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Sarcoplasmic ReticulumCalcium-Transporting ATPasesSarcoplasmic Reticulum Calcium-Transporting ATPasesCalciumEndoplasmic ReticulumRyanodine Receptor Calcium Release ChannelRabbitsCaffeineCalsequestrinRyanodineMusclesMyocardiumCalcium-Binding ProteinsCa(2+) Mg(2+)-ATPaseMyocardial ContractionCalcium SignalingCalcium ChannelsAdenosine TriphosphateRuthenium RedMuscle ProteinsKineticsMyocytes, CardiacMuscle, SkeletalSodium-Calcium ExchangerMagnesiumThapsigarginAdenosine TriphosphatasesExcitation Contraction CouplingEgtazic AcidMuscle ContractionSarcolemmaCalcium Channels, L-TypeMicrosomesTetracaineHeart VentriclesProcaineMuscle Fibers, SkeletalMyofibrilsDantroleneOxalatesBiological Transport, ActiveDogsHeartIntracellular MembranesMalignant HyperthermiaMicroscopy, ElectronMembrane PotentialsEndoplasmic Reticulum StressPhosphorylationVanadiumFluorescent DyesMurexideBiological TransportHydrogen-Ion ConcentrationMuscle Fibers, Fast-TwitchCalcium RadioisotopesXanthenesIndolesBinding SitesEndoplasmic Reticulum, RoughNaphthalenesulfonatesVanadatesMembranesPapillary MusclesLasalocidPotassiumAdenosine DiphosphateFluorescein-5-isothiocyanatePhosphatesAction PotentialsMembrane ProteinsHalothaneTime FactorsIon TransportProtein BindingIsoproterenolSpectrometry, FluorescenceAequorinCytosolRana pipiensAmino Acid SequenceCalcium Channel BlockersVentricular FunctionMolecular Sequence DataStrontiumElectric StimulationProtein ConformationCells, CulturedInositol 1,4,5-Trisphosphate ReceptorsGuinea PigsMicroscopy, ConfocalFreeze FracturingTacrolimus Binding ProteinsLanthanumSaponinsEndoplasmic Reticulum, SmoothCalcium-Calmodulin-Dependent Protein Kinase Type 2TerpenesMuscle CellsLipid BilayersHydrolysisPotassium ChloridePatch-Clamp TechniquesAniline CompoundsCalreticulinGolgi ApparatusCell MembraneModels, BiologicalCalcium Channel AgonistsSodiumCell FractionationRats, WistarFura-2Tacrolimus Binding Protein 1AIon Channel GatingElectric ConductivityCresolsEnzyme InhibitorsOsmolar ConcentrationBuffersRanidaeCardiomegalyCalmodulinAdrenergic beta-AgonistsElectrophysiologyAnuraRats, Sprague-DawleyAdenylyl ImidodiphosphateIon ChannelsMitochondria, MuscleCytoplasmArrhythmias, CardiacHeart FailurePhosphodiesterase InhibitorsCalcium ChlorideTrypsinAlkaloidsProteolipidsHeart AtriaThymolFluorescamineSilver NitrateMuscle, SmoothDetergentsDose-Response Relationship, DrugBufo marinusFerretsThiocyanatesThiazepinesSulfhydryl CompoundsSodium-Potassium-Exchanging ATPaseMetals, Rare EarthMathematicsReceptors, CholinergicMolecular WeightMuscle Fibers, Slow-TwitchTetraphenylborateOrganophosphatesSwineMuscle FatigueDithiothreitolHomeostasisTemperatureModels, CardiovascularCalcimycinOxalic AcidElectrophoresis, Polyacrylamide GelNifedipineChelating AgentsMaleimidesRana temporariaCarrier ProteinsInositol 1,4,5-TrisphosphateMuscle Relaxants, CentralPermeabilityPhospholipidsTrifluoperazineCardiotonic AgentsCell LineSubcellular FractionsMuscle, Smooth, VascularReticulumMitochondria, HeartMutationMagnesium ChlorideCyclic AMP-Dependent Protein KinasesTerbiumCell Membrane PermeabilityBlotting, WesternRana catesbeianaReceptors, Adrenergic, betaPeptide FragmentsProtein TransportBoron CompoundsFluoresceinsIntracellular FluidSarcomeresEthylmaleimideEtiocholanoloneUnfolded Protein ResponseHistological Techniques
Sarcoplasmic Reticulum: A network of tubules and sacs in the cytoplasm of SKELETAL MUSCLE FIBERS that assist with muscle contraction and relaxation by releasing and storing calcium ions.Calcium-Transporting ATPases: Cation-transporting proteins that utilize the energy of ATP hydrolysis for the transport of CALCIUM. They differ from CALCIUM CHANNELS which allow calcium to pass through a membrane without the use of energy.Sarcoplasmic Reticulum Calcium-Transporting ATPases: Calcium-transporting ATPases that catalyze the active transport of CALCIUM into the SARCOPLASMIC RETICULUM vesicles from the CYTOPLASM. They are primarily found in MUSCLE CELLS and play a role in the relaxation of MUSCLES.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Endoplasmic Reticulum: A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)Ryanodine Receptor Calcium Release Channel: A tetrameric calcium release channel in the SARCOPLASMIC RETICULUM membrane of SMOOTH MUSCLE CELLS, acting oppositely to SARCOPLASMIC RETICULUM CALCIUM-TRANSPORTING ATPASES. It is important in skeletal and cardiac excitation-contraction coupling and studied by using RYANODINE. Abnormalities are implicated in CARDIAC ARRHYTHMIAS and MUSCULAR DISEASES.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Caffeine: A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.Calsequestrin: Acidic protein found in SARCOPLASMIC RETICULUM that binds calcium to the extent of 700-900 nmoles/mg. It plays the role of sequestering calcium transported to the interior of the intracellular vesicle.Ryanodine: A methylpyrrole-carboxylate from RYANIA that disrupts the RYANODINE RECEPTOR CALCIUM RELEASE CHANNEL to modify CALCIUM release from SARCOPLASMIC RETICULUM resulting in alteration of MUSCLE CONTRACTION. It was previously used in INSECTICIDES. It is used experimentally in conjunction with THAPSIGARGIN and other inhibitors of CALCIUM ATPASE uptake of calcium into SARCOPLASMIC RETICULUM.Muscles: Contractile tissue that produces movement in animals.Myocardium: The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.Calcium-Binding Proteins: Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.Ca(2+) Mg(2+)-ATPaseMyocardial Contraction: Contractile activity of the MYOCARDIUM.Calcium Signaling: Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.Calcium Channels: Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.Ruthenium Red: An inorganic dye used in microscopy for differential staining and as a diagnostic reagent. In research this compound is used to study changes in cytoplasmic concentrations of calcium. Ruthenium red inhibits calcium transport through membrane channels.Muscle Proteins: The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.Kinetics: The rate dynamics in chemical or physical systems.Myocytes, Cardiac: Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.Sodium-Calcium Exchanger: An electrogenic ion exchange protein that maintains a steady level of calcium by removing an amount of calcium equal to that which enters the cells. It is widely distributed in most excitable membranes, including the brain and heart.Magnesium: A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.Thapsigargin: A sesquiterpene lactone found in roots of THAPSIA. It inhibits CA(2+)-TRANSPORTING ATPASE mediated uptake of CALCIUM into SARCOPLASMIC RETICULUM.Adenosine Triphosphatases: A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.Excitation Contraction Coupling: A process fundamental to muscle physiology whereby an electrical stimulus or action potential triggers a myocyte to depolarize and contract. This mechanical muscle contraction response is regulated by entry of calcium ions into the cell.Egtazic Acid: A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.Muscle Contraction: A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.Sarcolemma: The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Calcium Channels, L-Type: Long-lasting voltage-gated CALCIUM CHANNELS found in both excitable and nonexcitable tissue. They are responsible for normal myocardial and vascular smooth muscle contractility. Five subunits (alpha-1, alpha-2, beta, gamma, and delta) make up the L-type channel. The alpha-1 subunit is the binding site for calcium-based antagonists. Dihydropyridine-based calcium antagonists are used as markers for these binding sites.Microsomes: Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Tetracaine: A potent local anesthetic of the ester type used for surface and spinal anesthesia.Heart Ventricles: The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.Procaine: A local anesthetic of the ester type that has a slow onset and a short duration of action. It is mainly used for infiltration anesthesia, peripheral nerve block, and spinal block. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1016).Muscle Fibers, Skeletal: Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.Myofibrils: The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .Dantrolene: Skeletal muscle relaxant that acts by interfering with excitation-contraction coupling in the muscle fiber. It is used in spasticity and other neuromuscular abnormalities. Although the mechanism of action is probably not central, dantrolene is usually grouped with the central muscle relaxants.Oxalates: Derivatives of OXALIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that are derived from the ethanedioic acid structure.Biological Transport, Active: The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Heart: The hollow, muscular organ that maintains the circulation of the blood.Intracellular Membranes: Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.Malignant Hyperthermia: Rapid and excessive rise of temperature accompanied by muscular rigidity following general anesthesia.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Endoplasmic Reticulum Stress: Various physiological or molecular disturbances that impair ENDOPLASMIC RETICULUM function. It triggers many responses, including UNFOLDED PROTEIN RESPONSE, which may lead to APOPTOSIS; and AUTOPHAGY.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Vanadium: A metallic element with the atomic symbol V, atomic number 23, and atomic weight 50.94. It is used in the manufacture of vanadium steel. Prolonged exposure can lead to chronic intoxication caused by absorption usually via the lungs.Fluorescent Dyes: Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.Murexide: 5,5'-Nitrilodibarbituric acid ammonium derivative. Used as an indicator for complexometric titrations.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Muscle Fibers, Fast-Twitch: Skeletal muscle fibers characterized by their expression of the Type II MYOSIN HEAVY CHAIN isoforms which have high ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment. Several fast types have been identified.Calcium Radioisotopes: Unstable isotopes of calcium that decay or disintegrate emitting radiation. Ca atoms with atomic weights 39, 41, 45, 47, 49, and 50 are radioactive calcium isotopes.Xanthenes: Compounds with three aromatic rings in linear arrangement with an OXYGEN in the center ring.Indoles: Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Endoplasmic Reticulum, Rough: A type of endoplasmic reticulum (ER) where polyribosomes are present on the cytoplasmic surfaces of the ER membranes. This form of ER is prominent in cells specialized for protein secretion and its principal function is to segregate proteins destined for export or intracellular utilization.Naphthalenesulfonates: A class of organic compounds that contains a naphthalene moiety linked to a sulfonic acid salt or ester.Vanadates: Oxyvanadium ions in various states of oxidation. They act primarily as ion transport inhibitors due to their inhibition of Na(+)-, K(+)-, and Ca(+)-ATPase transport systems. They also have insulin-like action, positive inotropic action on cardiac ventricular muscle, and other metabolic effects.Membranes: Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.Papillary Muscles: Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.Lasalocid: Cationic ionophore antibiotic obtained from Streptomyces lasaliensis that, among other effects, dissociates the calcium fluxes in muscle fibers. It is used as a coccidiostat, especially in poultry.Potassium: An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.Adenosine Diphosphate: Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.Fluorescein-5-isothiocyanate: Fluorescent probe capable of being conjugated to tissue and proteins. It is used as a label in fluorescent antibody staining procedures as well as protein- and amino acid-binding techniques.Phosphates: Inorganic salts of phosphoric acid.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Halothane: A nonflammable, halogenated, hydrocarbon anesthetic that provides relatively rapid induction with little or no excitement. Analgesia may not be adequate. NITROUS OXIDE is often given concomitantly. Because halothane may not produce sufficient muscle relaxation, supplemental neuromuscular blocking agents may be required. (From AMA Drug Evaluations Annual, 1994, p178)Time Factors: Elements of limited time intervals, contributing to particular results or situations.Ion Transport: The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Isoproterenol: Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Aequorin: A photoprotein isolated from the bioluminescent jellyfish Aequorea. It emits visible light by an intramolecular reaction when a trace amount of calcium ion is added. The light-emitting moiety in the bioluminescence reaction is believed to be 2-amino-3-benzyl-5-(p-hydroxyphenyl)pyrazine (AF-350).Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.Rana pipiens: A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Calcium Channel Blockers: A class of drugs that act by selective inhibition of calcium influx through cellular membranes.Ventricular Function: The hemodynamic and electrophysiological action of the HEART VENTRICLES.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Strontium: An element of the alkaline earth family of metals. It has the atomic symbol Sr, atomic number 38, and atomic weight 87.62.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Inositol 1,4,5-Trisphosphate Receptors: Intracellular receptors that bind to INOSITOL 1,4,5-TRISPHOSPHATE and play an important role in its intracellular signaling. Inositol 1,4,5-trisphosphate receptors are calcium channels that release CALCIUM in response to increased levels of inositol 1,4,5-trisphosphate in the CYTOPLASM.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Microscopy, Confocal: A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.Freeze Fracturing: Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.Tacrolimus Binding Proteins: A family of immunophilin proteins that bind to the immunosuppressive drugs TACROLIMUS (also known as FK506) and SIROLIMUS. EC 5.2.1.-Lanthanum: Lanthanum. The prototypical element in the rare earth family of metals. It has the atomic symbol La, atomic number 57, and atomic weight 138.91. Lanthanide ion is used in experimental biology as a calcium antagonist; lanthanum oxide improves the optical properties of glass.Saponins: A type of glycoside widely distributed in plants. Each consists of a sapogenin as the aglycone moiety, and a sugar. The sapogenin may be a steroid or a triterpene and the sugar may be glucose, galactose, a pentose, or a methylpentose.Endoplasmic Reticulum, Smooth: A type of endoplasmic reticulum lacking associated ribosomes on the membrane surface. It exhibits a wide range of specialized metabolic functions including supplying enzymes for steroid synthesis, detoxification, and glycogen breakdown. In muscle cells, smooth endoplasmic reticulum is called SARCOPLASMIC RETICULUM.Calcium-Calmodulin-Dependent Protein Kinase Type 2: A multifunctional calcium-calmodulin-dependent protein kinase subtype that occurs as an oligomeric protein comprised of twelve subunits. It differs from other enzyme subtypes in that it lacks a phosphorylatable activation domain that can respond to CALCIUM-CALMODULIN-DEPENDENT PROTEIN KINASE KINASE.Terpenes: A class of compounds composed of repeating 5-carbon units of HEMITERPENES.Muscle Cells: Mature contractile cells, commonly known as myocytes, that form one of three kinds of muscle. The three types of muscle cells are skeletal (MUSCLE FIBERS, SKELETAL), cardiac (MYOCYTES, CARDIAC), and smooth (MYOCYTES, SMOOTH MUSCLE). They are derived from embryonic (precursor) muscle cells called MYOBLASTS.Lipid Bilayers: Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Potassium Chloride: A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.Patch-Clamp Techniques: An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.Aniline CompoundsCalreticulin: A multifunctional protein that is found primarily within membrane-bound organelles. In the ENDOPLASMIC RETICULUM it binds to specific N-linked oligosaccharides found on newly-synthesized proteins and functions as a MOLECULAR CHAPERONE that may play a role in PROTEIN FOLDING or retention and degradation of misfolded proteins. In addition calreticulin is a major storage form for CALCIUM and functions as a calcium-signaling molecule that can regulate intracellular calcium HOMEOSTASIS.Golgi Apparatus: A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Calcium Channel Agonists: Agents that increase calcium influx into calcium channels of excitable tissues. This causes vasoconstriction in VASCULAR SMOOTH MUSCLE and/or CARDIAC MUSCLE cells as well as stimulation of insulin release from pancreatic islets. Therefore, tissue-selective calcium agonists have the potential to combat cardiac failure and endocrinological disorders. They have been used primarily in experimental studies in cell and tissue culture.Sodium: A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.Cell Fractionation: Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Fura-2: A fluorescent calcium chelating agent which is used to study intracellular calcium in tissues.Tacrolimus Binding Protein 1A: A 12-KDa tacrolimus binding protein that is found associated with and may modulate the function of calcium release channels. It is a peptidyl-prolyl cis/trans isomerase which is inhibited by both tacrolimus (commonly called FK506) and SIROLIMUS.Ion Channel Gating: The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.Electric Conductivity: The ability of a substrate to allow the passage of ELECTRONS.CresolsEnzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.Osmolar Concentration: The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.Buffers: A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.Ranidae: The family of true frogs of the order Anura. The family occurs worldwide except in Antarctica.Cardiomegaly: Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.Calmodulin: A heat-stable, low-molecular-weight activator protein found mainly in the brain and heart. The binding of calcium ions to this protein allows this protein to bind to cyclic nucleotide phosphodiesterases and to adenyl cyclase with subsequent activation. Thereby this protein modulates cyclic AMP and cyclic GMP levels.Adrenergic beta-Agonists: Drugs that selectively bind to and activate beta-adrenergic receptors.Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Anura: An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Adenylyl Imidodiphosphate: 5'-Adenylic acid, monoanhydride with imidodiphosphoric acid. An analog of ATP, in which the oxygen atom bridging the beta to the gamma phosphate is replaced by a nitrogen atom. It is a potent competitive inhibitor of soluble and membrane-bound mitochondrial ATPase and also inhibits ATP-dependent reactions of oxidative phosphorylation.Ion Channels: Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.Mitochondria, Muscle: Mitochondria of skeletal and smooth muscle. It does not include myocardial mitochondria for which MITOCHONDRIA, HEART is available.Cytoplasm: The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Arrhythmias, Cardiac: Any disturbances of the normal rhythmic beating of the heart or MYOCARDIAL CONTRACTION. Cardiac arrhythmias can be classified by the abnormalities in HEART RATE, disorders of electrical impulse generation, or impulse conduction.Heart Failure: A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (VENTRICULAR DYSFUNCTION), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as MYOCARDIAL INFARCTION.Phosphodiesterase Inhibitors: Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases.Calcium Chloride: A salt used to replenish calcium levels, as an acid-producing diuretic, and as an antidote for magnesium poisoning.Trypsin: A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.Alkaloids: Organic nitrogenous bases. Many alkaloids of medical importance occur in the animal and vegetable kingdoms, and some have been synthesized. (Grant & Hackh's Chemical Dictionary, 5th ed)Proteolipids: Protein-lipid combinations abundant in brain tissue, but also present in a wide variety of animal and plant tissues. In contrast to lipoproteins, they are insoluble in water, but soluble in a chloroform-methanol mixture. The protein moiety has a high content of hydrophobic amino acids. The associated lipids consist of a mixture of GLYCEROPHOSPHATES; CEREBROSIDES; and SULFOGLYCOSPHINGOLIPIDS; while lipoproteins contain PHOSPHOLIPIDS; CHOLESTEROL; and TRIGLYCERIDES.Heart Atria: The chambers of the heart, to which the BLOOD returns from the circulation.Thymol: A phenol obtained from thyme oil or other volatile oils used as a stabilizer in pharmaceutical preparations, and as an antiseptic (antibacterial or antifungal) agent. It was formerly used as a vermifuge.Fluorescamine: A nonfluorescent reagent for the detection of primary amines, peptides and proteins. The reaction products are highly fluorescent.Silver Nitrate: A silver salt with powerful germicidal activity. It has been used topically to prevent OPHTHALMIA NEONATORUM.Muscle, Smooth: Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)Detergents: Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Bufo marinus: A species of the true toads, Bufonidae, becoming fairly common in the southern United States and almost pantropical. The secretions from the skin glands of this species are very toxic to animals.Ferrets: Semidomesticated variety of European polecat much used for hunting RODENTS and/or RABBITS and as a laboratory animal. It is in the subfamily Mustelinae, family MUSTELIDAE.Thiocyanates: Organic derivatives of thiocyanic acid which contain the general formula R-SCN.ThiazepinesSulfhydryl Compounds: Compounds containing the -SH radical.Sodium-Potassium-Exchanging ATPase: An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.Metals, Rare Earth: A group of elements that include SCANDIUM; YTTRIUM; and the LANTHANOID SERIES ELEMENTS. Historically, the rare earth metals got their name from the fact that they were never found in their pure elemental form, but as an oxide. In addition they were very difficult to purify. They are not truly rare and comprise about 25% of the metals in the earth's crust.Mathematics: The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Receptors, Cholinergic: Cell surface proteins that bind acetylcholine with high affinity and trigger intracellular changes influencing the behavior of cells. Cholinergic receptors are divided into two major classes, muscarinic and nicotinic, based originally on their affinity for nicotine and muscarine. Each group is further subdivided based on pharmacology, location, mode of action, and/or molecular biology.Molecular Weight: The sum of the weight of all the atoms in a molecule.Muscle Fibers, Slow-Twitch: Skeletal muscle fibers characterized by their expression of the Type I MYOSIN HEAVY CHAIN isoforms which have low ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment.Tetraphenylborate: An anionic compound that is used as a reagent for determination of potassium, ammonium, rubidium, and cesium ions. It also uncouples oxidative phosphorylation and forms complexes with biological materials, and is used in biological assays.Organophosphates: Carbon-containing phosphoric acid derivatives. Included under this heading are compounds that have CARBON atoms bound to one or more OXYGEN atoms of the P(=O)(O)3 structure. Note that several specific classes of endogenous phosphorus-containing compounds such as NUCLEOTIDES; PHOSPHOLIPIDS; and PHOSPHOPROTEINS are listed elsewhere.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Muscle Fatigue: A state arrived at through prolonged and strong contraction of a muscle. Studies in athletes during prolonged submaximal exercise have shown that muscle fatigue increases in almost direct proportion to the rate of muscle glycogen depletion. Muscle fatigue in short-term maximal exercise is associated with oxygen lack and an increased level of blood and muscle lactic acid, and an accompanying increase in hydrogen-ion concentration in the exercised muscle.Dithiothreitol: A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.Homeostasis: The processes whereby the internal environment of an organism tends to remain balanced and stable.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Models, Cardiovascular: Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.Calcimycin: An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.Oxalic Acid: A strong dicarboxylic acid occurring in many plants and vegetables. It is produced in the body by metabolism of glyoxylic acid or ascorbic acid. It is not metabolized but excreted in the urine. It is used as an analytical reagent and general reducing agent.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Nifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.Chelating Agents: Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.MaleimidesRana temporaria: A species of the family Ranidae occurring in a wide variety of habitats from within the Arctic Circle to South Africa, Australia, etc.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Inositol 1,4,5-Trisphosphate: Intracellular messenger formed by the action of phospholipase C on phosphatidylinositol 4,5-bisphosphate, which is one of the phospholipids that make up the cell membrane. Inositol 1,4,5-trisphosphate is released into the cytoplasm where it releases calcium ions from internal stores within the cell's endoplasmic reticulum. These calcium ions stimulate the activity of B kinase or calmodulin.Muscle Relaxants, Central: A heterogeneous group of drugs used to produce muscle relaxation, excepting the neuromuscular blocking agents. They have their primary clinical and therapeutic uses in the treatment of muscle spasm and immobility associated with strains, sprains, and injuries of the back and, to a lesser degree, injuries to the neck. They have been used also for the treatment of a variety of clinical conditions that have in common only the presence of skeletal muscle hyperactivity, for example, the muscle spasms that can occur in MULTIPLE SCLEROSIS. (From Smith and Reynard, Textbook of Pharmacology, 1991, p358)Permeability: Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.Phospholipids: Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.Trifluoperazine: A phenothiazine with actions similar to CHLORPROMAZINE. It is used as an antipsychotic and an antiemetic.Cardiotonic Agents: Agents that have a strengthening effect on the heart or that can increase cardiac output. They may be CARDIAC GLYCOSIDES; SYMPATHOMIMETICS; or other drugs. They are used after MYOCARDIAL INFARCT; CARDIAC SURGICAL PROCEDURES; in SHOCK; or in congestive heart failure (HEART FAILURE).Cell Line: Established cell cultures that have the potential to propagate indefinitely.Subcellular Fractions: Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)Muscle, Smooth, Vascular: The nonstriated involuntary muscle tissue of blood vessels.Reticulum: The second stomach of ruminants. It lies almost in the midline in the front of the abdomen, in contact with the liver and diaphragm and communicates freely with the RUMEN via the ruminoreticular orifice. The lining of the reticulum is raised into folds forming a honeycomb pattern over the surface. (From Concise Veterinary Dictionary, 1988)Mitochondria, Heart: The mitochondria of the myocardium.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Magnesium Chloride: Magnesium chloride. An inorganic compound consisting of one magnesium and two chloride ions. The compound is used in medicine as a source of magnesium ions, which are essential for many cellular activities. It has also been used as a cathartic and in alloys.Cyclic AMP-Dependent Protein Kinases: A group of enzymes that are dependent on CYCLIC AMP and catalyze the phosphorylation of SERINE or THREONINE residues on proteins. Included under this category are two cyclic-AMP-dependent protein kinase subtypes, each of which is defined by its subunit composition.Terbium: Terbium. An element of the rare earth family of metals. It has the atomic symbol Tb, atomic number 65, and atomic weight 158.92.Cell Membrane Permeability: A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Rana catesbeiana: A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.Receptors, Adrenergic, beta: One of two major pharmacologically defined classes of adrenergic receptors. The beta adrenergic receptors play an important role in regulating CARDIAC MUSCLE contraction, SMOOTH MUSCLE relaxation, and GLYCOGENOLYSIS.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Protein Transport: The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.Boron Compounds: Inorganic or organic compounds that contain boron as an integral part of the molecule.Fluoresceins: A family of spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one derivatives. These are used as dyes, as indicators for various metals, and as fluorescent labels in immunoassays.Intracellular Fluid: The fluid inside CELLS.Sarcomeres: The repeating contractile units of the MYOFIBRIL, delimited by Z bands along its length.Ethylmaleimide: A sulfhydryl reagent that is widely used in experimental biochemical studies.Etiocholanolone: The 5-beta-reduced isomer of ANDROSTERONE. Etiocholanolone is a major metabolite of TESTOSTERONE and ANDROSTENEDIONE in many mammalian species including humans. It is excreted in the URINE.Unfolded Protein Response: A cellular response to environmental insults that cause disruptions in PROTEIN FOLDING and/or accumulation of defectively folded protein in the ENDOPLASMIC RETICULUM. It consists of a group of regulatory cascades that are triggered as a response to altered levels of calcium and/or the redox state of the endoplasmic reticulum. Persistent activation of the unfolded protein response leads to the induction of APOPTOSIS.Histological Techniques: Methods of preparing tissue for examination and study of the origin, structure, function, or pathology.

