Intracellular calcium translocation during contraction in vertebrate and invertebrate smooth muscles as studied by the pyroantimonate method

1982 ◽  
Vol 60 (4) ◽  
pp. 576-587 ◽  
Author(s):  
Haruo Sugi ◽  
Suechika Suzuki ◽  
Tateo Daimon
Keyword(s):  
Smooth Muscle ◽  
Plasma Membrane ◽  
Coronary Artery ◽  
Intracellular Localization ◽  
Muscle Fibers ◽  
Smooth Muscles ◽  
Electron Microscopic Examination ◽  
Mechanical Activity ◽  
Retractor Muscle ◽  
Electron Microscopic

The intracellular localization of activator Ca and its translocation during the mechanical activity were studied on vertebrate and invertebrate smooth muscles by fixing muscle fibers with a 1% OsO4 solution containing 2% potassium pyroantimonate for electron microscopic examination. When guinea-pig tacnia coli, Mytilus anterior byssal retractor muscle, and Dorabella longitudinal body wall muscle were fixed during the relaxed state, electron-opaque pyroantimonate precipitate containing Ca was localized along the inner surface of the plasma membrane and at other membranous structures in close apposition to the plasma membrane, in accordance with physiological evidence that these muscles contain intracellularly stored activator Ca. When they were fixed during the contracted state, the precipitate was distributed diffusely in the myoplasm in the form of small particles, indicating the release of activator Ca from the peripheral structures. The contraction in dog coronary artery smooth muscle appears to be associated with the inward movement of extracellular Ca. In accordance with this, the resting coronary artery muscle fibers exhibited the precipitate in the lumen of the caveolae, i.e., the bottle-shaped plasma membrane invaginations, but not at the peripheral intracellular structures, though the contracted fibers showed the diffuse distribution of the precipitate in the myoplasm. These results indicate that the pyroantimonate method is very effective in studying the translocation of activator Ca in various types of smooth muscle.

Smooth muscles from spastic coronary artery segments show hypercontractility to histamine

1990 ◽  
Vol 259 (1) ◽  
pp. H9-H13 ◽  
Author(s):  
S. Satoh ◽  
H. Tomoike ◽  
W. Mitsuoka ◽  
S. Egashira ◽  
H. Tagawa ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Coronary Artery ◽  
Coronary Arteries ◽  
Muscle Fibers ◽  
Coronary Spasm ◽  
Smooth Muscles ◽  
Bolus Administration ◽  
Luminal Diameter ◽  
Endothelial Denudation ◽  
Significant Difference

An animal model of coronary spasm was produced in Gottingen miniature pigs by a selective endothelial denudation of the coronary artery. Five months after the denudation, intracoronary bolus administration of 10 micrograms/kg histamine reduced the luminal diameter angiographically by 57 +/- 16 and 17 +/- 10% (P less than 0.01) in the previously denuded and contralateral control coronary arteries. Muscle fibers of 0.08–0.1 mm wide were prepared from circumferential bundles of the medial smooth muscle in the spastic and nonspastic coronary arteries. Upward shifts of either dose-tonic contraction relationships in Ca2(+)-containing solution or dose-monophasic contraction relationships in Ca2(+)-free solution were noted in muscle fibers taken from the spastic site compared with those from the nonspastic site with no difference between the mean effective dose values. After skinning the muscle fibers with saponin, there was no significant difference in the Ca2+ concentration-tension relationships between the two fibers. These findings suggest that an increased number of histaminergic receptors and/or augmentation of signal transduction, but not Ca2+ sensitivity of the contractile proteins in the medial smooth muscle cells, cause histamine-induced coronary hypercontraction.

scholarly journals ULTRASTRUCTURAL ORGANIZATION OF OBLIQUELY STRIATED MUSCLE FIBERS IN ASCARIS LUMBRICOIDES

1965 ◽  
Vol 25 (3) ◽  
pp. 495-515 ◽  
Author(s):  
Jack Rosenbluth
Keyword(s):  
Plasma Membrane ◽  
Striated Muscle ◽  
Muscle Fibers ◽  
Electron Microscopic Examination ◽  
Thick Filament ◽  
Ultrastructural Organization ◽  
Striated Muscles ◽  
Three Dimensional Model ◽  
Electron Microscopic ◽  
Thin Filaments

