• frog
  • Anatomical distribution of voltage-dependent membrane capacitance in frog skeletal muscle fibers. (rupress.org)
  • Components of nonlinear capacitance, or charge movement, were localized in the membranes of frog skeletal muscle fibers by studying the effect of 'detubulation' resulting from sudden withdrawal of glycerol from a glycerol-hypertonic solution in which the muscles had been immersed. (rupress.org)
  • Under the assumption that the single channel Ca 2+ current of a ryanodine receptor (RYR) is 0.5-2 pA, the results suggest that 1-5 active RYRs generate an average Ca 2+ spark in a frog intact muscle fiber. (rupress.org)
  • A quantitative model of the three-dimensional spread of Ca 2+ within the myoplasm of frog muscle was first developed for Ca 2+ release by an action potential ( Cannell and Allen, 1984 ). (rupress.org)
  • The main goal of this article is to adapt this model for simulations of Ca 2+ sparks in frog fibers and to find out whether the properties of the simulated sparks agree with those of measured sparks. (rupress.org)
  • Intracellular measurements of the resting potential were made in fibers of the frog sartorius muscle in solutions of varying salt composition and concentration to determine the effects of low ionic strength extracellular solutions on the resting potential. (rupress.org)
  • vertebrate
  • Phylogenetic analysis of vertebrate TnI isoforms demonstrated that each of the muscle type-specific isoforms is more conserved across species than the three isoforms in one given species, indicating early diverged functions of the muscle fiber type-specific isoforms as well as the conservation of functions for each muscle fiber type. (wikipedia.org)
  • subunits
  • Our data evidenced an increase in NaV1.5 channels and the involvement of β subunits in the regulation of sodium current and fiber excitability. (deepdyve.com)
  • More recent studies reported that subunits of fast skeletal muscle troponin (fsTnI, fsTnT, fsTnC) were expressed at significant levels in smooth muscle cells of mouse blood vessels, bladder and bronchi. (wikipedia.org)
  • periphery
  • In muscle, plectin binds to the periphery of Z-discs, and along with the intermediate filament protein desmin, may form lateral linkages among neighboring Z-discs. (wikipedia.org)
  • While their cell bodies are found in the central nervous system (CNS), α motor neurons are also considered part of the somatic nervous system-a branch of the peripheral nervous system (PNS)-because their axons extend into the periphery to innervate skeletal muscles. (wikipedia.org)
  • calcium
  • Experiments are designed to test some fundamental assumptions of the cross-bridge model as well as the role of the protein troponin C (TnC) in the regulation of calcium sensitivity in striated muscle. (wikipedia.org)
  • Troponin C has long been associated with the role of an on/off switch which turns a muscle 'on' by binding calcium or 'off' when it releases calcium. (wikipedia.org)
  • Perturbing the calcium binding region of RLC through site-directed mutagenesis (D47A) decreased tension and stiffness in isolated, skinned skeletal muscle fibers, suggesting that the conformational change induced by calcium binding to RLC is functionally important. (wikipedia.org)
  • It is well established that RLC phosphorylation enhances myofilament sensitivity to calcium in isometrically-contracting, skinned cardiac fibers. (wikipedia.org)
  • conformational
  • Based on the crystal structure, a schematic illustration (Fig. 3) was proposed to show the conformational changes in troponin during muscle activation and relaxation. (wikipedia.org)
  • sensitivity
  • We aimed to investigate how the size, number and location of LDs are associated with insulin sensitivity and muscle fiber types, and are regulated by aerobic training and treatment with an erythropoiesis-stimulating agent (ESA) in healthy young untrained males. (physiology.org)
  • Ca(2+) sensitivity of the contractile apparatus was significantly increased by 8 and 16 mM carnosine (increase in pCa(50) of 0.073 ± 0.007 and 0.116 ± 0.006 pCa units, respectively, in six type I fibers, and 0.063 ± 0.018 and 0.103 ± 0.013 pCa units, respectively, in five type II fibers). (biomedsearch.com)
  • Caffeine-induced force responses were potentiated by 8 mM carnosine in both type I and II fibers, with the potentiation in type II fibers being entirely explicable by the increase in Ca(2+) sensitivity of the contractile apparatus caused by carnosine. (biomedsearch.com)