A novel interaction mechanism accounting for different acylphosphatase effects on cardiac and fast twitch skeletal muscle sarcoplasmic reticulum calcium pumps. (1/4498)

In cardiac and skeletal muscle Ca2+ translocation from cytoplasm into sarcoplasmic reticulum (SR) is accomplished by different Ca2+-ATPases whose functioning involves the formation and decomposition of an acylphosphorylated phosphoenzyme intermediate (EP). In this study we found that acylphosphatase, an enzyme well represented in muscular tissues and which actively hydrolyzes EP, had different effects on heart (SERCA2a) and fast twitch skeletal muscle SR Ca2+-ATPase (SERCA1). With physiological acylphosphatase concentrations SERCA2a exhibited a parallel increase in the rates of both ATP hydrolysis and Ca2+ transport; in contrast, SERCA1 appeared to be uncoupled since the stimulation of ATP hydrolysis matched an inhibition of Ca2+ pump. These different effects probably depend on phospholamban, which is associated with SERCA2a but not SERCA1. Consistent with this view, the present study suggests that acylphosphatase-induced stimulation of SERCA2a, in addition to an enhanced EP hydrolysis, may be due to a displacement of phospholamban, thus to a removal of its inhibitory effect.  (+info)

Expression of skeletal muscle sarcoplasmic reticulum calcium-ATPase is reduced in rats with postinfarction heart failure. (2/4498)

OBJECTIVE: To determine whether heart failure in rats is associated with altered expression of the skeletal muscle sarcoplasmic reticulum Ca2+-ATPase (SERCA). METHODS: SERCA protein and mRNA were examined in the soleus muscles of eight female rats with heart failure induced by coronary artery ligation, six weeks after the procedure (mean (SEM) left ventricular end diastolic pressure 20.4 (2.2) mm Hg) and in six sham operated controls by western and northern analyses, respectively. RESULTS: SERCA-2a isoform protein was reduced by 16% (112 000 (4000) v 134 000 (2000) arbitrary units, p < 0.001), and SERCA-2a messenger RNA was reduced by 59% (0.24 (0. 06) v 0.58 (0.02) arbitrary units, p < 0.001). Although rats with heart failure had smaller muscles (0.54 mg/g v 0.66 mg/g body weight), no difference in locomotor activity was observed. CONCLUSIONS: These results may explain the previously documented abnormalities in calcium handling in skeletal muscle from animals with the same model of congestive heart failure, and could be responsible for the accelerated muscle fatigue characteristic of patients with heart failure.  (+info)

Ca-releasing action of beta, gamma-methylene adenosine triphosphate on fragmented sarcoplasmic reticulum. (3/4498)

beta,gamma-Methylene adenosine triphosphate (AMPOPCP) has two effects on fragmented sarcoplasmic reticulum (FSR), i.e., inhibition of the rate of Ca uptake and the induction of Ca release from FSR filled with Ca. The Ca release brought about by AMPOPCP has many features in common with the mechanism of Ca-induced Ca release: i) it is inhibited by 10 mM procaine; ii) the amount of Ca release increases with increase in the extent of saturation of FSR with Ca; iii) increase of the Ca concentration in the extent of saturation of FSR with Ca; iii) increase of the Ca concentration in the medium facilitates the release of Ca. However, no facilitation of Ca release upon decrease of Mg concentration in the medium is observable. AMPOPCP and caffeine potentiate each other remarkably in their Ca-releasing action, irrespective of the kind of substrate. From the mode of action of AMPOPCP on the rate of Ca uptake, the amount of phosphorylated intermediate (EP), and the effect on Sr release, it is suggested that the state of the FSR-ATP complex is crucial for Ca-induced Ca release.  (+info)

Mutations of Arg198 in sarcoplasmic reticulum Ca2+-ATPase cause inhibition of hydrolysis of the phosphoenzyme intermediate formed from inorganic phosphate. (4/4498)

Arg198 of sarcoplasmic reticulum Ca2+-ATPase was substituted with lysine, glutamine, glutamic acid, alanine, and isoleucine by site-directed mutagenesis. Kinetic analysis was performed with microsomal membranes isolated from COS-1 cells which were transfected with the mutated cDNAs. The rate of dephosphorylation of the ADP-insensitive phosphoenzyme was determined by first phosphorylating the Ca2+-ATPase with 32Pi and then diluting the sample with non-radioactive Pi. This rate was reduced substantially in the mutant R198Q, more strongly in the mutants R198A and R1981, and most strongly in the mutant R198E, but to a much lesser extent in R198K. The reduction in the rate of dephosphorylation was consistent with the observed decrease in the turnover rate of the Ca2+-ATPase accompanied by the steady-state accumulation of the ADP-insensitive phosphoenzyme formed from ATP. These results indicate that the positive charge and high hydrophilicity of Arg198 are critical for rapid hydrolysis of the ADP-insensitive phosphoenzyme.  (+info)

A repetitive mode of activation of discrete Ca2+ release events (Ca2+ sparks) in frog skeletal muscle fibres. (5/4498)

1. Ca2+ release events (Ca2+ 'sparks'), which are believed to arise from the opening of a sarcoplasmic reticulum (SR) Ca2+ release channel or a small cluster of such channels that act as a release unit, have been measured in single, frog (Rana pipiens) skeletal muscle fibres. 2. Under conditions of extremely low rates of occurrence of Ca2+ sparks we observed, within individual identified triads, repetitive Ca2+ release events which occurred at a frequency more than 100-fold greater than the prevailing average event rate. Repetitive sparks were recorded during voltage-clamp test depolarizations after a brief (0.3-2 s) repriming interval in fibres held at 0 mV and in chronically depolarized, 'notched' fibres. 3. These repetitive events are likely to arise from the re-opening of the same SR Ca2+ release channel or release unit operating in a repetitive gating mode ('rep-mode'), rather than from the random activation of multiple, independent channels or release units within a triad. A train of rep-mode events thus represents a series of Ca2+ sparks arising from a single location within the fibre. Rep-mode events are activated among different triads in a random manner after brief repriming. The frequency of repetitive events among all identified events during voltage-clamp depolarization to 0 mV after brief repriming was 3.9 +/- 1.3 %. The occurrence of repetitive events was not related to exposure of the fibre to laser illumination. 4. The events observed within a rep-mode train exhibited a relatively uniform amplitude. Analysis of intervals between identified events in triads exhibiting rep-mode trains indicated similar variations of fluorescence as in neighbouring, quiescent triads, suggesting there was not a significant number of small, unidentified events at the triads exhibiting rep-mode activity. 5. The distribution of rep-mode interspark intervals exhibited a paucity of events at short intervals, consistent with the need for recovery from inactivation before activation of the next event in a repetitive train. The mean interspark interval of repetitive sparks during voltage-clamp depolarizations was 88 +/- 5 ms, and was independent of membrane potential. 6. The individual Ca2+ sparks within a rep-mode train were similar in average amplitude and spatiotemporal extent to singly occurring sparks, suggesting a common mechanism for termination of the channel opening(s) underlying both types of events. The average properties of the sparks did not vary during a train. The relative amplitude of a spark within a rep-mode was not correlated with its rise time. 7. Repetitive Ca2+ release events represent a mode of gating of SR Ca2+ release channels which may be significant during long depolarizations and which may be influenced by the biochemical state of the SR ryanodine receptor Ca2+ release channels.  (+info)