The somatic musculature of the nematode, Ascaris, is currently thought to consist of smooth muscle fibers, which contain intracellular supporting fibrils arranged in a regular pattern. Electron microscopic examination shows that the muscle fibers are, in fact, comparable to the striated muscles of vertebrates in that they contain interdigitating arrays of thick and thin myofilaments which form H, A, and I bands. In the A bands each thick filament is surrounded by about 10 to 12 thin filaments. The earlier confusion about the classification of this muscle probably arose from the fact that in one longitudinal plane the myofilaments are markedly staggered and, as a result, the striations in that plane of section are not transverse but oblique, forming an angle of only about 6° with the filament axis. The apparent direction of the striations changes with the plane of the section and may vary all the way from radial to longitudinal. A three-dimensional model is proposed which accounts for the appearance of this muscle in various planes. Z lines as such are absent but are replaced by smaller, less orderly, counterpart "Z bundles" to which thin filaments attach. These bundles are closely associated with fibrillar dense bodies and with deep infoldings of the plasma membrane. The invaginations of the plasma membrane together with intracellular, flattened, membranous cisternae form dyads and triads. It is suggested that these complexes, which also occur at the cell surface, may constitute strategically located, low-impedance patches through which local currents are channeled selectively.

Physiological and ultrastructural studies on the longitudinal retractor muscle of a sea cucumber Stichopus japonicus. II. Intracellular localization and translocation of activator calcium during mechanical activity

1982 ◽  
Vol 97 (1) ◽  
pp. 113-119
Author(s):  
S. Suzuki ◽  
H. Sugi
Keyword(s):  
Plasma Membrane ◽  
Sea Cucumber ◽  
Mechanical Response ◽  
Intracellular Localization ◽  
Mechanical Activity ◽  
Retractor Muscle ◽  
Stichopus Japonicus ◽  
X Ray ◽  
Ultrastructural Studies ◽  
High K

1. The intracellular localization and translocation of activator Ca in the longitudinal retractor muscle (LRM) of a sea cucumber Stichopus japonicus were studied by fixing the LRM in a 1% OsO4 solution containing 2% K pyroantimonate. 2. In the resting LRM fibres, electron-opaque pyroantimonate precipitate was mostly localized along the inner surface of the plasma membrane and at the subsarcolemmal vesicles in close apposition to the plasma membrane. 3. In the LRM fibres fixed during the mechanical response to ACh and high [K]0, the precipitate was diffusely distributed in the myoplasm in the form of numerous particles with corresponding decrease in the amount of the precipitate at the peripheral structures. 4. Electron probe X-ray microanalysis showed the presence of Ca in the precipitate, indicating that the precipitate provides a valid measure of Ca localization. 5. These results accord with the view that, in the LRM, the contractile mechanism is activated by the release of Ca from the intracellular structures as well as by the inward movement of extracellular Ca.

HISTOMETRIC AND ULTRASTRUCTURAL ORGANIZATION OF THE NERVIMUSCULAR TERMINALS OF SKELETAL MUSCLES AT A HYPOKINESIA

2019 ◽  
pp. 55-63
Author(s):  
Z. M. Yaschyshyn ◽  
S. L. Popel
Keyword(s):  
Skeletal Muscles ◽  
Structural Adjustment ◽  
Muscle Fibers ◽  
Electron Microscopic Examination ◽  
Nerve Fibers ◽  
Ultrastructural Changes ◽  
Ultrastructural Organization ◽  
Electron Microscopic ◽  
Myelinated Nerve ◽  
Male Wistar Rats

