARγ is an ubiquitously expressed nuclear factor, and well-studied in adipose tissue and inflammatory cells. Additionally, beneficial effects of vascular PPARγ's on atherosclerosis and vascular remodeling/dysfunction have been reported although the detailed mechanism remains to be completely elucidated. Clinical and basic studies have shown that the synthetic PPARγ ligands, thiazolidinediones (TZDs), have protective effects against cardiovascular diseases such as atherosclerosis...

Gastric contractions show two specific patterns in many species, migrating motor contractions (MMC) and postprandial contractions (PPCs), that occur in the fasted and fed states, respectively. In this study, we examined the role of somatostatin (SST) in gastric motility both in vivo and in vitro using the Asian house shrew (Suncus murinus). We performed in vivo recordings of gastric motility and in vitro organ bath experiments using S. murinus, which was recently established as a small laboratory animal for use in tests of gastrointestinal motility...

The c-Kit receptor tyrosine kinase regulates the development and differentiation of several progenitor cells. In the gastrointestinal (GI) tract, the c-Kit regulates the development of the interstitial cells of Cajal (ICC) that are responsible for motility regulation of the GI musculature. W-sash (Wsh ) is an inversion mutation upstream of the c-kit promoter region that affects a key regulatory element, resulting in cell-type-specific altered gene expression, leading to a decrease in the number of mast cells, melanocytes, and ICC...

Oropharyngeal dysphagia (OD) is a common symptom in the older people, and may cause fatal complications such as aspiration pneumonia. However, there is no established treatment for OD. The relationship between the transient receptor potential vanilloid 1 (TRPV1) and substance P released by activated TRPV1 was recently demonstrated. Further, there are several reports showing that capsaicin, a specific agonist of TRPV1, can improve OD. Currently, the evaluation of swallowing is mainly performed by videofluoroscopic examination...

Gastric motility is controlled by slow waves. In general, the activation of the ATP-sensitive K+ (KATP ) channels in the smooth muscle opposes the membrane excitability and produces relaxation. Since metabolic inhibition and/or diabetes mellitus are accompanied by dysfunctions of gastric smooth muscle, we examined the possible roles of KATP channels in human gastric motility. We used human gastric corpus and antrum smooth muscle preparations and recorded the mechanical activities with a conventional contractile measuring system...

Blebbistatin, a potent inhibitor of myosin II, is known to suppress smooth muscle contraction without affecting myosin light chain phosphorylation level. In order to clarify the regulatory mechanisms of blebbistatin on phasic and tonic smooth muscles in detail, we examined the effects of blebbistatin on relaxation process by Ca2+ removal after Ca2+ -induced contraction of β-escin skinned (cell membrane permeabilized) trachea and taenia cecum preparations from guinea pigs. Blebbistatin significantly suppressed the force during relaxation both in skinned trachea and taenia cecum...

Spontaneous rhythmic constrictions known as vasomotion are developed in several microvascular beds in vivo. Vasomotion in arterioles is considered to facilitate blood flow, while venular vasomotion would facilitate tissue metabolite drainage. Mechanisms underlying vasomotion periodically generate synchronous Ca2+ transients in vascular smooth muscle cells (VSMCs). In visceral organs, mural cells (pericytes and VSMCs) in arterioles, capillaries and venules exhibit synchronous spontaneous Ca2+ transients. Since sympathetic regulation is rather limited in the intra-organ microvessels, spontaneous activity of mural cells may play an essential role in maintaining tissue perfusion...

In the past few decades, solid evidence has been accumulated for the pivotal significance of immunoinflammatory processes in the initiation, progression, and exacerbation of many diseases and disorders. This groundbreaking view came from original works by Ross who first described that excessive inflammatory-fibroproliferative response to various forms of insult to the endothelium and smooth muscle of the artery wall is essential for the pathogenesis of atherosclerosis (Ross, Nature 1993; 362(6423): 801-9). It is now widely recognized that both innate and adaptive immune reactions are avidly involved in the inflammation-related remodeling of many tissues and organs...

Gastrointestinal smooth muscle research has evolved from studies on muscle strips to spatiotemporal mapping of whole organ motor and electrical activities. Decades of research on single muscle cells and small sections of isolated musculature from animal models has given us the groundwork for interpretation of human in vivo studies. Human gut motility studies have dramatically improved by high-resolution manometry and high-resolution electrophysiology. The details that emerge from spatiotemporal mapping of high-resolution data are now of such quality that hypotheses can be generated as to the physiology (in healthy subjects) and pathophysiology (in patients) of gastrointestinal (dys) motility...