Local control models of cardiac excitation-contraction coupling. A possible role for allosteric interactions between ryanodine receptors. (6/4498)

In cardiac muscle, release of activator calcium from the sarcoplasmic reticulum occurs by calcium- induced calcium release through ryanodine receptors (RyRs), which are clustered in a dense, regular, two-dimensional lattice array at the diad junction. We simulated numerically the stochastic dynamics of RyRs and L-type sarcolemmal calcium channels interacting via calcium nano-domains in the junctional cleft. Four putative RyR gating schemes based on single-channel measurements in lipid bilayers all failed to give stable excitation-contraction coupling, due either to insufficiently strong inactivation to terminate locally regenerative calcium-induced calcium release or insufficient cooperativity to discriminate against RyR activation by background calcium. If the ryanodine receptor was represented, instead, by a phenomenological four-state gating scheme, with channel opening resulting from simultaneous binding of two Ca2+ ions, and either calcium-dependent or activation-linked inactivation, the simulations gave a good semiquantitative accounting for the macroscopic features of excitation-contraction coupling. It was possible to restore stability to a model based on a bilayer-derived gating scheme, by introducing allosteric interactions between nearest-neighbor RyRs so as to stabilize the inactivated state and produce cooperativity among calcium binding sites on different RyRs. Such allosteric coupling between RyRs may be a function of the foot process and lattice array, explaining their conservation during evolution.  (+info)

Cellular mechanisms of altered contractility in the hypertrophied heart: big hearts, big sparks. (7/4498)

To investigate the cellular mechanisms for altered Ca2+ homeostasis and contractility in cardiac hypertrophy, we measured whole-cell L-type Ca2+ currents (ICa,L), whole-cell Ca2+ transients ([Ca2+]i), and Ca2+ sparks in ventricular cells from 6-month-old spontaneously hypertensive rats (SHRs) and from age- and sex-matched Wistar-Kyoto and Sprague-Dawley control rats. By echocardiography, SHR hearts had cardiac hypertrophy and enhanced contractility (increased fractional shortening) and no signs of heart failure. SHR cells had a voltage-dependent increase in peak [Ca2+]i amplitude (at 0 mV, 1330+/-62 nmol/L [SHRs] versus 836+/-48 nmol/L [controls], P<0.05) that was not associated with changes in ICa,L density or kinetics, resting [Ca2+]i, or Ca2+ content of the sarcoplasmic reticulum (SR). SHR cells had increased time of relaxation. Ca2+ sparks from SHR cells had larger average amplitudes (173+/-192 nmol/L [SHRs] versus 109+/-64 nmol/L [control]; P<0.05), which was due to redistribution of Ca2+ sparks to a larger amplitude population. This change in Ca2+ spark amplitude distribution was not associated with any change in the density of ryanodine receptors, calsequestrin, junctin, triadin 1, Ca2+-ATPase, or phospholamban. Therefore, SHRs with cardiac hypertrophy have increased contractility, [Ca2+]i amplitude, time to relaxation, and average Ca2+ spark amplitude ("big sparks"). Importantly, big sparks occurred without alteration in the trigger for SR Ca2+ release (ICa,L), SR Ca2+ content, or the expression of several SR Ca2+-cycling proteins. Thus, cardiac hypertrophy in SHRs is linked with an alteration in the coupling of Ca2+ entry through L-type Ca2+ channels and the release of Ca2+ from the SR, leading to big sparks and enhanced contractility. Alterations in the microdomain between L-type Ca2+ channels and SR Ca2+ release channels may underlie the changes in Ca2+ homeostasis observed in cardiac hypertrophy. Modulation of SR Ca2+ release may provide a new therapeutic strategy for cardiac hypertrophy and for its progression to heart failure and sudden death.  (+info)

The sarcoplasmic reticulum and the Na+/Ca2+ exchanger both contribute to the Ca2+ transient of failing human ventricular myocytes. (8/4498)

Our objective was to determine the respective roles of the sarcoplasmic reticulum (SR) and the Na+/Ca2+ exchanger in the small, slowly decaying Ca2+ transients of failing human ventricular myocytes. Left ventricular myocytes were isolated from explanted hearts of patients with severe heart failure (n=18). Cytosolic Ca2+, contraction, and action potentials were measured by using indo-1, edge detection, and patch pipettes, respectively. Selective inhibitors of SR Ca2+ transport (thapsigargin) and reverse-mode Na+/Ca2+ exchange activity (No. 7943, Kanebo Ltd) were used to define the respective contribution of these processes to the Ca2+ transient. Ca2+ transients and contractions induced by action potentials (AP transients) at 0.5 Hz exhibited phasic and tonic components. The duration of the tonic component was determined by the action potential duration. Ca2+ transients induced by caffeine (Caf transients) exhibited only a phasic component with a rapid rate of decay that was dependent on extracellular Na+. The SR Ca2+-ATPase inhibitor thapsigargin abolished the phasic component of the AP Ca2+ transient and of the Caf transient but had no significant effect on the tonic component of the AP transient. The Na+/Ca2+ exchange inhibitor No. 7943 eliminated the tonic component of the AP transient and reduced the magnitude of the phasic component. In failing human myocytes, Ca2+ transients and contractions exhibit an SR-related, phasic component and a slow, reverse-mode Na+/Ca2+ exchange-related tonic component. These findings suggest that Ca2+ influx via reverse-mode Na+/Ca2+ exchange during the action potential may contribute to the slow decay of the Ca2+ transient in failing human myocytes.  (+info)