The aim: to study the dynamics of histological and ultrastructural changes in muscle fibers and their neuromuscular endings under conditions of prolonged hypokinesia at different stages of ontogenesis. Methods. Studied skeletal muscles and their peripheral nervous apparatus of laboratory male Wistar rats aged 30 to 270 days. The restriction of motor activity was carried out in special canister cells for 30, 60, 90, and 240 days (5 animals for each term). To determine the type of muscle fiber, the Nahlas histochemical method was used, the Kulchitsky method was used to detect myelinated nerve fibers, the Bilshovsky-Gros method and the electron microscopic method to identify neuromuscular endings. Results. The data of histological and electron microscopic examination of skeletal muscle fibers and their neuromuscular endings under conditions of prolonged hypokinesia indicate their regular restructuring during the development of muscles, the formation of their synapses and structures that are associated with them at different stages of ontogenesis. Conclusion. The study provides an in-depth understanding of the relative frequency and nature of the disturbance of the neuromuscular endings during prolonged hypokinesia and its effect on the dynamics of structural adjustment of individual types of muscle fibers in ontogenesis.

HISTOMETRIC AND ULTRASTRUCTURAL ORGANIZATION OF THE NERVIMUSCULAR TERMINALS OF SKELETAL MUSCLES AT A HYPOKINESIA

2019 ◽  
pp. 55-63
Author(s):  
Z. M. Yaschyshyn ◽  
S. L. Popel
Keyword(s):  
Skeletal Muscles ◽  
Structural Adjustment ◽  
Muscle Fibers ◽  
Electron Microscopic Examination ◽  
Nerve Fibers ◽  
Ultrastructural Changes ◽  
Ultrastructural Organization ◽  
Electron Microscopic ◽  
Myelinated Nerve ◽  
Male Wistar Rats

The aim: to study the dynamics of histological and ultrastructural changes in muscle fibers and their neuromuscular endings under conditions of prolonged hypokinesia at different stages of ontogenesis. Methods. Studied skeletal muscles and their peripheral nervous apparatus of laboratory male Wistar rats aged 30 to 270 days. The restriction of motor activity was carried out in special canister cells for 30, 60, 90, and 240 days (5 animals for each term). To determine the type of muscle fiber, the Nahlas histochemical method was used, the Kulchitsky method was used to detect myelinated nerve fibers, the Bilshovsky-Gros method and the electron microscopic method to identify neuromuscular endings. Results. The data of histological and electron microscopic examination of skeletal muscle fibers and their neuromuscular endings under conditions of prolonged hypokinesia indicate their regular restructuring during the development of muscles, the formation of their synapses and structures that are associated with them at different stages of ontogenesis. Conclusion. The study provides an in-depth understanding of the relative frequency and nature of the disturbance of the neuromuscular endings during prolonged hypokinesia and its effect on the dynamics of structural adjustment of individual types of muscle fibers in ontogenesis.

scholarly journals Influence of layer separation on the determination of stomach smooth muscle properties

2021 ◽  
Author(s):  
Mischa Borsdorf ◽  
Markus Böl ◽  
Tobias Siebert
Keyword(s):  
Smooth Muscle ◽  
Muscle Fibers ◽  
Smooth Muscles ◽  
Muscle Layer ◽  
Uniaxial Tensile ◽  
Muscle Properties ◽  
Layer Separation ◽  
Isotonic Contractions ◽  
Longitudinal Layer