  • However, the potentiation of caffeine-induced responses caused by carnosine in type I fibers was beyond that expected from the associated increase in Ca(2+) sensitivity of the contractile apparatus and suggestive of increased Ca(2+)-induced Ca(2+) release. (biomedsearch.com)
  • Thus increasing muscle carnosine content likely confers benefits to muscle performance in both fiber types by increasing the Ca(2+) sensitivity of the contractile apparatus and possibly also by aiding Ca(2+) release in type I fibers, helping to lessen or slow the decline in muscle performance during fatiguing stimulation. (biomedsearch.com)
  • Additionally, some horses have been shown to have insulin sensitivity, which improves glucose uptake by muscle cells and contributes to excessive glycogen storage that is already elevated secondary to the GSY1 mutation. (wikipedia.org)
  • sodium
  • González, F. 1999-05-15 00:00:00 The role of methionine residues on the fast inactivation of the sodium channel from toad skeletal muscle fibers was studied with the mild oxidant chloramine-T (CT). (deepdyve.com)
  • Metabolism
  • The GSY1 mutation is associated with altered glucose metabolism (but normal glycogen metabolism), as well as accumulation of high levels of glycogen and abnormal polysaccharide in the muscles of the horse. (wikipedia.org)
  • denervation
  • These channels exhibited increased activation time constant (τm) and reduced conductance, similar to what has been observed in denervated muscles in vivo, where the density of NaV1.5 was increasing progressively after denervation. (deepdyve.com)
  • stiffness
  • While episodes of exertional rhabdomyolysis is one of the most frequent signs associated with affected horses (reported in ~37% of affected animals), other common signs include gait abnormalities, shifting lameness, muscle weakness that may result in an inability to rise, colic-like pain, and muscle fasciculation, atrophy, and/or stiffness (most commonly seen in the semimembranosus, semitendinosus, and longissimus muscles). (wikipedia.org)
  • sensory
  • They constitute the muscle spindle and are innervated by two axons, one sensory and one motor. (wikipedia.org)
  • It is by the sensory information from these two intrafusal fiber types that an individual is able to judge the position of their muscle, and the rate at which it is changing. (wikipedia.org)
  • When the muscle generates force, the sensory terminals are compressed. (wikipedia.org)
  • genes
  • Three homologous genes have evolved in vertebrates, encoding three muscle type-specific isoforms of TnI. (wikipedia.org)
  • Sustained MyoD expression is necessary for retaining the expression of muscle-related genes. (wikipedia.org)
  • KAP1 is localized at muscle-related genes in myoblasts along with both MyoD and Mef2 (a myocyte transcription enhancer factor). (wikipedia.org)
  • The consequence of this coactivator/corepressor recruitment is silenced promoting regions on muscle genes. (wikipedia.org)
  • membrane
  • Nonlinear membrane capacitance measured at different voltages was expressed normalized to accessible linear fiber membrane capacitance. (rupress.org)
  • The cell membrane is anchored to the cell's cytoskeleton by anchor fibers that are approximately 10 nm wide. (wikipedia.org)
  • gene
  • The three muscle fiber type-specific TnI-TnT gene pairs were likely originated from a TnI-like ancestor gene that presumably duplicated to form a closely linked fast TnI-like and fast TnT-like gene pair. (wikipedia.org)
  • Myosin regulatory light chain 2, ventricular/cardiac muscle isoform (MLC-2) also known as the regulatory light chain of myosin (RLC) is a protein that in humans is encoded by the MYL2 gene. (wikipedia.org)
  • gastrocnemius
  • In addition, calcineurin and nuclear factor of activated T cell (NFATc1) protein levels were increased in both the gastrocnemius and soleus muscles, suggesting that the calcineurin/NFATc1 pathway was responsible for the type I fiber transition regardless of PGC-1α, which responded minimally to PHD2 deficiency. (sigmaaldrich.com)
  • On the other hand, the gastrocnemius muscle, one of the muscles of the leg, is innervated by α-MNs within segments S1 and S2, which are found caudally in the spinal cord. (wikipedia.org)
  • consistent
  • however, affected horses will show histological changes consistent with muscle damage at one month of age, and may also show elevations in creatine kinase (CK), an enzyme that elevates with muscle damage. (wikipedia.org)
  • segments
  • Fiber segments, obtained from vastus lateralis muscle of human subjects by needle biopsy, were mechanically skinned, and their Ca(2+) release and contractile apparatus properties were characterized. (biomedsearch.com)
  • Isolated segments of fibers were voltage clamped in a triple Vaseline® gap chamber. (deepdyve.com)