Calcium accumulation by the sarcoplasmic reticulum in two populations of chemically skinned human muscle fibers. Effects of...Calcium accumulation by the sarcoplasmic reticulum in two populations of chemically skinned human muscle fibers. Effects of...
In previous efforts to characterize sarcoplasmic reticulum function in human muscles, it has not been possible to distinguish the relative contributions of fast-twitch and slow-twitch fibers. In this study, we have used light scattering and 45Ca to monitor Ca accumulation by the sarcoplasmic reticulum of isolated, chemically skinned human muscle fibers in the presence and absence of oxalate. Oxalate (5 mM) increased the capacity for Ca accumulation by a factor of 35 and made it possible to assess both rate of Ca uptake and relative sarcoplasmic reticulum volume in individual fibers. At a fixed ionized Ca concentration, the rate and maximal capacity (an index of sarcoplasmic reticulum volume) both varied over a wide range, but fibers fell into two distinct groups (fast and slow). Between the two groups, there was a 2- to 2.5-fold difference in oxalate-supported Ca uptake rates, but no difference in average sarcoplasmic reticulum volumes. Intrinsic differences in sarcoplasmic reticulum function ...
The role of ganglioside GM<sub>3</sub> in the modulation of conformation and activity of sarcoplasmic reticulum CA<sup>2+...The role of ganglioside GM<sub>3</sub> in the modulation of conformation and activity of sarcoplasmic reticulum CA<sup>2+...
TY - JOUR. T1 - The role of ganglioside GM3 in the modulation of conformation and activity of sarcoplasmic reticulum CA2+-ATPase. AU - Yang, F. Y.. AU - Wang, L. H.. AU - Yang, X. Y.. AU - Tsui, Z. C.. AU - Tu, Yaping. PY - 1997/10. Y1 - 1997/10. N2 - Rabbit sarcoplasmic reticulum does contain trace amounts of gangliosides, and the main species is GM3. Incorporation of GM3 into the SR vesicles or addition of it to the soybean phospholipid used for reconstitution of proteoliposomes obviously increased ATP hydrolysis, as well as, Ca2+ uptake activity of sarcoplasmic reticulum Ca2+-ATPase. Conformation changes of Ca2+-ATPase induced by GM3 were also observed by circular dichroism, intrinsic fluorescence and fluorescence quenching measurements.. AB - Rabbit sarcoplasmic reticulum does contain trace amounts of gangliosides, and the main species is GM3. Incorporation of GM3 into the SR vesicles or addition of it to the soybean phospholipid used for reconstitution of proteoliposomes obviously increased ...
Effects of sarcoplasmic reticulum calcium pump inhibitors on vascular smooth muscle. | HypertensionEffects of sarcoplasmic reticulum calcium pump inhibitors on vascular smooth muscle. | Hypertension
A dysfunctioning of Ca2+ pump ATPase in the sarcoplasmic reticulum in vascular smooth muscle has been proposed as a contributing factor for the development of genetic hypertension. In this study, we determined whether in vitro inhibition of the sarcoplasmic reticulum Ca2+ pump in vascular smooth muscle tissues and cultured cells isolated from aortas of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats would elicit the known alterations of contractile function and cell growth. We found the following common vascular effects of thapsigargin and cyclopiazonic acid, which are known to be selective inhibitors of sarcoplasmic reticulum Ca(2+)-ATPase in a number of tissues including smooth muscle: (1) Both sarcoplasmic reticulum Ca2+ pump inhibitors diminished agonist-induced transient contraction in Ca(2+)-free medium (ie, contraction due to intracellular release of Ca2+) and enhanced nifedipine-sensitive contraction on readmission of Ca2+ (ie, Ca2+ influx via L-type channels); and (2) ...
Nitric oxide-dependent activation of CaMKII increases diastolic sarcoplasmic reticulum calcium release in cardiac myocytes in...Nitric oxide-dependent activation of CaMKII increases diastolic sarcoplasmic reticulum calcium release in cardiac myocytes in...
TY - JOUR. T1 - Nitric oxide-dependent activation of CaMKII increases diastolic sarcoplasmic reticulum calcium release in cardiac myocytes in response to adrenergic stimulation. AU - Curran, Jerry. AU - Tang, Lifei. AU - Roof, Steve R.. AU - Velmurugan, Sathya. AU - Millard, Ashley. AU - Shonts, Stephen. AU - Wang, Honglan. AU - Santiago, Demetrio. AU - Ahmad, Usama. AU - Perryman, Matthew. AU - Bers, Donald M. AU - Mohler, Peter J.. AU - Ziolo, Mark T.. AU - Shannon, Thomas R.. PY - 2014/2/3. Y1 - 2014/2/3. N2 - Spontaneous calcium waves in cardiac myocytes are caused by diastolic sarcoplasmic reticulum release (SR Ca2+ leak) through ryanodine receptors. Beta-adrenergic (β-AR) tone is known to increase this leak through the activation of Ca-calmodulin-dependent protein kinase (CaMKII) and the subsequent phosphorylation of the ryanodine receptor. When b-AR drive is chronic, as observed in heart failure, this CaMKII-dependent effect is exaggerated and becomes potentially arrhythmogenic. Recent ...
Junctional sarcoplasmic reticulum protein elisa and antibodyJunctional sarcoplasmic reticulum protein elisa and antibody
Shop Junctional sarcoplasmic reticulum protein ELISA Kit, Recombinant Protein and Junctional sarcoplasmic reticulum protein Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
Characterization of cardiac sarcoplasmic reticulum dysfunction during short-term, normothermic, global ischemia. | Circulation...Characterization of cardiac sarcoplasmic reticulum dysfunction during short-term, normothermic, global ischemia. | Circulation...
It has been proposed that breakdown of the excitation-contraction coupling system plays a pivotal role in myocardial dysfunction during the course of acute ischemia. We tested this hypothesis by characterizing the function of the sarcoplasmic reticulum at pH 7.1 and 6.4 after 7.5, 15, and 30 minutes of canine normothermic global ischemia. At pH 7.1, whole heart homogenate sarcoplasmic reticulum demonstrated a 49% depression of oxalate-supported calcium uptake at 7.5 minutes of ischemia, which progressed to 85% at 30 minutes of ischemia. At pH 6.4, control homogenate calcium uptake rates were significantly depressed, accompanied by a further depression in the ischemic groups. Isolated sarcoplasmic reticulum calcium uptake mirrored the effects of the whole heart homogenate. Calcium-stimulated magnesium-dependent ATPase (calcium-ATPase) activity was significantly depressed by both ischemia and acidosis, with a decrease in the coupling ratio (mumol calcium/mumol ATP) at 15 and 30 minutes of ...
Calcium transport properties of cardiac sarcoplasmic reticulum from cardiomyopathic Syrian hamsters (BIO 53.58 and 14.6):...Calcium transport properties of cardiac sarcoplasmic reticulum from cardiomyopathic Syrian hamsters (BIO 53.58 and 14.6):...
Calcium uptake was measured in homogenates and microsomal preparations enriched in sarcoplasmic reticulum vesicles isolated from hearts of hypertrophic (BIO 14.6) and dilated (BIO 53.58) cardiomyopathic as well as control (F1B) Syrian hamsters at 3, 7, 9, and 11 months of age. Calcium uptake studies were done using the Millipore filtration technique under conditions known to restrict transport to the sarcoplasmic reticulum. Steady-state calcium uptake capacity was used as a measure of the relative amounts of sarcoplasmic reticulum in homogenates prepared from individual hearts. At 3 months of age, there were no differences in calcium uptake in homogenates from control or myopathic hearts. However, by 9 months, although calcium uptake of homogenates from control and hypertrophic hearts was the same, calcium uptake by homogenates from dilated hearts was significantly depressed both in initial rate and capacity. Similar trends were seen in the microsomal vesicle preparations, but the decrease in ...
The regulation of ATPase-ATPase interactions in sarcoplasmic reticulum membrane. I. The effects of Ca2+, ATP, and inorganic...The regulation of ATPase-ATPase interactions in sarcoplasmic reticulum membrane. I. The effects of Ca2+, ATP, and inorganic...
TY - JOUR. T1 - The regulation of ATPase-ATPase interactions in sarcoplasmic reticulum membrane. I. The effects of Ca2+, ATP, and inorganic phosphate.. AU - Dux, L.. AU - Martonosi, A.. PY - 1983/10/10. Y1 - 1983/10/10. N2 - Two-dimensional crystalline arrays of Ca2+-ATPase molecules develop after treatment of sarcoplasmic reticulum vesicles with Na3VO4 in calcium-free medium (Dux, L., and Martonosi, A. (1983) J. Biol. Chem. 258, 2599-2603). The formation of Ca2+-ATPase crystals is inhibited by Ca2+ (2 microM), or ATP (5 mM), but not by ADP, 5-adenylylimidodiphosphate, or adenylylmethylenediphosphonate. ATPase crystals did not form at 37 degrees C and exposure of preformed crystals to 37 degrees C for 1 h caused the disappearance of crystal lattice. Inorganic orthophosphate (1 mM at pH 6.0) promoted the formation of a distinct crystal form of Ca2+-ATPase, which was different from that produced by Na3VO4. These observations indicate that Ca2+, ATP, inorganic phosphate, pH, and temperature ...
Sarcoplasmic Reticulum | Technology TrendsSarcoplasmic Reticulum | Technology Trends
is a human gene associated with the release of Calcium ions from the sarcoplasmic reticulum triggering muscular contraction through calcium-induced calcium release ... It is a transmembrane protein on the sarcoplasmic reticulum due to a well defined hydrophobic section, and it forms a quaternary complex with Ryanodine receptors (RyR ... The luminal (inner compartment of the sarcoplasmic reticulum) section of Triadin has areas of highly charged amino acid residues that act as luminal Ca2+ receptors ...
Sarcoplasmic reticulum Ca<sup>2+</sup> regulatory protein gene expression in human right atrium under hemodynamic...Sarcoplasmic reticulum Ca<sup>2+</sup> regulatory protein gene expression in human right atrium under hemodynamic...
TY - JOUR. T1 - Sarcoplasmic reticulum Ca2+ regulatory protein gene expression in human right atrium under hemodynamic overload. AU - Sadamatsu, Kenji. AU - Urabe, Yoshitoshi. AU - Tsutsui, Hiroyuki. AU - Tagawa, Hirofumi. AU - Maruoka, Fumio. AU - Igarashi-Saito, Keiko. AU - Takeda, Kotaro. AU - Kawachi, Yoshito. AU - Yasui, Hisataka. AU - Takeshita, Akira. PY - 1999/1/1. Y1 - 1999/1/1. N2 - Sarcoplasmic reticulum (SR) Ca2+-adenosine triphosphatase (ATPase) mRNA expression is reduced in the failing human myocardium. However, it is not known whether SR Ca2+-regulatory protein gene expression is altered in human myocardial tissue subjected to pressure overload or volume overload. We sought to determine whether SR Ca2+-regulatory protein gene expression is altered in human atrial tissue subjected to mechanical overload. We obtained right atrial myocardial tissue (about 250 mg) at open-heart surgery from three groups of patients: no hemodynamic overload to the right atrium (control group; 12 ...
Localization of E1-E2 conformational transitions of sarcoplasmic reticulum Ca-ATPase by tryptic cleavage and hydrophobic...Localization of E1-E2 conformational transitions of sarcoplasmic reticulum Ca-ATPase by tryptic cleavage and hydrophobic...
Tryptic peptides of Ca-ATPase in Et and E2 conformational states (Andersen, J. P., Jørgensen, P. L.,J. Membrane Biol. 88:187-198 (1985)) have been isolated by size exclusion high performance liquid chromatography in sodium dodecyl sulfate. This permitted unambiguous localization of a conformational sensitive tryptic split at Arg 198 by N-terminal amino acid sequence analysis. Other splits at Arg 505 and at Arg 819-Lys 825 were insensitive to E1-E2 transitions. Tryptic cleavage of Ca-ATPase after phosphorylation by inorganic phosphate showed that this enzyme form has a conformation similar to that of the vanadate-bound E2 state, both in membranous and in soluble monomeric Ca-ATPase. Hydrophobic labeling of Ca-ATPase in sarcoplasmic reticulum vesicles with the photoactivable reagent trifluoromethyl-[125I]iodophenyl-diazirine indicated that E2 and E2V states are more exposed to the membrane phase than E1 and E1P (Ca2+-occluded) states. The preferetial hydrophobic labeling in E2 forms was found to be
Reactive disulfides trigger Ca<sup>2+</sup> release from sarcoplasmic reticulum via an oxidation...Reactive disulfides trigger Ca<sup>2+</sup> release from sarcoplasmic reticulum via an oxidation...
TY - JOUR. T1 - Reactive disulfides trigger Ca2+ release from sarcoplasmic reticulum via an oxidation reaction. AU - Zaidi, N. F.. AU - Lagenaur, C. F.. AU - Abramson, J. J.. AU - Pessah, Isaac N. AU - Salama, G.. PY - 1989. Y1 - 1989. N2 - Reactive disulfide compounds (RDSs) with a pyridyl ring adjacent to the S-S bond such as 2,2-dithiodipyridine (2,2-DTDP), 4,4-dithiodipyridine, and N-succinimidyl 3(2-pyridyldithio)propionate (SPDP) trigger Ca2+ release from sarcoplasmic reticulum (SR) vesicles. They are known to specifically oxidize free SH sites via a thiol-disulfide exchange reaction with the stoichiometric production of thiopyridone. Thus, the formation of a mixed S-S bond between an accessible SH site on an SR protein and a RDS causes large increases in SR Ca2+ permeability. Reducing agents, glutathione (GSH) of dithiothreitol reverse the effect of RDSs and permit rapid re-uptake of Ca2+ by the Ca2+, Mg2+-ATPase. The RDSs, 2,2-DTDP, 4,4-dithiodipyridine and SPDP displaced ...
Abstract 16909: Sarcoplasmic Reticulum Calcium Leak and Enhanced NCX Increase Occurrence of Delayed Afterdepolarisations in...Abstract 16909: Sarcoplasmic Reticulum Calcium Leak and Enhanced NCX Increase Occurrence of Delayed Afterdepolarisations in...
Introduction: Sarcoplasmic reticulum (SR) Ca2+ leak activates the inward Na+-Ca2+ exchange current (INCX) causing delayed afterdepolarsations (DADs) that promote arrhythmias. Whether this mechanism contributes to promotion of atrial fibrillation (AF) is unknown and was the object of this study.. Methods: Membrane currents and potentials (patch clamp) and [Ca2+]i (Fluo-3) were measured in right-atrial myocytes from sinus rhythm (Ctl) or chronic AF (cAF) patients. Tetracaine (1 mM) or single-channel recordings were used to quantify SR Ca2+ leak through ryanodine-receptor channels (RyR2). Proteins were measured by immunoblotting.. Results: Diastolic [Ca2+]i and SR Ca2+ content (integrated INCX during caffeine-induced [Ca2+]i transient [cCaT]) were unchanged, whereas diastolic SR Ca2+ leak was ∼50% higher in cAF than in Ctl (Figure). Calmodulin expression (+60%), CaMKII autophosphorylation (activation) at Thr287 (+40%) and Ser2808-phosphorylation (PKA/CaMKII-site) of RyR2 (+250%) were higher in ...
The Development of the Sarcoplasmic Reticulum (ebook) by Anthony Martonosi | 9781482283624The Development of the Sarcoplasmic Reticulum (ebook) by Anthony Martonosi | 9781482283624
Buy, download and read The Development of the Sarcoplasmic Reticulum ebook online in PDF format for iPhone, iPad, Android, Computer and Mobile readers. Author: Anthony Martonosi. ISBN: 9781482283624. Publisher: CRC Press. Sarcoplasmic reticulum is a form of endoplasmic reticulum found in large quantities in mature muscle cells. Anthony Martonosi presents general information about the development and function of the sar
Get PDF - The sarcoplasmic reticulum Ca(2+)-ATPase is depressed in stunned myocardium after ischemia-reperfusion, but remains...Get PDF - The sarcoplasmic reticulum Ca(2+)-ATPase is depressed in stunned myocardium after ischemia-reperfusion, but remains...
Xu, K.Y.; Vandegaer, K.; Becker, L.C., 1999: The sarcoplasmic reticulum Ca(2+)-ATPase is depressed in stunned myocardium after ischemia-reperfusion, but remains functionally coupled to sarcoplasmic reticulum-bound glycolytic enzymes
Direct measurement of Ca2+ uptake and release by the sarcoplasmic reticulum of saponin permeabilized isolated smooth muscle...Direct measurement of Ca2+ uptake and release by the sarcoplasmic reticulum of saponin permeabilized isolated smooth muscle...
To make direct measurements of Ca2+ uptake and release by the sarcoplasmic reticulum (SR) of isolated smooth muscle cells, a fluorometric method for monitoring Ca2+ uptake by striated muscle SR vesicles (Kargacin, M.E., C.R. Scheid, and T.W. Honeyman. 1988. American Journal of Physiology. 245:C694-C698) was modified. With the method, it was possible to make continuous measurements of SR function in saponin-skinned smooth muscle cells in suspension. Calcium uptake by the SR was inhibited by thapsigargin and sequestered Ca2+ could be released by Br-A23187 and thapsigargin. From the rate of Ca2+ uptake by the skinned cells and the density of cells in suspension, it was possible to calculate the Ca2+ uptake rate for the SR of a single cell. Our results indicate that the SR Ca2+ pump in smooth muscle cells can remove Ca2+ at a rate that is 45-75% of the rate at which Ca2+ is removed from the cytoplasm of intact cells during transient Ca2+ signals. From estimates of SR volume reported by others and ...
Professor Michael McKenna | Victoria University | Melbourne AustraliaProfessor Michael McKenna | Victoria University | Melbourne Australia
Wyckelsma VL, MJ McKenna, FR Serpiello, CR Lamboley, RJ Aughey, NK Stepto, DJ Bishop and RM Murphy. Single fiber expression and fiber-specific adaptability to short-term intense exercise training of Na+,K+-ATPase α and β isoforms in human skeletal muscle. Journal of Applied Physiology 118(6):699-706, 2015.. Perry BD, Levinger P, Morris HG, Petersen AC, Garnham AP, Levinger I and MJ McKenna. The effects of knee injury on skeletal muscle function, Na+,K+-ATPase content and isoform abundance. Physiological Reports 12;3(2). pii: e12294, 2015.. Lamboley CR, VL Wyckelsma, TL Dutka, MJ McKenna, RM Murphy and GD Lamb. Contractile properties and sarcoplasmic reticulum calcium content in type I and type II skeletal muscle fibres in active aged humans. Journal of Physiology. 593(1):2499-514, 2015.. Lamboley CR, RM Murphy, MJ McKenna and GD Lamb Sarcoplasmic reticulum Ca2+ uptake and leak properties and SERCA protein expression in type I and type II fibres of human skeletal muscle. Journal of Physiology ...
NNIW75 - Nutritional Coaching Strategy to Modulate Training EfficiencyNNIW75 - Nutritional Coaching Strategy to Modulate Training Efficiency