AbstractUniaxial tensile experiments are a standard method to determine the contractile properties of smooth muscles. Smooth muscle strips from organs of the urogenital and gastrointestinal tract contain multiple muscle layers with different muscle fiber orientations, which are frequently not separated for the experiments. During strip activation, these muscle fibers contract in deviant orientations from the force-measuring axis, affecting the biomechanical characteristics of the tissue strips. This study aimed to investigate the influence of muscle layer separation on the determination of smooth muscle properties. Smooth muscle strips, consisting of longitudinal and circumferential muscle layers (whole-muscle strips [WMS]), and smooth muscle strips, consisting of only the circumferential muscle layer (separated layer strips [SLS]), have been prepared from the fundus of the porcine stomach. Strips were mounted with muscle fibers of the circumferential layer inline with the force-measuring axis of the uniaxial testing setup. The force–length (FLR) and force–velocity relationships (FVR) were determined through a series of isometric and isotonic contractions, respectively. Muscle layer separation revealed no changes in the FLR. However, the SLS exhibited a higher maximal shortening velocity and a lower curvature factor than WMS. During WMS activation, the transversally oriented muscle fibers of the longitudinal layer shortened, resulting in a narrowing of this layer. Expecting volume constancy of muscle tissue, this narrowing leads to a lengthening of the longitudinal layer, which counteracted the shortening of the circumferential layer during isotonic contractions. Consequently, the shortening velocities of the WMS were decreased significantly. This effect was stronger at high shortening velocities.

scholarly journals Identification of serotonergic (5HT1A-type) receptors in broiler small intestine by application of serotonin and its agonists and antagonists

2011 ◽  
Vol 65 (1-2) ◽  
pp. 51-59 ◽  
Author(s):  
Indira Mujezinovic ◽  
Vitomir Cupic ◽  
Ahmed Smajlovic ◽  
Mehmed Muminovic
Keyword(s):  
Smooth Muscle ◽  
Small Intestine ◽  
Smooth Muscles ◽  
Muscle Layer ◽  
Force Transducer ◽  
Mechanical Activity ◽  
Organ Bath ◽  
Pathological Conditions ◽  
Isolated Organ Bath ◽  
Longitudinal Layer

Serotonin or 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter synthesised from L-tryptophan in serotonergic neurons and enterochromaffin cells of the gastrointestinal tract. This neurotransmitter is widely distributed in the animal and plant kingdom and regulates some central and peripheral functions through several types of specific serotonergic (5-HT) receptors. Since it is known that the effect of serotonin, especially in pathological conditions, is very important, we believe that determining the types of receptors for this substance would make it possible to use their agonist or antagonists, which would undoubtedly enhance the pharmacotherapy of functional disruption of the small intestine in broilers. Investigations were carried out on isolated smooth muscle strips of the circular and longitudinal layer of the broiler small intestine (strip dimension 3-4 mm x 2 cm). The muscle strips were placed in an isolated organ bath. The mechanical activity of the preparations was recorded via an isotonic force transducer coupled to a pen recorder. This was done following the addition of serotonin (nonselective 5-HT agonist), 8-OH-DPAT (selective 5-HT1A agonist) and spiroxatrin (selective 5-HT1A antagonist). The sensitivity of the tissues to acetylcholine was tested before starting the experiments. Using the obtained results, it can be concluded that 5HT1A type receptors are present in smooth muscles of the broiler small intestine, duodenum and ileum, especially in the longitudinal smooth muscle layer which reacted with contractions even to low serotonin concentration (10-6), but not in the jejunum.

A nonisometric kinetic model for smooth muscle

1997 ◽  
Vol 272 (3) ◽  
pp. C1025-C1039 ◽  
Author(s):  
S. N. Yu ◽  
P. E. Crago ◽  
H. J. Chiel
Keyword(s):  
Smooth Muscle ◽  
Length Distribution ◽  
Smooth Muscles ◽  
Retractor Muscle ◽  
Catch Muscle ◽  
Isometric Muscle Contraction ◽  
Anterior Byssus Retractor Muscle ◽  
The Cross ◽  
Cross Bridges ◽  
Bridge Length

We have modeled the nonisometric contractile dynamics of smooth muscle by modifying a four-state model of actin and myosin bonds originally proposed by Hai and Murphy to simulate the isometric contractions of vertebrate smooth muscle. The model includes a latch bridge, which cycles more slowly than regular cross bridges. We generalized this model to represent the calcium-regulated processes of vertebrate and invertebrate smooth muscles. We added length dynamics by assuming length-dependent bonding and unbonding rates for the cross bridges. The calculation of the cross-bridge length distribution was simplified by assuming a Gaussian distribution, as first done by Zahalak for skeletal muscle. To test the performance of this model, we simulated isometric and nonisometric responses of different kinds of smooth muscle, including vascular smooth muscle, airway smooth muscle, molluscan catch muscle (anterior byssus retractor muscle), and Aplysia I(2) muscle. The model captures the economical force maintenance property at the later stages of isometric muscle contraction and responses to imposed lengthening and shortening movements.