  • As in the brainstem, higher segments of the spinal cord contain α-MNs that innervate muscles higher on the body. (wikipedia.org)
  • stimulation
  • most control muscle fibers show phasic AP-induced Ca 2+ transients, while most fibers exposed to elevated D-glucose displayed biphasic Ca 2+ transients upon single field stimulation. (hindawi.com)
  • mice
  • Indeed, we found that tacrolimus (FK-506), a calcineurin inhibitor, successfully suppressed slow fiber-type formation in PHD2-deficient mice. (sigmaaldrich.com)
  • cells
  • Expression of neural agrin in transfected cells followed by its release and deposition on neighboring fibers induced multiple AChR aggregates. (rupress.org)
  • Talin-1 is also found at focal adhesions of smooth muscle cells and non-muscle cells. (wikipedia.org)
  • Expression of vinculin in muscle cells was strikingly down-regulated. (wikipedia.org)
  • Expression of fsTnI was also found in non-muscle cells, such as human corneal epithelial cells and cartilage. (wikipedia.org)
  • The function of fsTnI expressed in smooth muscle and non-muscle cells is unclear. (wikipedia.org)
  • Myocytes are long, tubular cells that develop from myoblasts to form muscles in a process known as myogenesis. (wikipedia.org)
  • There are various specialized forms of myocytes: cardiac, skeletal, and smooth muscle cells, with various properties. (wikipedia.org)
  • The striated cells of cardiac and skeletal muscles are referred to as muscle fibers. (wikipedia.org)
  • Smooth muscle cells control involuntary movements such as the peristalsis contractions in the oesophagus and stomach. (wikipedia.org)
  • The unusual microstructure of muscle cells has led cell biologists to create specialized terminology. (wikipedia.org)
  • However, each term specific to muscle cells has a counterpart that is used in the terminology applied to other types of cells: The sarcoplasm is the cytoplasm of a muscle fiber. (wikipedia.org)
  • verification needed] The myofibrils of smooth muscle cells are not arranged into sarcomeres. (wikipedia.org)
  • Like other regions of the spinal cord, cells in this lamina are somatotopically organized, meaning that the position of neurons within the spinal cord is associated with what muscles they innervate. (wikipedia.org)
  • type
  • Despite 34% (P = 0.004) fewer LDs, the diameter of individual subsarcolemmal LDs was 20% (P = 0.0004) larger in type 2 fibers than in type 1 fibers. (physiology.org)
  • Prolyl hydroxylase domain 2 deficiency promotes skeletal muscle fiber-type transition via a calcineurin/NFATc1-dependent pathway. (sigmaaldrich.com)
  • The downstream pathway of HIF-α leading to fiber-type shift, however, has not been elucidated. (sigmaaldrich.com)
  • The purpose of this study was therefore to examine the effect of HIF-1α stabilization in PHD2 conditional knockout mouse on skeletal muscle fiber-type transition and to elucidate the involvement of calcineurin pathway on muscle fiber-type transition. (sigmaaldrich.com)
  • Taken together, stabilized HIF-1α induced by PHD2 conditional knockout resulted in the transition of muscle fibers toward a slow fiber type via a calcineurin/NFATc1 signaling pathway. (sigmaaldrich.com)
  • Type 2 PSSM is a category for disorders that lead to abnormal deposition of glycogen in the skeletal muscles of the horse that is not due to mutations in GSY1 or GBE1. (wikipedia.org)
  • occurs
  • Signaling between nerve and muscle occurs at neuromuscular junctions (NMJs), which consist of specialized and precisely apposed pre- and postsynaptic structures separated by a synaptic cleft ( Sanes and Lichtman 1999 ). (rupress.org)
  • Fibrillation also occurs with individual skeletal muscle fibers. (wikipedia.org)
  • nuclear
  • In skeletal muscle, the transcription factors Foxo1 and Foxo3A control expression of proteins that mediate muscle atrophy, making the nuclear concentration and nuclear-cytoplasmic movements of Foxo1 and Foxo3A of therapeutic interest in conditions of muscle wasting. (physiology.org)
  • Our approach allows quantitative kinetic characterization of Foxo1 and Foxo3A nuclear-cytoplasmic movements in living muscle fibers under various experimental conditions. (physiology.org)
  • control
  • There are more α-MNs in the spinal cord than in the brainstem, as the number of α-MNs is directly proportional to the amount of fine motor control in that muscle. (wikipedia.org)
  • For example, the muscles of a single finger have more α-MNs per fiber, and more α-MNs in total, than the muscles of the quadriceps, which allows for finer control of the force a finger applies. (wikipedia.org)