Several recent studies indicate that supplementation of the diet with inorganic nitrate results in a significant reduction in pulmonary O 2 uptake during sub-maximal exercise, an effect that appears to be related to enhanced skeletal muscle efficiency. The physiological mechanisms responsible for this effect are not completely understood but are presumably linked to the bioconversion of ingested nitrate into nitrite and thence to nitric oxide. Nitrite and/or nitric oxide may influence muscle contractile efficiency perhaps via effects on sarcoplasmic reticulum calcium handling or actin-myosin interaction, and may also improve the efficiency of mitochondrial oxidative phosphorylation. A reduced O 2 cost of exercise can be observed within 3 h of the consumption of 5-6 mmol of nitrate, and this effect can be preserved for at least 15 days provided that the same dose of nitrate is consumed daily. A reduced O 2 cost of exercise following nitrate supplementation has now been reported for several ...
Quantitative determination of Ca2+-dependent Mg2+-ATPase from sarcoplasmic reticulum in muscle biopsies | Biochemical JournalQuantitative determination of Ca2+-dependent Mg2+-ATPase from sarcoplasmic reticulum in muscle biopsies | Biochemical Journal
The possibility of quantifying the total concentration of Ca2+-dependent Mg2+-ATPase of sarcoplasmic reticulum was investigated by measurement of the Ca2+-dependent steady-state phosphorylation from [gamma-32P]ATP and the Ca2+-dependent 3-O-methylfluorescein phosphatase (3-O-MFPase) activity in crude muscle homogenates. The Ca2+-dependent phosphorylation at 0 degree C (mean +/- S.E.) was 40.0 +/- 2.5 (n = 6) and 6.2 +/- 0.7 (n = 4) nmol/g wet wt. in rat extensor digitorum longus (EDL) and soleus muscle, respectively (P less than 0.001). The Ca2+-dependent 3-O-MFPase activity at 37 degrees C was 1424 +/- 238 (n = 6) and 335 +/- 56 (n = 4) nmol/min per g wet wt. in rat EDL and soleus muscle, respectively (P less than 0.01). The molecular activity calculated from these measurements amounted to 35 +/- 5 min-1 (n = 6) and 55 +/- 10 min-1 (n = 4) for EDL and soleus muscle respectively. These values were not different from the molecular activity calculated for purified Ca2+-ATPase (36 min-1). The ...
Abstract 414: Translocation of Protein Phosphatase 1 with Inhibitor-2 from Sarcoplasmic Reticulum to Cytosol Augments Ca2+...Abstract 414: Translocation of Protein Phosphatase 1 with Inhibitor-2 from Sarcoplasmic Reticulum to Cytosol Augments Ca2+...
Background: We and others have reported that myocardial protein phosphatase 1(PP1) activity in the end-stage heart failure (HF) is abnormally increased and contributes to the depressed cardiac function. In this regard, in vivo myocardial PP1 inhibition via endogenous cytosolic inhibitors such as inhibitor-2 (INH-2) has prevented HF progression by augmenting phospholamban (PLN) phosphorylation and thereby increasing cardiac function in the genetic cardiomyopathy model. However, it remained uncertain how INH-2, a cytosolic protein, exerts PP1 inhibition in the sarcoplasmic reticulum (SR). To this end, we investigated the molecular mechanism by which INH-2 inhibits PP1 and regulates contractility in cardiomyocytes.. Methods and Results: Cardiomyocytes were enzymatically isolated from six week-old male Wistar rats (n=10) and subjected to either adenoviral INH-2 infection or chemical PP1 inhibition by an application of 0.01-1microM of tautomycin (TM) and tautomycetin (TMC), followed by assessment of ...
Abdominal Pain & Enlarged Vesicles of Sarcoplasmic Reticulum Origin & Pregnancy<...Abdominal Pain & Enlarged Vesicles of Sarcoplasmic Reticulum Origin & Pregnancy<...
Abdominal Pain, Enlarged Vesicles of Sarcoplasmic Reticulum Origin, Pregnancy Symptom Checker: Possible causes include Ovarian Cyst, Constipation, Iron Deficiency. Check the full list of possible causes and conditions now! Talk to our Chatbot to narrow down your search.
Assembly and dynamics of proteins of the longitudinal and junctional sarcoplasmic reticulum in skeletal muscle cells | PNASAssembly and dynamics of proteins of the longitudinal and junctional sarcoplasmic reticulum in skeletal muscle cells | PNAS
FRAP experiments revealed that the dynamics of GFP-SERCA2a, either when diffused throughout the SR or when localized near the Z disk, did not show any difference in the mobile fraction and the diffusion constant (Mf of 88.8% ± 9.1%, n = 16, and 93.2% ± 4.0%, n = 23; D of 0.22 ± 0.1 μm2/s and 0.20 ± 0.1 μm2/s, respectively), as shown in Fig. 2C. The diffusion constant of GFP-InsP3R1 was similar in undifferentiated and differentiated myotubes (D of 0.13 ± 0.07 μm2/s and 0.07 ± 0.05 μm2/s, respectively). However, the Mf of GFP-InsP3R1 was reduced from 79.1% ± 11.2% (n = 20) to 62.8% ± 11.3% (P ≤ 0.01, n = 14) when the protein was organized at the Z disk level (Fig. 2F). InsP3R1 has been described to associate with the actin cytoskeleton through its interaction with protein 4.1N (26, 27). Accordingly, a GFP-InsP3R1 construct missing the C-terminal 14 aa that are responsible for binding to protein 4.1N (28) was prepared (GFP-InsP3R1Δ14). In differentiated myotubes, the GFP-InsP3R1Δ14 ...
Sarcoplasmic reticulum calcium leak and calcium instability in cardiac myocytes - Eric SobieSarcoplasmic reticulum calcium leak and calcium instability in cardiac myocytes - Eric Sobie
With each heartbeat, a small amount of calcium entering the cell through membrane channels triggers the release of a larger amount of calcium from intracellular...
Comparison of the effects of the membraneassociated Ca 2+ /calmodulin-dependent protein kinase on Ca 2+ -ATPase function in...Comparison of the effects of the membraneassociated Ca 2+ /calmodulin-dependent protein kinase on Ca 2+ -ATPase function in...
In both cardiac and slow-twitch skeletal muscle sarcoplasmic reticulum (SR) there are several systems involved in the regulation of Ca2+-ATPase function. T
Direct in vivo monitoring of sarcoplasmic reticulum Ca2+ and cytosolic cAMP dynamics in mouse skeletal muscle | JCBDirect in vivo monitoring of sarcoplasmic reticulum Ca2+ and cytosolic cAMP dynamics in mouse skeletal muscle | JCB
As shown in Fig. 4 C (bottom), the application of isoproterenol also led to a larger fiber deflection, which is indicative of the expected force potentiation. This increase in single-twitch amplitude was paralleled by four interesting phenomena. First, the basal-normalized YFP/CFP ratio increased from 1.00 ± 0.02% to 1.06 ± 0.01% (mean ± SEM; n = 3 fibers) after injection of isoproterenol (Fig. 4 C, top). According to the calibration procedure described in the supplemental material, this would account for a rise in [Ca2+]SR from ∼278 to ∼311 μM. Second, the decrease of YFP/CFP ratio during single twitches was enhanced in the presence of isoproterenol without interim stimulation (Fig. 4 C, top), accounting for drops in [Ca2+]SR of ∼65 and ∼99 μM in the absence and presence of isoproterenol, respectively; this effect was even stronger upon 50 Hz stimulation, where the corresponding changes were calculated to be ∼83 and ∼153 μM. Third, the kinetics of the Ca2+-release/reuptake ...
Ask the Muscle Doc: Is Sarcoplasmic Hypertrophy Real? - Keto ClusterAsk the Muscle Doc: Is Sarcoplasmic Hypertrophy Real? - Keto Cluster
The researchers put resistance-trained men on a six-week very-high-volume lifting program and then performed biopsies on the subjects vastus lateralis. The results showed a substantial increase in muscle fiber size (greater than 20 percent) that was accompanied by a roughly 30 percent reduction in the proportion of myofibrillar proteins. Those findings suggest that the hypertrophy was due to an increase in sarcoplasmic components (likely a combination of fluid and proteins related to metabolic stress).. Whats really interesting is that follow-up work from the same lab found that a heavier-load, lower-volume protocol resulted in type 2 fiber hypertrophy, but the changes occurred without significant increases in sarcoplasmic proteins and fluid.[5] Collectively, these studies suggest that bodybuilding-type training routines, with higher volume and moderate loads, produce greater increases in sarcoplasmic growth, whereas powerlifting-type programs, with lower volume and heavier loads, may generate ...
Ask the Muscle Doc: Is Sarcoplasmic Hypertrophy Real?Ask the Muscle Doc: Is Sarcoplasmic Hypertrophy Real?
The researchers put resistance-trained men on a six-week very-high-volume lifting program and then performed biopsies on the subjects vastus lateralis. The results showed a substantial increase in muscle fiber size (greater than 20 percent) that was accompanied by a roughly 30 percent reduction in the proportion of myofibrillar proteins. Those findings suggest that the hypertrophy was due to an increase in sarcoplasmic components (likely a combination of fluid and proteins related to metabolic stress).. Whats really interesting is that follow-up work from the same lab found that a heavier-load, lower-volume protocol resulted in type 2 fiber hypertrophy, but the changes occurred without significant increases in sarcoplasmic proteins and fluid.[5] Collectively, these studies suggest that bodybuilding-type training routines, with higher volume and moderate loads, produce greater increases in sarcoplasmic growth, whereas powerlifting-type programs, with lower volume and heavier loads, may generate ...
CURE-PLaN - Cure PhosphoLambaN induced cardiomyopathyCURE-PLaN - Cure PhosphoLambaN induced cardiomyopathy
The sarcoplasmic reticulum (SR) is a membrane-bound structure found within the cardiac muscle cells. Its main function is to regulate the flow of calcium, releasing calcium ions to the surrounding muscle fibers during contraction of the heart muscle and absorbing calcium during relaxation; calcium makes the heart pump. A crucial protein that regulates the function of the SR is phospholamban (PLN); mutations in the PLN gene result in defective PLN which can in turn causes a genetic, or inherited, form of heart failure.. The CURE-PLaN network will focus on one particular mutation that is found in patients in the United States and Europe. Our objective is to understand how patients with the mutation develop heart failure, and why not all patients with the mutation have the same clinical course.. Network scientists will use various models and single muscle cell lines to learn more about the genetics of the disease and how to alter the SR and PLN to make heart muscle cells work more efficiently. This ...
TCDB » SEARCHTCDB » SEARCH
Mitsugumin 23 (MG23), also called TM protein 109 (Venturi et al., 2011). MG23 is a Ca2+ channel protein that is regulated by cytoplasmic Zn2+, and dysregulation of this ion channel plays a role in diastolic sarcoplasmic reticulum Ca2+ homeostasis, promoting leakage from the SR (Reilly-ODonnell et al. 2017 ...
necessary | inguma-framework.orgnecessary | inguma-framework.org
Whatever it was, for a long period of implementation of two-phase muscle activity. ochevidnoj neobhodimo permanent restoration ( re-synthesis) adenosine triphosphate as the muscle it is quickly consumed. As a result of this constant regeneration ( resynthesis) adenosine triphosphate at the expense of other metabolic processes in the number of its muscles at a. moderate work practically does not change. Only at very long and hard work there has been some decrease in the content of ATP in muscle tissue.. From the above data it follows that in the implementation of the two-phase muscle activity plays a very important role in the mechanism of regulation of the sarcoplasmic reticulum content in muscle fibers CA ion. The binding and release of CA ions in the sarcoplasm, probably depends on the change of the potential sarcoplasmatic-ical membranes. The magnitude of the potentials of these membranes, in turn, can very quickly be changed under the influence of nerve impulses.. Continue reading →. ...
blood | inguma-framework.orgblood | inguma-framework.org
Whatever it was, for a long period of implementation of two-phase muscle activity. ochevidnoj neobhodimo permanent restoration ( re-synthesis) adenosine triphosphate as the muscle it is quickly consumed. As a result of this constant regeneration ( resynthesis) adenosine triphosphate at the expense of other metabolic processes in the number of its muscles at a. moderate work practically does not change. Only at very long and hard work there has been some decrease in the content of ATP in muscle tissue.. From the above data it follows that in the implementation of the two-phase muscle activity plays a very important role in the mechanism of regulation of the sarcoplasmic reticulum content in muscle fibers CA ion. The binding and release of CA ions in the sarcoplasm, probably depends on the change of the potential sarcoplasmatic-ical membranes. The magnitude of the potentials of these membranes, in turn, can very quickly be changed under the influence of nerve impulses.. Continue reading →. ...
Regulation of Contraction in Heart Muscle | SpringerLinkRegulation of Contraction in Heart Muscle | SpringerLink
The sarcoplasmic reticulum (SR) in heart muscle releases a large amount of Ca2+ in response to a small amount of trigger Ca2+ by the mechanism of the Ca2+-induced Ca2+-release. A model was presented...
Sarcalumenin Antibody (XIIC4) (NB120-2874): Novus BiologicalsSarcalumenin Antibody (XIIC4) (NB120-2874): Novus Biologicals
Mouse Monoclonal Anti-Sarcalumenin Antibody (XIIC4). Validated: WB, IF. Tested Reactivity: Mouse, Canine, Guinea Pig, and more. 100% Guaranteed.
A 60 kDa polypeptide of skeletal-muscle sarcoplasmic reticulum is a calmodulin-dependent protein kinase that associates with...A 60 kDa polypeptide of skeletal-muscle sarcoplasmic reticulum is a calmodulin-dependent protein kinase that associates with...
Activation of a calmodulin (CaM)-dependent protein kinase associated with rabbit skeletal-muscle sarcoplasmic reticulum (SR) results in the phosphorylation of polypeptides of 450, 360, 165, 105, 89, 60, 34 and 20 kDa. Radioligand-binding studies indicated that a membrane-bound 60 kDa polypeptide contained both CaM- and ATP-binding domains. Under renaturing conditions on nitrocellulose blots, the 60 kDa polypeptide of the membrane exhibited CaM-dependent autophosphorylation activity, suggesting that it was the CaM-dependent protein kinase of SR. Ca2+/CaM-independent autophosphorylation of polypeptides of 62 and 45 kDa was found to occur in the light SR, whereas the Ca2+/CaM-dependent autophosphorylation activity was enriched in the heavy SR. Both these kinase activities were absent from transverse tubules, although these membranes were enriched in CaM-binding polypeptides of 160, 100 and 80 kDa. In the absence of Ca2+, CaM bound to a 33 kDa polypeptide of the membrane. The purified ryanodine ...
The Effect of AICAR Treatment on Sarcoplasmic Reticulum Function and Possible Links to Skeletal Muscle FatigueThe Effect of AICAR Treatment on Sarcoplasmic Reticulum Function and Possible Links to Skeletal Muscle Fatigue
A compelling mystery in the study of exercise is mechanisms of skeletal muscle fatigue. Broadly described, muscle fatigue is the uncomfortable sensation that particular muscle groups are shutting down and muscle force production cannot continue. More specifically, muscle fatigue is defined as an activity-induced inability to continue to produce a desired level of force. Several groups suggest that a major cause of force loss during fatigue is reductions in the rates of sarcoplasmic reticulum (SR) calcium (Ca2+) release and uptake. These changes result in diminished contractile machinery activation, reduced force production and slowed relaxation. During exercise, adenosine 5-triphosphate (ATP) is the energy currency that is used to support force production. As a result of ATP hydrolysis and re-synthesis, adenosine diphosphate (ADP) and adenosine monophosphate (AMP) levels rise. AMP kinase (AMPK) is an enzyme that becomes activated as a result of increased AMP levels. It is thought to function as ...
Casq2 deletion causes sarcoplasmic reticulum volume increase, premature Ca<sup>2+</sup> release, and catecholaminergic...Casq2 deletion causes sarcoplasmic reticulum volume increase, premature Ca<sup>2+</sup> release, and catecholaminergic...
TY - JOUR. T1 - Casq2 deletion causes sarcoplasmic reticulum volume increase, premature Ca2+ release, and catecholaminergic polymorphic ventricular tachycardia. AU - Knollmann, Björn C.. AU - Chopra, Nagesh. AU - Hlaing, Thinn. AU - Akin, Brandy. AU - Yang, Tao. AU - Ettensohn, Kristen. AU - Knollmann, Barbara E.C.. AU - Horton, Kenneth D.. AU - Weissman, Neil J.. AU - Holinstat, Izabela. AU - Zhang, Wei. AU - Roden, Dan M.. AU - Jones, Larry R.. AU - Franzini-Armstrong, Clara. AU - Pfeifer, Karl. PY - 2006/9/1. Y1 - 2006/9/1. N2 - Cardiac calsequestrin (Casq2) is thought to be the key sarcoplasmic reticulum (SR) Ca2+ storage protein essential for SR Ca2+ release in mammalian heart. Human CASQ2 mutations are associated with catecholaminergic ventricular tachycardia. However, homozygous mutation carriers presumably lacking functional Casq2 display surprisingly normal cardiac contractility. Here we show that Casq2-null mice are viable and display normal SR Ca2+ release and contractile function ...
Conformational Transitions and Alternating-Access Mechanism in the Sarcoplasmic Reticulum Calcium Pump | Membrane Protein...Conformational Transitions and Alternating-Access Mechanism in the Sarcoplasmic Reticulum Calcium Pump | Membrane Protein...
Ion pumps are integral membrane proteins responsible for transporting ions against concentration gradients across biological membranes. Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), a member of the P-type ATPases family, transports two calcium ions per hydrolyzed ATP molecule via an "alternating-access" mechanism. High-resolution crystallographic structures provide invaluable insight on the structural mechanism of the ion pumping process. However, to understand the molecular details of how ATP hydrolysis is coupled to calcium transport, it is necessary to gain knowledge about the conformational transition pathways connecting the crystallographically resolved conformations. Large-scale transitions in SERCA occur at time-scales beyond the current reach of unbiased molecular dynamics simulations. Here, we overcome this challenge by employing the string method, which represents a transition pathway as a chainofstates linking two conformational endpoints. Using a multiscale methodology, we have ...
Cryo-electron microscopy and three-dimensional reconstruction of the calcium release channel/ryanodine receptor from skeletal...Cryo-electron microscopy and three-dimensional reconstruction of the calcium release channel/ryanodine receptor from skeletal...