Capacity of goat epididymal spermatozoa to undergo the acrosome reaction and subsequent fusion with the egg plasma membrane

1993 ◽  
Vol 5 (3) ◽  
pp. 239 ◽  
Author(s):  
H Harayama ◽  
H Kusunoki ◽  
S Kato
Keyword(s):  
Plasma Membrane ◽  
Acrosome Reaction ◽  
Morphological Changes ◽  
Glass Tube ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Acrosomal Membrane ◽  
Sperm Penetration ◽  
Epididymal Spermatozoa ◽  
Caput Epididymidis

The capacity to undergo the acrosome reaction and subsequent fusion with the egg plasma membrane was examined in goat epididymal spermatozoa. Spermatozoa from the proximal and distal caput and distal cauda were preincubated in a sealed glass tube for induction of the acrosome reaction, and their viability, acrosome morphology and penetrability into zona-free hamster eggs were determined. A simplified triple-stain technique revealed that most of the preincubated live spermatozoa in the samples from the distal caput and distal cauda epididymides underwent morphological changes that indicated the occurrence of the acrosome reaction. Electron microscopic examination revealed that the outer acrosomal membrane of many spermatozoa in these samples showed fusion at multiple sites to the plasma membrane. However, the rates of acrosome-reacted cells in the proximal caput spermatozoa were still lower. The sperm penetration assay demonstrated that the penetration rates of distal caput and distal cauda spermatozoa preincubated for 2 h were 93% and 74% respectively, whereas proximal caput spermatozoa scarcely penetrated into eggs. These results indicate that increasing numbers of goat spermatozoa improve in the functions related to the acrosome reaction and subsequent fusion with the egg plasma membrane during their transit through the caput epididymidis.

scholarly journals The Structure of Mytilus Smooth Muscle and the Electrical Constants of the Resting Muscle

1973 ◽  
Vol 61 (2) ◽  
pp. 207-221 ◽  
Author(s):  
Betty M. Twarog ◽  
Maynard M. Dewey ◽  
Tohoru Hidaka
Keyword(s):  
Connective Tissue ◽  
Muscle Fibers ◽  
Smooth Muscles ◽  
Input Resistance ◽  
Muscle Membrane ◽  
Retractor Muscle ◽  
Current Passing ◽  
Individual Muscle ◽  
The Individual ◽  
Resting Muscle

The individual muscle fibers of the anterior byssus retractor muscle (ABRM) of Mytilus edulis L. are uninucleate, 1.2–1.8 mm in length, 5 µm in diameter, and organized into bundles 100–200 µm in diameter, surrounded by connective tissue. Some bundles run the length of the whole muscle. Adjacent muscle cell membranes are interconnected by nexuses at frequent intervals. Specialized attachments exist between muscle fibers and connective tissue. Electrical constants of the resting muscle membrane were measured with intracellular recording electrodes and both extracellular and intracellular current-passing electrodes. With an intracellular current-passing electrode, the time constant τ, was 4.3 ± 1.5 ms. With current delivered via an extracellular electrode τ was 68.3 ± 15 ms. The space constant, λ, was 1.8 mm ± 0.4. The membrane input resistance, Reff, ranged from 23 to 51 MΩ. The observations that values of τ depend on the method of passing current, and that the value of λ is large relative to fiber length and diameter are considered evidence that the individual muscle fibers are electrically interconnected within bundles in a three-dimensional network. Estimations are made of the membrane resistance, Rm, to compare the values to fast and slow striated muscle fibers and mammalian smooth muscles. The implications of this study in reinterpreting previous mechanical and electrical studies are discussed.

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