All the cells of rat detrusor muscle fall into one of five ultrastructural types: muscle cells, fibroblasts, axons and glia, and vascular cells (endothelial cells and pericytes). The tissue is ~79% cellular and 21% non-cellular. Muscle cells occupy 72%, nerves ~4% (1/3 axons, 2/3 glia), and fibroblast >3% of space. Muscle cells (up to 6 µm across and ~600 µm long, packed to almost 100,000 per mm2 ) have surface-to-volume ratio of 2.4 µm2 /µm3 ~93% of cell volume is contractile apparatus, 3.1% mitochondria and 2...

Endothelin (ET) receptor antagonists: BQ-123 (ETA ), BQ-788 (ETB ), tezosentan (dual ET receptor antagonist) protect against the development of postoperative ileus (POI) evoked by ischemia-reperfusion (I/R). The current experiments explored whether ET antagonists prevent the occurrence of POI evoked by surgical gut manipulation. Intestinal transit was assessed by measuring the rate of dye migration subsequent to skin incision (SI), laparotomy (L), or laparotomy and surgical gut handling (L+M) in diethyl ether anaesthesized rats (E)...

Rubratoxin A, a potent inhibitor of PP2A, is known to suppress smooth muscle contraction. The inhibitory role of PP2A in smooth muscle contraction is still unclear. In order to clarify the regulatory mechanisms of PP2A on vascular smooth muscle contractility, we examined the effects of rubratoxin A on the Ca2+ -induced contraction of β-escin skinned carotid artery preparations from guinea pigs. Rubratoxin A at 1 µM and 10 µM significantly inhibited skinned carotid artery contraction at any Ca2+ concentration...

Prostaglandin D2 (PGD2 ), one of the key lipid mediators of allergic airway inflammation, is increased in the airways of asthmatics. However, the role of PGD2 in the pathogenesis of asthma is not fully understood. In the present study, effects of PGD2 on smooth muscle contractility of the airways were determined to elucidate its role in the development of airway hyperresponsiveness (AHR). In a murine model of allergic asthma, antigen challenge to the sensitized animals caused a sustained increase in PGD2 levels in bronchoalveolar lavage (BAL) fluids, indicating that smooth muscle cells of the airways are continually exposed to PGD2 after the antigen exposure...

Gastric contractions exhibit characteristic motor patterns in the fasted state, known as migrating motor contractions (MMC). MMC consist of three periodically repeated phases (phase I, II and III) and are known to be regulated by hormones and the autonomic and enteric nervous systems. However, the central regulation of gastric contractions in the fasted state is not completely understood. Here, we have examined the central effects of motilin, ghrelin, γ-aminobutyric acid (GABA) and L-glutamate signaling on gastric MMC by using suncus (Suncus murinus) as an animal model, because of their similar gastric motor patterns to those observed in humans and dogs...

Pompe disease (OMIM 232300) is an autosomal recessive disorder caused by mutations in the gene encoding acid α-glucosidase (GAA) (EC 3.2.1.20), the enzyme responsible for hydrolyzing lysosomal glycogen. The primary cellular pathology is lysosomal glycogen accumulation in cardiac muscle, skeletal muscle, and motor neurons, which ultimately results in cardiorespiratory failure. However, the severity of pathology and its impact on clinical outcomes are poorly described in smooth muscle. The advent of enzyme replacement therapy (ERT) in 2006 has improved clinical outcomes in infantile-onset Pompe disease patients...

Mechanical stress underlies most aspects of cell and organismal biology. Mechanomedicine is a field of biology that seeks to understand molecular, cellular, tissue, organ, and individual responses to mechanical stimuli and aims to apply the gained knowledge to improve health. Combining biology and engineering, we explore research areas including mechanosensitive ion channels, heart failure, and regenerative medicine.This review will describe our findings in mechanobiology, our establishment of a joint venture business as we developed devices responding to medical needs, and our alliance with other companies...

AIM: To investigate the mechanism of nickel augmented phenylephrine (PE)-induced contraction in isolated segments of Wistar rat aorta. MATERIALS AND METHODS: Effect of varying concentrations of nickel on PE-induced contraction were investigated in isolated segments of Wistar rat aorta using an organ bath system. Aortic rings were pre-incubated with verapamil (1 µM and 20 µM), gadolinium, apocynin, indomethacin or N-G-nitro-L-arginine methyl ester (L-NAME) separately before incubation with nickel...