The calcium release channel (CRC) from skeletal muscle is an unusually large tetrameric ion channel of the sarcoplasmic reticulum, and it is a major component of the triad junction, the site of excitation contraction coupling. The three-dimensional architecture of the CRC was determined from a random conical tilt series of images extracted from electron micrographs of isolated detergent-solubilized channels prepared in a frozen-hydrated state. Three major classes of fourfold symmetric images were identified, and three-dimensional reconstructions were determined for two of these. The two independent reconstructions were almost identical, being related to each other by a 180 degrees rotation about an axis in the plane of the specimen grid. The CRC consists of a large cytoplasmic assembly (29 x 29 x 12 nm) and a smaller transmembrane assembly that protrudes 7 nm from one of its faces. A cylindrical low-density region, 2-3 nm in apparent diameter, extends down the center of the transmembrane ...
Novel use of glycosylation scanning to map the intracellular trafficking of sarco(endo)plasmic reticulum calcium ATPase 1ANovel use of glycosylation scanning to map the intracellular trafficking of sarco(endo)plasmic reticulum calcium ATPase 1A
The sarco(endo)plasmic reticulum calcium ATPase (SERCA) family of proteins function as calcium pumps in the endoplasmic reticulum (ER) and sarcoplasmic reticulum (SR) membranes. SERCA1a is found exclusively in fast-twitch muscle cells and mediates muscle relaxation by pumping calcium back into the SR after calcium has been released into the cytoplasm to elicit muscle contraction. The mechanism which allows SR biogenesis is not known, but SR membrane is believed to bud from the ER. One hypothesis is that SERCA1a proteins play a significant role in SR biogenesis in fast-twitch skeletal muscle due the proteins large size and clustering into large arrays in the SR membrane. SERCA1a arrays could recruit lipids which would allow for a large increase in membrane size that could result in the formation of the SR. Also, SERCA1a is highly expressed during the early stages of myogenesis, at the same time the first emergence of the SR is observed. It is known that SERCA1a contains ER targeting information ...
Triadin - WikipediaTriadin - Wikipedia
Triadin, also known as TRDN, is a human gene associated with the release of Calcium ions from the sarcoplasmic reticulum triggering muscular contraction through calcium-induced calcium release. Triadin is a multiprotein family, arising from different processing of the TRDN gene on chromosome 6. It is a transmembrane protein on the sarcoplasmic reticulum due to a well defined hydrophobic section and it forms a quaternary complex with the cardiac Ryanodine receptor (RYR2), calsequestrin (CASQ2) and junctin proteins. The luminal (inner compartment of the sarcoplasmic reticulum) section of Triadin has areas of highly charged amino acid residues that act as luminal Ca2+ receptors. Triadin is also able to sense luminal Ca2+ concentrations by mediating interactions between RYR2 and CASQ2. Triadin has several different forms; Trisk 95 and Trisk 51, which are expressed in skeletal muscle, and Trisk 32 (CT1), which is mainly expressed in cardiac muscle. TRDN has been shown to interact with RYR1. Triadin ...
Transmembrane Ca2+ gradient-mediated change of fluidity in the inner layer of phospholipids modulates Ca2+-ATPase of...Transmembrane Ca2+ gradient-mediated change of fluidity in the inner layer of phospholipids modulates Ca2+-ATPase of...
TY - JOUR. T1 - Transmembrane Ca2+ gradient-mediated change of fluidity in the inner layer of phospholipids modulates Ca2+-ATPase of sarcoplasmic reticulum. AU - Tu, Yaping. AU - Xu, H.. AU - Yang, F. Y.. PY - 1994. Y1 - 1994. N2 - Sarcoplasmic reticulum (SR) vesicles with (1000 folds) or without transmembrane Ca2+ gradient have been prepared. Different fluorescence probes (DPH, TMA-DPH and n-AS), were used to determine the effect of transmembrane Ca2+ gradient on the lipid fluidity both in outer and inner layer of Ca2+-ATPase-containing SR vesicles. The results showed that transmembrane Ca2+ gradient could significantly decrease the fluidity of the inner layer of SR membrane, while no obvious change was monitored in the outer layer. This may be deduced that Ca2+-ATPase might be modulated mainly by the transmembrane Ca2+ gradient-mediated alteration of physical state of phospholipid in the inner layer of SR membrane.. AB - Sarcoplasmic reticulum (SR) vesicles with (1000 folds) or without ...
Regulation of sarco(endo)plasmic reticulum Ca2+-ATPase and calseq...: Ingenta ConnectRegulation of sarco(endo)plasmic reticulum Ca2+-ATPase and calseq...: Ingenta Connect
The precise control of Ca2+ levels during the contraction-relaxation cycle in cardiac myocytes is extremely important for normal beat-to-beat contractile activity. The sarcoplasmic reticulum (SR) plays a key role controlling calcium concentration in the cytosol. The SR Ca2+-ATPase (SERCA2) transports Ca2+ inside the SR lumen during relaxation of the cardiac myocyte. Calsequestrin (Casq2) is the main protein in the SR lumen, functioning as a Ca2+ buffer and participating in Ca2+ release by interacting with the ryanodine receptor 2 (RyR2) Ca2+-release channel. Alterations in normal Ca2+ handling significantly contribute to the contractile dysfunction observed in cardiac hypertrophy and in heart failure. Transcriptional regulation of the SERCA2 gene has been extensively studied and some of the mechanisms regulating its expression have been elucidated. Overexpression of Sp1 factor in cardiac hypertrophy downregulates SERCA2 gene expression and increased levels of thyroid hormone up-regulates its ...
Sarcoplasmic reticulum calcium leak contributes to arrhythmia but not to heart failure progression | Science Translational...Sarcoplasmic reticulum calcium leak contributes to arrhythmia but not to heart failure progression | Science Translational...
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Synergistic dual automaticity in sinoatrial node cell and tissue models<...Synergistic dual automaticity in sinoatrial node cell and tissue models<...
TY - JOUR. T1 - Synergistic dual automaticity in sinoatrial node cell and tissue models. AU - Zhang, Hong. AU - Joung, Boyoung. AU - Shinohara, Tetsuji. AU - Mei, Xi. AU - Chen, Peng-Sheng. AU - Lin, Shien-Fong. PY - 2010. Y1 - 2010. N2 - Background: The mechanism of sinoatrial node (SAN) automaticity is traditionally attributed to membrane ion currents. Recent evidence indicates spontaneous sarcoplasmic reticulum (SR) Ca2+ cycling also plays an important role. Methods and Results: A computer simulation on SAN cell and 1D tissue model was performed. In the SAN cells, SR Ca2+ cycling broadly modulated the sinus rate from 1.74 Hz to 3.87 Hz. Shortening of the junctional SR refilling time and increase of SR Ca2+ release were responsible for sinus rate acceleration. However, under the fast SR Ca2+ cycling, decreased L-type Ca2+ current (ICaL) resulted in irregular firing. When Ca2+ cycling was suppressed, If and ICaT both acted to stabilize the pacemaker rhythm, but ICaT had less effect than If. At ...
Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular...Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular...
Intracellular calcium recycling plays a critical role in regulation of systolic and diastolic function in cardiomyocytes. Here, we...
KEGG PATHWAY: Cardiac muscle contraction - Homo sapiens (human)KEGG PATHWAY: Cardiac muscle contraction - Homo sapiens (human)
Contraction of the heart is a complex process initiated by the electrical excitation of cardiac myocytes (excitation-contraction coupling, ECC). In cardiac myocytes, Ca2+ influx induced by activation of voltage-dependent L-type Ca channels (DHP receptors) upon membrane depolarization triggers the release of Ca2+ via Ca2+ release channels (ryanodine receptors) of sarcoplasmic reticulum (SR) through a Ca2+ -induced Ca release (CICR) mechanism. Ca2+ ions released via the CICR mechanism diffuse through the cytosolic space to contractile proteins to bind to troponinC resulting in the release of inhibition induced by troponinI. The Ca2+ binding to troponinC thereby triggers the sliding of thin and thick filaments, that is, the activation of a crossbridge and subsequent cardiac force development and/or cell shortening. Recovery occurs as Ca2+ is pumped out of the cell by the Na+/Ca2+ exchanger (NCX) or is returned to the sarcoplasmic reticulum (SR) by sarco(endo)plasmic Ca2+ -ATPase (SERCA) pumps on ...
NAVER 학술정보 | Ameliorated stress related proteins are associated with improved cardiac function by sarcoplasmic reticulum...NAVER 학술정보 | Ameliorated stress related proteins are associated with improved cardiac function by sarcoplasmic reticulum...
Backgrounds Previous studies showed that overexpression of sarco-endoplasmic reticulum calcium ATPase (SERCA2a) in a variety of heart failure (HF) models was associated with greatly enhanced cardiac performance. However, it still undefined the effect of SERCA2a overexpression on the systemic inflammatory response and neuro-hormonal factors. Methods A rapid right ventricular pacing model of experimental HF was used in beagles. Then the animals underwent recombinant adeno-associated virus 1 (rAAV1) mediated gene trans¬fection by direct intra-myocardium injection. HF animals were randomized to receive the SERCA2a gene, enhanced green fluorescent protein (control) gene, or equivalent phosphate buffered saline. Thirty days after gene delivery, the cardiac function was evaluated by echocardiographic testing. The protein level of SERCA2a was measured by western blotting. The proteomic analysis of left ventricular (LV) sample was determined using two-dimensional (2-D) gel electrophoresis and MALDI-TOF-MS. The
University of Pennsylvania || School of Medicine || Stephen M. Baylor, M.D.University of Pennsylvania || School of Medicine || Stephen M. Baylor, M.D.
Areas of active investigation include: use of laser-scanning confocal microscopy to measure "calcium sparks", which are brief localized increases in fluorescence from a Ca-indicator such as fluo-3 that are thought to be reflective of the transient opening of one or a few RyRs (=ryanodine receptors), the Ca release channels of the sarcoplasmic reticulum (SR); the possibility that the mechanism of activation of RyRs involves both voltage-gating and Ca-gating; the nature of the mechanism whereby SR Ca release is inactivated by a rise in myoplasmic free [Ca]; the possibility that either activation or inactivation of SR Ca release may vary with the RyR isoform composition (RyR1, RyR3, etc.); estimation of local Ca movements within the sarcomere by means of computer modeling, including estimation of the kinetics of binding of Ca to the intracellular Ca buffers troponin, parvalbumin, ATP, and the SR Ca pump ...
ADCY6 gene - Genetics Home ReferenceADCY6 gene - Genetics Home Reference
Catalyzes the formation of the signaling molecule cAMP downstream of G protein-coupled receptors (PubMed:17916776, PubMed:17110384). Functions in signaling cascades downstream of beta-adrenergic receptors in the heart and in vascular smooth muscle cells (PubMed:17916776). Functions in signaling cascades downstream of the vasopressin receptor in the kidney and has a role in renal water reabsorption. Functions in signaling cascades downstream of PTH1R and plays a role in regulating renal phosphate excretion. Functions in signaling cascades downstream of the VIP and SCT receptors in pancreas and contributes to the regulation of pancreatic amylase and fluid secretion (By similarity). Signaling mediates cAMP-dependent activation of protein kinase PKA. This promotes increased phosphorylation of various proteins, including AKT. Plays a role in regulating cardiac sarcoplasmic reticulum Ca(2+) uptake and storage, and is required for normal heart ventricular contractibility. May contribute to normal heart ...
Vasostatin, a Calreticulin Fragment, Inhibits Angiogenesis and Suppresses Tumor Growth | JEMVasostatin, a Calreticulin Fragment, Inhibits Angiogenesis and Suppresses Tumor Growth | JEM
These results show that vasostatin, an NH2-terminal fragment of human calreticulin, can inhibit endothelial cell proliferation in vitro, suppress neovascularization in vivo, and prevent or reduce growth of experimental tumors. Calreticulin, a ubiquitous and highly conserved protein originally identified in skeletal muscle sarcoplasmic reticulum, serves as one of the major storage depots for calcium ions within the endoplasmic reticulum and participates in calcium signaling ((34)-(36)). The NH2-domain of calreticulin, which includes aa 1-180, is the most conserved domain among the calreticulins so far cloned and has no homology to other protein sequences ((34), (35)). Although it does not bind calcium, it can bind the cytoplasmic domain of α subunits of integrins regulating cell attachment ((37)), can interact with the nuclear receptors for glucocorticoid, androgen, and retinoic acid, regulating their binding to DNA ((38)), and can, once phosphorylated, bind stem-loop structures at the 3′-end ...
Muscle Fibres - Revision Cards in A Level and IB BiologyMuscle Fibres - Revision Cards in A Level and IB Biology
Muscle Contraction When a action potential arrives via a motor neurone to the muscle - it depolarizes the transverse tubules, which triggers calcium to be released from the sarcoplasmic reticulum by the opening of calcium channels in the sarcoplasmic reticulum membrane.. The calcium ions bind with the troponin molecules on the actin filaments - causing them to change shape, this causes the tropomyosin to move, exposing a site that the myosin can bind to.. The myosin then quickly tilts through 45 degrees - so the actin gets pulled towards the centre of the sacromere. As teh head tilts the ADP and Pi are released, and an ATP molecule takes their place.. The myosin head then hydrolyses the ATP to ADP and Pi - the energy generated from this is used to detach the myosin head from the actin filament. The cycle then starts all over again!. ...
Physiological function of myotonin protein kinase]. - Semantic ScholarPhysiological function of myotonin protein kinase]. - Semantic Scholar
The mutation underlying myotonic dystrophy is the expansion of polymorphic CTG repeat in the 3-noncoding region of the myotonin protein kinase (MtPK) gene mapping to chromosome 19q13.3. A full-length cDNA of human MtPK was cloned and expressed in COS-1 cells. We purified native full-length MtPK from rat skeletal muscle. This 70 kDa MtPK is localized in sarcoplasmic reticulum fraction, whereas the previously reported 55 kDa protein was observed in nuclear extract or the sarcoplasmic reticulum membrane. Based on the cDNA sequence, human MtPK was previously reported to have two amino acid sequence variations at the C-terminus, one GAARAP (RAP type) and PALPEP (PEP type). The MtPK purified appeared to be almost entirely RAP type. Stable expression of MtPK in mouse C2C12 cells caused the activation of chloride efflux. Expansion of CTG repeats suppressed myogenic differentiation. Collectively, the results indicate that prolonged MtPK activation provides a link between intracellular signal transduction
Calcium Pumps - Stock Video Clip K005/0663 - Science Photo LibraryCalcium Pumps - Stock Video Clip K005/0663 - Science Photo Library
Calcium pumps transport calcium back into sarcoplasmic reticulum, ending an action potential and causing relaxation. The process of muscle contraction will continue until the action potential is terminated. Relaxation is achieved when calcium pumps have actively transported calcium back into the sarcoplasmic reticulum, reversing the changes that previously occurred in troponin. Tropomyosin is now back in its original position covering the myosin binding sites on actin, preventing crossbridges and power stroke cycling. - Stock Video Clip K005/0663
The endoplasmic reticulum and junctional membrane communication during calcium signaling - Department of PharmacologyThe endoplasmic reticulum and junctional membrane communication during calcium signaling - Department of Pharmacology
The endoplasmic reticulum is a major organelle in all eukaryotic cells which performs multiple functions including protein and lipid synthesis and sorting, drug metabolism, and Ca 2+ storage and release. The endoplasmic reticulum, and its specialized muscle counterpart the sarcoplasmic reticulum, is the largest and most extensive of Ca 2+ storage organelle in eukaryotic cells, often occupying in excess of 10% of the cell volume. There are three major components of Ca 2+ storage organelles which mediate their major functions: Ca 2+ uptake, mediated by pumps and exchangers; storage enhanced by luminal Ca 2+ binding proteins, and Ca 2+ mobilization mediated by specific ion channels. Ca 2+ mobilization from the endoplasmic reticulum plays a central role in Ca 2+ signaling. Through Ca 2+ release channels in its membrane, the pervading and plastic structure of the endoplasmic reticulum allows Ca 2+ release to be rapidly targeted to specific cytoplasmic sites across the whole cell. That several
AbstractAbstract
Author: P. SATHYAVATHI. Category: Physiology. [Download PDF]. Abstract:. Background and objectives: Calcium is the prime mediator of the contractile mechanism in frog ventricle. Sarcoplasmic reticulum (SR) releases calcium by a well-known calcium induced calcium release (CICR) mechanism. CICR is mediated by ryanodine receptor (RyR) and inositol 1,4, 5- triphosphate (IP3) receptors on the SR membrane. This increase in cytosolic calcium concentration causes contraction of the cardiac muscle. Aim :The study aims at examining the interdependent role of the known calcium release channels on the SR in frog ventricle. Materials and Methods and the Study Design: Isolated ventricular strips of frogs (rana hexadactyla) were used for the study. The study design includes subjecting the ventricular strip to continuous electrical stimulation with imposed rest periods intermittently to examine the diastolic depletion of calcium from the SR. The magnitude of decay of the post rest amplitude in relation to the ...
SMART: Pfam domain CalsequestrinSMART: Pfam domain Calsequestrin
Calsequestrin is the principal calcium-binding protein present in the sarcoplasmic reticulum of cardiac and skeletal muscle [(PUBMED:3379055)]. It is a highly acidic protein that is able to bind over 40 calcium ions and acts as an internal calcium store in muscle. Sequence analysis has suggested that calcium is not bound in distinct pockets via EF-hand motifs, but rather via presentation of a charged protein surface. Two forms of calsequestrin have been identified. The cardiac form is present in cardiac and slow skeletal muscle and the fast skeletal form is found in fast skeletal muscle. The release of calsequestrin-bound calcium (through a a calcium release channel) triggers muscle contraction. The active protein is not highly structured, more than 50% of it adopting a random coil conformation [(PUBMED:3427023)]. When calcium binds there is a structural change whereby the alpha-helical content of the protein increases from 3 to 11% [(PUBMED:3427023)]. Both forms of calsequestrin are ...
PLN - Cardiac phospholamban - Bos taurus (Bovine) - PLN gene & proteinPLN - Cardiac phospholamban - Bos taurus (Bovine) - PLN gene & protein
Reversibly inhibits the activity of ATP2A2 in cardiac sarcoplasmic reticulum by decreasing the apparent affinity of the ATPase for Ca(2+). Modulates the contractility of the heart muscle in response to physiological stimuli via its effects on ATP2A2. Modulates calcium re-uptake during muscle relaxation and plays an important role in calcium homeostasis in the heart muscle. The degree of ATP2A2 inhibition depends on the oligomeric state of PLN. ATP2A2 inhibition is alleviated by PLN phosphorylation (By similarity).
Reconstitution of a Ca2+-transporting ATPase system from triton X-100-solubilized sarcoplasmic reticulum. - ImmunologyReconstitution of a Ca2+-transporting ATPase system from triton X-100-solubilized sarcoplasmic reticulum. - Immunology
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Molecular Basis and Regulation of Ca2+ Release Termination and its Role in CardiomyopathiesMolecular Basis and Regulation of Ca2+ Release Termination and its Role in Cardiomyopathies
It is known that sarcoplasmic reticulum (SR) Ca2+ release in cardiac muscle is initiated via cardiac ryanodine receptor (RyR2) through a mechanism called Ca2+-induced Ca2+ release. However, how the SR Ca2+ release is terminated is undetermined. The objective of the current study is to understand the molecular basis and regulation of RyR2-mediated Ca2+ release termination and its role in the pathogenesis of cardiac diseases. Based on recent 3D structural analyses, the NH2-terminal region of RyR2 interacts with the channel domain via the central domain and undergoes dynamic conformational changes during channel gating. It has also been discovered that the NH2-terminal region consists of three distinct domains. HEK293 cell studies on domain deletions and disease mutations demonstrate that the different domains play different roles in RyR2 function. The NH2-terminal region is a major determinant of Ca2+ release activation and termination. Enhanced luminal Ca2+ activation of RyR2 has been linked to ...
mouse Asph protein Summary Report | CureHuntermouse Asph protein Summary Report | CureHunter
mouse Asph protein: 26-kDa protein isolated from cardiac junctional sarcoplasmic reticulum; hydroxylates ASP or ASN residues in EGF domains of some proteins; RefSeq NM_023066
JCI - Human phospholamban null results in lethal dilated cardiomyopathy revealing a critical difference between mouse and humanJCI - Human phospholamban null results in lethal dilated cardiomyopathy revealing a critical difference between mouse and human
In human disease and experimental animal models, depressed Ca2+ handling in failing cardiomyocytes is widely attributed to impaired sarcoplasmic reticulum (SR) function. In mice, disruption of the PLN gene encoding phospholamban (PLN) or expression of dominant-negative PLN mutants enhances SR and cardiac function, but effects of PLN mutations in humans are unknown. Here, a T116G point mutation, substituting a termination codon for Leu-39 (L39stop), was identified in two families with hereditary heart failure. The heterozygous individuals exhibited hypertrophy without diminished contractile performance. Strikingly, both individuals homozygous for L39stop developed dilated cardiomyopathy and heart failure, requiring cardiac transplantation at ages 16 and 27. An over 50% reduction in PLN mRNA and no detectable PLN protein were noted in one explanted heart. The expression of recombinant PLN-L39stop in human embryonic kidney (HEK) 293 cells and adult rat cardiomyocytes showed no PLN inhibition of SR ...
JCI - Human phospholamban null results in lethal dilated cardiomyopathy revealing a critical difference between mouse and humanJCI - Human phospholamban null results in lethal dilated cardiomyopathy revealing a critical difference between mouse and human
In human disease and experimental animal models, depressed Ca2+ handling in failing cardiomyocytes is widely attributed to impaired sarcoplasmic reticulum (SR) function. In mice, disruption of the PLN gene encoding phospholamban (PLN) or expression of dominant-negative PLN mutants enhances SR and cardiac function, but effects of PLN mutations in humans are unknown. Here, a T116G point mutation, substituting a termination codon for Leu-39 (L39stop), was identified in two families with hereditary heart failure. The heterozygous individuals exhibited hypertrophy without diminished contractile performance. Strikingly, both individuals homozygous for L39stop developed dilated cardiomyopathy and heart failure, requiring cardiac transplantation at ages 16 and 27. An over 50% reduction in PLN mRNA and no detectable PLN protein were noted in one explanted heart. The expression of recombinant PLN-L39stop in human embryonic kidney (HEK) 293 cells and adult rat cardiomyocytes showed no PLN inhibition of SR ...
Jafri, Rice, Winslow, 1998 - Physiome Model RepositoryJafri, Rice, Winslow, 1998 - Physiome Model Repository
ABSTRACT: We construct a detailed mathematical model for Ca2+ regulation in the ventricular myocyte that includes novel descriptions of subcellular mechanisms based on recent experimental findings: 1) the Keizer-Levine model for the ryanodine receptor (RyR), which displays adaptation at elevated Ca2+; 2) a model for the L-type Ca2+ channel that inactivates by mode switching; and 3) a restricted subspace into which the RyRs and L-type Ca2+ channels empty and interact via Ca2+. We add membrane currents from the Luo-Rudy Phase II ventricular cell model to our description of Ca2+ handling to formulate a new model for ventricular action potentials and Ca2+ regulation. The model can simulate Ca2+ transients during an action potential similar to those seen experimentally. The subspace [Ca2+] rises more rapidly and reaches a higher level (10-30 microM) than the bulk myoplasmic Ca2+ (peak [Ca2+]i approximately 1 microM). Termination of sarcoplasmic reticulum (SR) Ca2+ release is predominately due to ...
Plus itPlus it
The ERRα transcriptional pathway has been shown in recent years to play a central role in the regulation of mitochondrial energy metabolism in many cell and tissue types, including striated muscle (20, 63). In the present study, we explored the hypothesis that ERRα may function more broadly as an essential regulatory component of myogenesis. Myocyte differentiation requires precise regulation of multiple gene programs, consisting of genes encoding contractile and sarcoplasmic reticulum proteins, along with ubiquitously expressed proteins involved in energy metabolism. Such coordination may be mediated by transcriptional regulators of energy metabolism genes, including the ERR isoforms and their PGC-1 coactivators, that are temporally induced as part of the myogenic program (Refs. 28, 66; present study). Our findings suggest that ERRα does promote differentiation when overexpressed and is required for normal myogenesis. A surprising finding was that the broader regulatory function for ERRα in ...
Calcium Pump - Stock Image C017/6296 - Science Photo LibraryCalcium Pump - Stock Image C017/6296 - Science Photo Library
A molecular ribbon model of a calcium pump, a structure responsible for coordinating muscular contraction or signalling other cells along the cell membrane. Calcium pumps are embedded in the sarcoplasmic reticulum of muscle cells, transferring two calcium ions for each molecule of ATP broken down. - Stock Image C017/6296
Structure and Topology of Phospholamban Monomer and Pentamer by a Hybrid Solution and Solid-State NMR MethodStructure and Topology of Phospholamban Monomer and Pentamer by a Hybrid Solution and Solid-State NMR Method
Phospholamban (PLN) is an integral membrane protein that regulates calcium homeostasis by inhibiting sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) in cardiac muscle. PLN exists in two primary oligomeric forms: (1) a monomer that directly bind
Anion specific carriers in the sarcoplasmic membranes :: MPG.PuReAnion specific carriers in the sarcoplasmic membranes :: MPG.PuRe
Author: Hasselbach, Wilhelm et al.; Genre: Book Chapter; Published in Print: 1974; Title: Anion specific carriers in the sarcoplasmic membranes
BIO-SYNTHESIS - Custom Antibody Custom Peptide Synthesis Custom SiRNA Synthesis: JPH3 AntibodyBIO-SYNTHESIS - Custom Antibody Custom Peptide Synthesis Custom SiRNA Synthesis: JPH3 Antibody
Junctional complexes between the plasma membrane (PM) and endoplasmic/sarcoplasmic reticulum (ER/SR) are a common feature of all excitable cell types and mediate cross talk between cell surface and intracellular ion channels. Junctophilins (JPs) are important components of the junctional complexes. JPs are composed of a carboxy-terminal hydrophobic segment spanning the ER/SR membrane and a remaining cytoplasmic domain that shows specific affinity for the PM. Four JPs have been identified as tissue-specific subtypes derived from different genes: JPH1 is expressed in skeletal muscle, JPH2 is detected throughout all muscle cell types, and JPH3 and JPH4 are predominantly expressed in the brain. In the CNS, both JPH3 and JPH4 are expressed throughout neural sites and contribute to the subsurface cistern formation in neurons. Mice lacking both JPH3 and JPH4 subtypes exhibit serious symptoms such as impaired learning and memory and are accompanied by abnormal nervous functions. A repeat expansion in ...
Search Results (204) | Profiles RNSSearch Results (204) | Profiles RNS
Calcium Upregulation by Percutaneous Administration of Gene Therapy in Cardiac Disease (CUPID): a phase 2 trial of intracoronary gene therapy of sarcoplasmic reticulum Ca2+-ATPase in patients with advanced heart failure ...
Physio I Block 4Physio I Block 4
A: 1. by increasing open time of the calcium channels, and more calcium rush into the cardiac muscle cell. From the extracellular fluid. 2. Phosphorylate (activate) phospholamban, whch increases Calcium ATPase in the sarcoplasmic reticulum. This increases calcium stores in the SR, so more is released when needed, leading to forceful contractions. Calcium is also removed from the cytosol faster, shortening the calcium-troponin binding time, which causes shorter duration of contraction.. Q: What is the isovolumic systole ...
Biological membraneBiological membrane
David W. DeamerDavid W. Deamer
Calcium-induced calcium releaseCalcium-induced calcium release
ActinActin
Catecholaminergic polymorphic ventricular tachycardiaCatecholaminergic polymorphic ventricular tachycardia
Asynchronous musclesAsynchronous muscles
ASPHASPH
Negative stainNegative stain
Sodium-calcium exchangerSodium-calcium exchanger
IstaroximeIstaroxime
ATP2A1ATP2A1
TriadinTriadin
SERCASERCA
Muscle contractionMuscle contraction
Arnold Martin KatzArnold Martin Katz
Calcium sparksCalcium sparks
Calcium ATPaseCalcium ATPase
CalsequestrinCalsequestrin
Emilio VerattiEmilio Veratti
AKAP6AKAP6
Reduced muscle mass, strength and performance in spaceReduced muscle mass, strength and performance in space
SarcolipinSarcolipin
Discovery and development of beta-blockersDiscovery and development of beta-blockers
HRC (gene)HRC (gene)
Cardiac action potentialCardiac action potential
P-type ATPaseP-type ATPase
Psoas major musclePsoas major muscle
Muscular systemMuscular system
1-alkylglycerophosphocholine O-acyltransferase1-alkylglycerophosphocholine O-acyltransferase
Ryanodine-Inositol 1,4,5-triphosphate receptor calcium channelsRyanodine-Inositol 1,4,5-triphosphate receptor calcium channels
Endoplasmic reticulum - Simple English Wikipedia, the free encyclopediaEndoplasmic reticulum - Simple English Wikipedia, the free encyclopedia
Muscle spindleMuscle spindle
Muscle - Simple English Wikipedia, the free encyclopediaMuscle - Simple English Wikipedia, the free encyclopedia
Atrial fibrillationAtrial fibrillation
PerimysiumPerimysium
MyofilamentMyofilament
VasoconstrictionVasoconstriction
Reticulum endoplasmic - WikipèdiaReticulum endoplasmic - Wikipèdia
Reticwlwm endoplasmig - WicipediaReticwlwm endoplasmig - Wicipedia
DigoxinDigoxin
ITPR2 - Wikipédia, a enciclopédia livreITPR2 - Wikipédia, a enciclopédia livre
Intrafusal muscle fiberIntrafusal muscle fiber
Protein kinase AProtein kinase A
MyocyteMyocyte
Physiological cross-sectional areaPhysiological cross-sectional area
T-tubuleT-tubule
TriadTriad
RyanodineRyanodine
Exercise physiologyExercise physiology
Voltage-gated calcium channelVoltage-gated calcium channel
Skeletal muscleSkeletal muscle
endoplasmic reticulumendoplasmic reticulum
OsmiumOsmium
Muscle tissueMuscle tissue
Sarcoplasmic reticulumSarcoplasmic reticulum
Biological membraneBiological membrane
Muscle relaxantMuscle relaxant
HypomagnesemiaHypomagnesemia
AnatomyOrganismsDiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPhenomena and ProcessesDisciplines and OccupationsTechnology, Industry, AgricultureInformation ScienceHealth Care
Sarcoplasmic ReticulumCalcium-Transporting ATPasesSarcoplasmic Reticulum Calcium-Transporting ATPasesCalciumEndoplasmic ReticulumRyanodine Receptor Calcium Release ChannelRabbitsCaffeineCalsequestrinRyanodineMusclesMyocardiumCalcium-Binding ProteinsCa(2+) Mg(2+)-ATPaseMyocardial ContractionCalcium SignalingCalcium ChannelsAdenosine TriphosphateRuthenium RedMuscle ProteinsKineticsMyocytes, CardiacMuscle, SkeletalSodium-Calcium ExchangerMagnesiumThapsigarginAdenosine TriphosphatasesExcitation Contraction CouplingEgtazic AcidMuscle ContractionSarcolemmaCalcium Channels, L-TypeMicrosomesTetracaineHeart VentriclesProcaineMuscle Fibers, SkeletalMyofibrilsDantroleneOxalatesBiological Transport, ActiveDogsHeartIntracellular MembranesMalignant HyperthermiaMicroscopy, ElectronMembrane PotentialsEndoplasmic Reticulum StressPhosphorylationVanadiumFluorescent DyesMurexideBiological TransportHydrogen-Ion ConcentrationMuscle Fibers, Fast-TwitchCalcium RadioisotopesXanthenesIndolesBinding SitesEndoplasmic Reticulum, RoughNaphthalenesulfonatesVanadatesMembranesPapillary MusclesLasalocidPotassiumAdenosine DiphosphateFluorescein-5-isothiocyanatePhosphatesAction PotentialsMembrane ProteinsHalothaneTime FactorsIon TransportProtein BindingIsoproterenolSpectrometry, FluorescenceAequorinCytosolRana pipiensAmino Acid SequenceCalcium Channel BlockersVentricular FunctionMolecular Sequence DataStrontiumElectric StimulationProtein ConformationCells, CulturedInositol 1,4,5-Trisphosphate ReceptorsGuinea PigsMicroscopy, ConfocalFreeze FracturingTacrolimus Binding ProteinsLanthanumSaponinsEndoplasmic Reticulum, SmoothCalcium-Calmodulin-Dependent Protein Kinase Type 2TerpenesMuscle CellsLipid BilayersHydrolysisPotassium ChloridePatch-Clamp TechniquesAniline CompoundsCalreticulinGolgi ApparatusCell MembraneModels, BiologicalCalcium Channel AgonistsSodiumCell FractionationRats, WistarFura-2Tacrolimus Binding Protein 1AIon Channel GatingElectric ConductivityCresolsEnzyme InhibitorsOsmolar ConcentrationBuffersRanidaeCardiomegalyCalmodulinAdrenergic beta-AgonistsElectrophysiologyAnuraRats, Sprague-DawleyAdenylyl ImidodiphosphateIon ChannelsMitochondria, MuscleCytoplasmArrhythmias, CardiacHeart FailurePhosphodiesterase InhibitorsCalcium ChlorideTrypsinAlkaloidsProteolipidsHeart AtriaThymolFluorescamineSilver NitrateMuscle, SmoothDetergentsDose-Response Relationship, DrugBufo marinusFerretsThiocyanatesThiazepinesSulfhydryl CompoundsSodium-Potassium-Exchanging ATPaseMetals, Rare EarthMathematicsReceptors, CholinergicMolecular WeightMuscle Fibers, Slow-TwitchTetraphenylborateOrganophosphatesSwineMuscle FatigueDithiothreitolHomeostasisTemperatureModels, CardiovascularCalcimycinOxalic AcidElectrophoresis, Polyacrylamide GelNifedipineChelating AgentsMaleimidesRana temporariaCarrier ProteinsInositol 1,4,5-TrisphosphateMuscle Relaxants, CentralPermeabilityPhospholipidsTrifluoperazineCardiotonic AgentsCell LineSubcellular FractionsMuscle, Smooth, VascularReticulumMitochondria, HeartMutationMagnesium ChlorideCyclic AMP-Dependent Protein KinasesTerbiumCell Membrane PermeabilityBlotting, WesternRana catesbeianaReceptors, Adrenergic, betaPeptide FragmentsProtein TransportBoron CompoundsFluoresceinsIntracellular FluidSarcomeresEthylmaleimideEtiocholanoloneUnfolded Protein ResponseHistological Techniques
Sarcoplasmic Reticulum | Technology TrendsSarcoplasmic Reticulum | Technology Trends
The Development of the Sarcoplasmic Reticulum (ebook) by Anthony Martonosi | 9781482283624The Development of the Sarcoplasmic Reticulum (ebook) by Anthony Martonosi | 9781482283624
Effects of sarcoplasmic reticulum calcium pump inhibitors on vascular smooth muscle. | HypertensionEffects of sarcoplasmic reticulum calcium pump inhibitors on vascular smooth muscle. | Hypertension
Assembly and dynamics of proteins of the longitudinal and junctional sarcoplasmic reticulum in skeletal muscle cells | PNASAssembly and dynamics of proteins of the longitudinal and junctional sarcoplasmic reticulum in skeletal muscle cells | PNAS
Alterations of Phospholamban Function Can Exhibit Cardiotoxic Effects Independent of Excessive Sarcoplasmic Reticulum Ca2+...Alterations of Phospholamban Function Can Exhibit Cardiotoxic Effects Independent of Excessive Sarcoplasmic Reticulum Ca2+...
Increased Expression of Isoform 1 of the Sarcoplasmic Reticulum Ca2+-Release Channel in Failing Human Heart | CirculationIncreased Expression of Isoform 1 of the Sarcoplasmic Reticulum Ca2+-Release Channel in Failing Human Heart | Circulation
Direct in vivo monitoring of sarcoplasmic reticulum Ca2+ and cytosolic cAMP dynamics in mouse skeletal muscle | JCBDirect in vivo monitoring of sarcoplasmic reticulum Ca2+ and cytosolic cAMP dynamics in mouse skeletal muscle | JCB
Quantitative determination of Ca2+-dependent Mg2+-ATPase from sarcoplasmic reticulum in muscle biopsies | Biochemical JournalQuantitative determination of Ca2+-dependent Mg2+-ATPase from sarcoplasmic reticulum in muscle biopsies | Biochemical Journal
Targeted Overexpression of the Sarcoplasmic Reticulum Ca2+-ATPase Increases Cardiac Contractility in Transgenic Mouse Hearts |...Targeted Overexpression of the Sarcoplasmic Reticulum Ca2+-ATPase Increases Cardiac Contractility in Transgenic Mouse Hearts |...
Ionic selectivity, saturation, and block in a K+-selective channel from sarcoplasmic reticulum. | JGPIonic selectivity, saturation, and block in a K+-selective channel from sarcoplasmic reticulum. | JGP
Get PDF - The sarcoplasmic reticulum Ca(2+)-ATPase is depressed in stunned myocardium after ischemia-reperfusion, but remains...Get PDF - The sarcoplasmic reticulum Ca(2+)-ATPase is depressed in stunned myocardium after ischemia-reperfusion, but remains...
Junctional sarcoplasmic reticulum protein elisa and antibodyJunctional sarcoplasmic reticulum protein elisa and antibody
Nitric oxide-dependent activation of CaMKII increases diastolic sarcoplasmic reticulum calcium release in cardiac myocytes in...Nitric oxide-dependent activation of CaMKII increases diastolic sarcoplasmic reticulum calcium release in cardiac myocytes in...
Reactive disulfides trigger Ca<sup>2+</sup> release from sarcoplasmic reticulum via an oxidation...Reactive disulfides trigger Ca<sup>2+</sup> release from sarcoplasmic reticulum via an oxidation...
Sarcoplasmic reticulum Ca<sup>2+</sup> regulatory protein gene expression in human right atrium under hemodynamic...Sarcoplasmic reticulum Ca<sup>2+</sup> regulatory protein gene expression in human right atrium under hemodynamic...
Sarcoplasmic reticulum - WikipediaSarcoplasmic reticulum - Wikipedia
Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase 1 | SpringerLinkSarcoplasmic/Endoplasmic Reticulum Calcium ATPase 1 | SpringerLink
Sarcoplasmic reticulum - WikipediaSarcoplasmic reticulum - Wikipedia
Sarcoplasmic reticulum - definition of sarcoplasmic reticulum by The Free DictionarySarcoplasmic reticulum - definition of sarcoplasmic reticulum by The Free Dictionary
What Is the Function of Sarcoplasmic Reticulum? | Reference.comWhat Is the Function of Sarcoplasmic Reticulum? | Reference.com
The interaction of calcium and ryanodine with cardiac sarcoplasmic reticulum. - PubMed - NCBIThe interaction of calcium and ryanodine with cardiac sarcoplasmic reticulum. - PubMed - NCBI
The Development of the Sarcoplasmic Reticulum: 1st Edition (Hardback) - RoutledgeThe Development of the Sarcoplasmic Reticulum: 1st Edition (Hardback) - Routledge
S-ER - Sarcoplasmic and Endoplasmic Reticulum | AcronymFinderS-ER - Sarcoplasmic and Endoplasmic Reticulum | AcronymFinder
Sarcoplasmic ReticulumSarcoplasmic Reticulum
RCSB PDB - Protein Feature View - Sarcoplasmic/endoplasmic reticulum calcium ATPase 1 - O14983 (AT2A1 HUMAN)RCSB PDB - Protein Feature View - Sarcoplasmic/endoplasmic reticulum calcium ATPase 1 - O14983 (AT2A1 HUMAN)
Sarcoplasmic Reticulum, TEM - Stock Image C003/5275 - Science Photo...'Sarcoplasmic Reticulum, TEM' - Stock Image C003/5275 - Science Photo...
Human tlr3 to Human Sarcoplasmic Reticulum from Cell Signaling TechnologyHuman tlr3 to Human Sarcoplasmic Reticulum from Cell Signaling Technology
Sarcoplasmic reticulum - Biology-Online DictionarySarcoplasmic reticulum - Biology-Online Dictionary
Striations of the Sarcoplasmic ReticulumStriations of the Sarcoplasmic Reticulum
Molecular Structure of Canine Cardiac Phospholamban, the Regulatory Protein of Ca Pump ATPase of Sarcoplasmic Reticulum |...Molecular Structure of Canine Cardiac Phospholamban, the Regulatory Protein of Ca Pump ATPase of Sarcoplasmic Reticulum |...
Figure 4 | Alteration of Sarcoplasmic Reticulum Release in Skeletal Muscle from Calpain 3-Deficient MiceFigure 4 | Alteration of Sarcoplasmic Reticulum Release in Skeletal Muscle from Calpain 3-Deficient Mice
Phospholamban phosphorylation increases the passive calcium leak from cardiac sarcoplasmic reticulum. | Sigma-AldrichPhospholamban phosphorylation increases the passive calcium leak from cardiac sarcoplasmic reticulum. | Sigma-Aldrich
Decreased Sarcoplasmic Reticulum Activity and Contractility in Diabetic db/db Mouse Heart | DiabetesDecreased Sarcoplasmic Reticulum Activity and Contractility in Diabetic db/db Mouse Heart | Diabetes
ROLE OF THE SARCOPLASMIC RETICULUM IN GLYCOGEN METABOLISM | JCBROLE OF THE SARCOPLASMIC RETICULUM IN GLYCOGEN METABOLISM | JCB
Overexpression of the Sarcoplasmic Reticulum Ca2+-ATPase Improves Myocardial Contractility in Diabetic Cardiomyopathy | DiabetesOverexpression of the Sarcoplasmic Reticulum Ca2+-ATPase Improves Myocardial Contractility in Diabetic Cardiomyopathy | Diabetes
Palmitoyl-carnitine increases RyR2 oxidation and sarcoplasmic reticulum Ca2+ leak in cardiomyocytes: Role of adenine nucleotide...Palmitoyl-carnitine increases RyR2 oxidation and sarcoplasmic reticulum Ca2+ leak in cardiomyocytes: Role of adenine nucleotide...
ATP2A3 (ATPase sarcoplasmic/endoplasmic reticulum Ca2+ transporting 3)ATP2A3 (ATPase sarcoplasmic/endoplasmic reticulum Ca2+ transporting 3)
Role of the Sarcoplasmic Reticulum in Smooth MuscleRole of the Sarcoplasmic Reticulum in Smooth Muscle
Sodium current-induced release of calcium from cardiac sarcoplasmic reticulum | ScienceSodium current-induced release of calcium from cardiac sarcoplasmic reticulum | Science
Spatially and Functionally Distinct Ca2+ Stores in Sarcoplasmic and Endoplasmic Reticulum | ScienceSpatially and Functionally Distinct Ca2+ Stores in Sarcoplasmic and Endoplasmic Reticulum | Science
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AnatomyOrganismsDiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPhenomena and ProcessesDisciplines and OccupationsTechnology, Industry, AgricultureInformation ScienceHealth Care
Sarcoplasmic ReticulumCalcium-Transporting ATPasesSarcoplasmic Reticulum Calcium-Transporting ATPasesCalciumEndoplasmic ReticulumRyanodine Receptor Calcium Release ChannelRabbitsCaffeineCalsequestrinRyanodineMusclesMyocardiumCalcium-Binding ProteinsCa(2+) Mg(2+)-ATPaseMyocardial ContractionCalcium SignalingCalcium ChannelsAdenosine TriphosphateRuthenium RedMuscle ProteinsKineticsMyocytes, CardiacMuscle, SkeletalSodium-Calcium ExchangerMagnesiumThapsigarginAdenosine TriphosphatasesExcitation Contraction CouplingEgtazic AcidMuscle ContractionSarcolemmaCalcium Channels, L-TypeMicrosomesTetracaineHeart VentriclesProcaineMuscle Fibers, SkeletalMyofibrilsDantroleneOxalatesBiological Transport, ActiveDogsHeartIntracellular MembranesMalignant HyperthermiaMicroscopy, ElectronMembrane PotentialsEndoplasmic Reticulum StressPhosphorylationVanadiumFluorescent DyesMurexideBiological TransportHydrogen-Ion ConcentrationMuscle Fibers, Fast-TwitchCalcium RadioisotopesXanthenesIndolesBinding SitesEndoplasmic Reticulum, RoughNaphthalenesulfonatesVanadatesMembranesPapillary MusclesLasalocidPotassiumAdenosine DiphosphateFluorescein-5-isothiocyanatePhosphatesAction PotentialsMembrane ProteinsHalothaneTime FactorsIon TransportProtein BindingIsoproterenolSpectrometry, FluorescenceAequorinCytosolRana pipiensAmino Acid SequenceCalcium Channel BlockersVentricular FunctionMolecular Sequence DataStrontiumElectric StimulationProtein ConformationCells, CulturedInositol 1,4,5-Trisphosphate ReceptorsGuinea PigsMicroscopy, ConfocalFreeze FracturingTacrolimus Binding ProteinsLanthanumSaponinsEndoplasmic Reticulum, SmoothCalcium-Calmodulin-Dependent Protein Kinase Type 2TerpenesMuscle CellsLipid BilayersHydrolysisPotassium ChloridePatch-Clamp TechniquesAniline CompoundsCalreticulinGolgi ApparatusCell MembraneModels, BiologicalCalcium Channel AgonistsSodiumCell FractionationRats, WistarFura-2Tacrolimus Binding Protein 1AIon Channel GatingElectric ConductivityCresolsEnzyme InhibitorsOsmolar ConcentrationBuffersRanidaeCardiomegalyCalmodulinAdrenergic beta-AgonistsElectrophysiologyAnuraRats, Sprague-DawleyAdenylyl ImidodiphosphateIon ChannelsMitochondria, MuscleCytoplasmArrhythmias, CardiacHeart FailurePhosphodiesterase InhibitorsCalcium ChlorideTrypsinAlkaloidsProteolipidsHeart AtriaThymolFluorescamineSilver NitrateMuscle, SmoothDetergentsDose-Response Relationship, DrugBufo marinusFerretsThiocyanatesThiazepinesSulfhydryl CompoundsSodium-Potassium-Exchanging ATPaseMetals, Rare EarthMathematicsReceptors, CholinergicMolecular WeightMuscle Fibers, Slow-TwitchTetraphenylborateOrganophosphatesSwineMuscle FatigueDithiothreitolHomeostasisTemperatureModels, CardiovascularCalcimycinOxalic AcidElectrophoresis, Polyacrylamide GelNifedipineChelating AgentsMaleimidesRana temporariaCarrier ProteinsInositol 1,4,5-TrisphosphateMuscle Relaxants, CentralPermeabilityPhospholipidsTrifluoperazineCardiotonic AgentsCell LineSubcellular FractionsMuscle, Smooth, VascularReticulumMitochondria, HeartMutationMagnesium ChlorideCyclic AMP-Dependent Protein KinasesTerbiumCell Membrane PermeabilityBlotting, WesternRana catesbeianaReceptors, Adrenergic, betaPeptide FragmentsProtein TransportBoron CompoundsFluoresceinsIntracellular FluidSarcomeresEthylmaleimideEtiocholanoloneUnfolded Protein ResponseHistological Techniques
ATPaseSkeletalVesiclesMembraneDiastolic sarcoplasmic reticulumJunctional sarcoplasmic reticulumMembranesProteinProteinsMuscleRabbitMartonosiRegulationUptakeSmooth EndoplasmStriated muscle fibersLeakLumenMitochondriaRole of the sarcoplasmic reticulumForm of endoplasmic reticulum foundDevelopment of the sarcoplasmic reticulumFunction of Sarcoplasmic ReticulumChannel from sarcoplasmic reticulumCisternaeJunctionalPhospholambanSarcolemmaFound in the endoplasmic reticulumCytosolicTransverse tubulesIntracellular membrane systemVentricularExpressionSERCA2Adenosine triphosphataseRough endoplasmCytoplasmRabbit skeletal
ATPase3
Skeletal5
Vesicles2
Membrane2
  • Sarcalumenin is a 160 kDa acidic calcium binding glycoprotein found to reside at the inner membrane of the sarcoplasmic reticulum in a calcium dependent manner.The gene encoding sarcalumenin also encodes an alternate splice variant, a 53 kDa glycoprotein which co-localizes with sarcalumenin. (novusbio.com)
  • The sarcoplasmic reticulum (SR) is a membrane-bound structure found within the cardiac muscle cells. (cure-plan.online)
Diastolic sarcoplasmic reticulum1
Junctional sarcoplasmic reticulum1
Membranes1
  • These two proteins are found in the longitudinal sarcoplasmic reticulum and the nonjunctional membranes of the terminal cisternae. (novusbio.com)
Protein2
  • Focusing on the development of the sarcoplasmic reticulum, Martonosi demonstrates the regulatory functions that control the production of its molecular components and investigates the interaction of these lipid and protein molecules with the myogenic, neurogenic and hormonal stimuli present in developing muscle cells. (ebooks.com)
  • Regulation of Sarcoplasmic Reticulum Protein Composition and Turnover by Proteolysis 6. (ebooks.com)
Proteins1
Muscle2
Rabbit1
  • Rabbit sarcoplasmic reticulum does contain trace amounts of gangliosides, and the main species is GM 3 . (elsevier.com)
Martonosi1
  • Anthony Martonosi presents general information about the development and function of the sarcoplasmic reticulum within a framework of contemporary research on the molecular biology of biosynthetic and signaling processes. (ebooks.com)
Regulation1
  • Regulation of the Phospholipid Composition of Sarcoplasmic Reticulum During Development 7. (ebooks.com)
Uptake4
  • reported that an increased mitochondrial calcium content (induced by LPS) was associated with reduced calcium uptake by and increased calcium leakage from the sarcoplasmic reticulum and it was also associated with decreased [DELTA]p, mitochondrial uncoupling, altered state 3 respiration, and impaired RCR. (thefreedictionary.com)
  • The data obtained support the hypothesis that ryanodine binding to the low-affinity site (Km about 17 microM) is responsible for closure of the calcium release channel and the subsequent increase in the calcium uptake rate of the sarcoplasmic reticulum. (nih.gov)
  • PLN −/− +TgPLN R9C hearts demonstrated accelerated sarcoplasmic reticulum Ca 2+ uptake rates and improved hemodynamics compared with PLN +/+ +TgPLN R9C mice but still responded poorly to β-adrenergic stimulation because PLN R9C impairs protein kinase A-mediated phosphorylation of both wild-type and mutant PLN. (ahajournals.org)
  • Several groups suggest that a major cause of force loss during fatigue is reductions in the rates of sarcoplasmic reticulum (SR) calcium (Ca2+) release and uptake. (vt.edu)
Smooth Endoplasm8
Striated muscle fibers1
Leak6
Lumen1
  • The sarcoplasmic reticulum (SR) of skeletal muscle cells is a complex network of tubules and cisternae that share a common lumen delimited by a single continuous membrane. (pnas.org)
Mitochondria4
Role of the sarcoplasmic reticulum4
Form of endoplasmic reticulum found1
Development of the sarcoplasmic reticulum1
  • Focusing on the development of the sarcoplasmic reticulum, Martonosi demonstrates the regulatory functions that control the production of its molecular components and investigates the interaction of these lipid and protein molecules with the myogenic, neurogenic and hormonal stimuli present in developing muscle cells. (routledge.com)
Function of Sarcoplasmic Reticulum1
Channel from sarcoplasmic reticulum1
  • Ionic selectivity, saturation, and block in a K+-selective channel from sarcoplasmic reticulum. (rupress.org)
Cisternae5
  • The endoplasmic reticulum ( ER ) is a type of organelle in the cells of eukaryotic organisms that forms an interconnected network of flattened, membrane-enclosed sacs or tube-like structures known as cisternae . (wn.com)
  • In addition, the transverse tubules were observed to be continuous across the width of the fiber, a set of flat intermediate cisternae was seen to connect the terminal cisternae to the longitudinal tubules in the A band, and the continuous reticulum collar at the center of the A band was found to be perforated by circular and elongated pores (the fenestrated collar). (rupress.org)
  • together these three components form the triads that exist within the network of the sarcoplasmic reticulum, in which each T tubule has two terminal cisternae on each side of it. (wikipedia.org)
  • The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules , vesicles and cisternae . (wikidoc.org)
  • The general structure of the endoplasmic reticulum is an extensive membrane network of cisternae (sac-like structures) held together by the cytoskeleton . (wikidoc.org)
Junctional1
Phospholamban1
  • Phospholamban (PLN) is a 52 amino acid integral membrane protein of the sarcoplasmic reticulum (SR) that exists in both monomeric and pentameric forms. (sigmaaldrich.com)
Sarcolemma1
Found in the endoplasmic reticulum1
Cytosolic1
Transverse tubules1
Intracellular membrane system1
Ventricular1
Expression1
SERCA21
Adenosine triphosphatase2
Rough endoplasm4
Cytoplasm1
Rabbit skeletal1
Membrane Dynamics and Calcium Signaling | SpringerLink
Membrane Dynamics and Calcium Signaling | SpringerLink (link.springer.com)
Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase 1 | SpringerLink
Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase 1 | SpringerLink (link.springer.com)
The Development of the Sarcoplasmic Reticulum: 1st Edition (Hardback) - Routledge
The Development of the Sarcoplasmic Reticulum: 1st Edition (Hardback) - Routledge (routledge.com)
Skeletal Muscle | MindMeister Mind Map
Skeletal Muscle | MindMeister Mind Map (mindmeister.com)
Biomechanics Muscles | Myocyte | Muscle
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Myocyte - Wikipedia
Myocyte - Wikipedia (en.wikipedia.org)
Mitochondrial-Shaping Proteins in Cardiac Health and Disease - the Long and the Short of It! | SpringerLink
Mitochondrial-Shaping Proteins in Cardiac Health and Disease - the Long and the Short of It! | SpringerLink (link.springer.com)
Cardiac Electrical Alternans and Ventricular Fibrillation During Hypothermia in Non-Hibernating Versus Hibernating Animals:...
Cardiac Electrical Alternans and Ventricular Fibrillation During Hypothermia in Non-Hibernating Versus Hibernating Animals:... (link.springer.com)
Write balanced equations for the reaction of lithium, | bartleby
Write balanced equations for the reaction of lithium, | bartleby (bartleby.com)
The quantal nature of Ca2+ sparks and in situ operation of the ryanodine receptor array in cardiac cells | PNAS
The quantal nature of Ca2+ sparks and in situ operation of the ryanodine receptor array in cardiac cells | PNAS (pnas.org)
Darier disease: MedlinePlus Genetics
Darier disease: MedlinePlus Genetics (medlineplus.gov)
Antiproliferative and Cytotoxic Activities | SpringerLink
Antiproliferative and Cytotoxic Activities | SpringerLink (link.springer.com)
Enhanced expression of transient receptor potential channels in idiopathic pulmonary arterial hypertension | PNAS
Enhanced expression of transient receptor potential channels in idiopathic pulmonary arterial hypertension | PNAS (pnas.org)
SWISS-MODEL Template Library | 5a3q.1
SWISS-MODEL Template Library | 5a3q.1 (swissmodel.expasy.org)
BKCa channel regulates calcium oscillations induced by alpha-2-macroglobulin in human myometrial smooth muscle cells | PNAS
BKCa channel regulates calcium oscillations induced by alpha-2-macroglobulin in human myometrial smooth muscle cells | PNAS (pnas.org)
Alphabetical Browse | Britannica
Alphabetical Browse | Britannica (britannica.com)
Molecular Structure of Canine Cardiac Phospholamban, the Regulatory Protein of Ca Pump ATPase of Sarcoplasmic Reticulum |...
Molecular Structure of Canine Cardiac Phospholamban, the Regulatory Protein of Ca Pump ATPase of Sarcoplasmic Reticulum |... (link.springer.com)
Daniel Bradley : Trinity Research - Trinity College Dublin
Daniel Bradley : Trinity Research - Trinity College Dublin (tcd.ie)
Hibernating and Stunned Myocardium Imaging: Practice Essentials, Definition, Mechanism of Disease
Hibernating and Stunned Myocardium Imaging: Practice Essentials, Definition, Mechanism of Disease (emedicine.medscape.com)
ATP-Driven Ca2+ Pump Activity of Macrophage and Neutrophil Plasma Membrane | SpringerLink
ATP-Driven Ca2+ Pump Activity of Macrophage and Neutrophil Plasma Membrane | SpringerLink (link.springer.com)
ROLE OF THE SARCOPLASMIC RETICULUM IN GLYCOGEN METABOLISM | JCB
ROLE OF THE SARCOPLASMIC RETICULUM IN GLYCOGEN METABOLISM | JCB (jcb.rupress.org)
Search | Britannica
Search | Britannica (britannica.com)
Table of Contents - January 19, 1999, 96 (2) | PNAS
Table of Contents - January 19, 1999, 96 (2) | PNAS (pnas.org)
Category:Muscles - Wikimedia Commons
Category:Muscles - Wikimedia Commons (commons.wikimedia.org)
The Hepatic Microsomal Ca2+ Sequestering System | SpringerLink
The Hepatic Microsomal Ca2+ Sequestering System | SpringerLink (link.springer.com)
Dysregulation of Ionic Homeostasis: Relevance for Cardiac Arrhythmias | SpringerLink
Dysregulation of Ionic Homeostasis: Relevance for Cardiac Arrhythmias | SpringerLink (link.springer.com)
Sodium current-induced release of calcium from cardiac sarcoplasmic reticulum | Science
Sodium current-induced release of calcium from cardiac sarcoplasmic reticulum | Science (science.sciencemag.org)
Frontiers | Molecular Determinants of Cephalopod Muscles and Their Implication in Muscle Regeneration | Cell and Developmental...
Frontiers | Molecular Determinants of Cephalopod Muscles and Their Implication in Muscle Regeneration | Cell and Developmental... (frontiersin.org)