Mitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)Mitochondria, Liver: Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)Muscles: Contractile tissue that produces movement in animals.Mitochondria, Heart: The mitochondria of the myocardium.Mitochondria, Muscle: Mitochondria of skeletal and smooth muscle. It does not include myocardial mitochondria for which MITOCHONDRIA, HEART is available.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.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.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)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.Muscle, Smooth, Vascular: The nonstriated involuntary muscle tissue of blood vessels.Muscle Development: Developmental events leading to the formation of adult muscular system, which includes differentiation of the various types of muscle cell precursors, migration of myoblasts, activation of myogenesis and development of muscle anchorage.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.Mitochondrial Proteins: Proteins encoded by the mitochondrial genome or proteins encoded by the nuclear genome that are imported to and resident in the MITOCHONDRIA.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.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.Muscle Denervation: The resection or removal of the innervation of a muscle or muscle tissue.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.Oxidative Phosphorylation: Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.Mitochondrial Swelling: An increase in MITOCHONDRIAL VOLUME due to an influx of fluid; it occurs in hypotonic solutions due to osmotic pressure and in isotonic solutions as a result of altered permeability of the membranes of respiring mitochondria.Oxygen Consumption: The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)Myocytes, Smooth Muscle: Non-striated, elongated, spindle-shaped cells found lining the digestive tract, uterus, and blood vessels. They are derived from specialized myoblasts (MYOBLASTS, SMOOTH MUSCLE).Mitochondrial Membranes: The two lipoprotein layers in the MITOCHONDRION. The outer membrane encloses the entire mitochondrion and contains channels with TRANSPORT PROTEINS to move molecules and ions in and out of the organelle. The inner membrane folds into cristae and contains many ENZYMES important to cell METABOLISM and energy production (MITOCHONDRIAL ATP SYNTHASE).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.Oculomotor Muscles: The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.Neck Muscles: The neck muscles consist of the platysma, splenius cervicis, sternocleidomastoid(eus), longus colli, the anterior, medius, and posterior scalenes, digastric(us), stylohyoid(eus), mylohyoid(eus), geniohyoid(eus), sternohyoid(eus), omohyoid(eus), sternothyroid(eus), and thyrohyoid(eus).Muscle, Striated: One of two types of muscle in the body, characterized by the array of bands observed under microscope. Striated muscles can be divided into two subtypes: the CARDIAC MUSCLE and the SKELETAL MUSCLE.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.Cell Respiration: The metabolic process of all living cells (animal and plant) in which oxygen is used to provide a source of energy for the cell.Muscle Spindles: Skeletal muscle structures that function as the MECHANORECEPTORS responsible for the stretch or myotactic reflex (REFLEX, STRETCH). They are composed of a bundle of encapsulated SKELETAL MUSCLE FIBERS, i.e., the intrafusal fibers (nuclear bag 1 fibers, nuclear bag 2 fibers, and nuclear chain fibers) innervated by SENSORY NEURONS.Muscle Relaxation: That phase of a muscle twitch during which a muscle returns to a resting position.DNA, Mitochondrial: Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.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.Papillary Muscles: Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.Respiratory Muscles: These include the muscles of the DIAPHRAGM and the INTERCOSTAL MUSCLES.Muscle Weakness: A vague complaint of debility, fatigue, or exhaustion attributable to weakness of various muscles. The weakness can be characterized as subacute or chronic, often progressive, and is a manifestation of many muscle and neuromuscular diseases. (From Wyngaarden et al., Cecil Textbook of Medicine, 19th ed, p2251)Electron Transport Complex IV: A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.Uncoupling Agents: Chemical agents that uncouple oxidation from phosphorylation in the metabolic cycle so that ATP synthesis does not occur. Included here are those IONOPHORES that disrupt electron transfer by short-circuiting the proton gradient across mitochondrial membranes.Membrane Potential, Mitochondrial: The voltage difference, normally maintained at approximately -180mV, across the INNER MITOCHONDRIAL MEMBRANE, by a net movement of positive charge across the membrane. It is a major component of the PROTON MOTIVE FORCE in MITOCHONDRIA used to drive the synthesis of ATP.Cytochromes c: Cytochromes of the c type that are found in eukaryotic MITOCHONDRIA. They serve as redox intermediates that accept electrons from MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III and transfer them to MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX IV.Mitochondrial Membrane Transport Proteins: Proteins involved in the transport of specific substances across the membranes of the MITOCHONDRIA.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.Abdominal Muscles: Muscles forming the ABDOMINAL WALL including RECTUS ABDOMINIS, external and internal oblique muscles, transversus abdominis, and quadratus abdominis. (from Stedman, 25th ed)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.Quadriceps Muscle: The quadriceps femoris. A collective name of the four-headed skeletal muscle of the thigh, comprised of the rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis.Kinetics: The rate dynamics in chemical or physical systems.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.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Reactive Oxygen Species: Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.Oligomycins: A closely related group of toxic substances elaborated by various strains of Streptomyces. They are 26-membered macrolides with lactone moieties and double bonds and inhibit various ATPases, causing uncoupling of phosphorylation from mitochondrial respiration. Used as tools in cytochemistry. Some specific oligomycins are RUTAMYCIN, peliomycin, and botrycidin (formerly venturicidin X).Masseter Muscle: A masticatory muscle whose action is closing the jaws.MalatesMolecular 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.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.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).Facial Muscles: Muscles of facial expression or mimetic muscles that include the numerous muscles supplied by the facial nerve that are attached to and move the skin of the face. (From Stedman, 25th ed)Masticatory Muscles: Muscles arising in the zygomatic arch that close the jaw. Their nerve supply is masseteric from the mandibular division of the trigeminal nerve. (From Stedman, 25th ed)Muscular Atrophy: Derangement in size and number of muscle fibers occurring with aging, reduction in blood supply, or following immobilization, prolonged weightlessness, malnutrition, and particularly in denervation.Intercostal Muscles: Respiratory muscles that arise from the lower border of one rib and insert into the upper border of the adjoining rib, and contract during inspiration or respiration. (From Stedman, 25th ed)Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.Cytochrome c Group: A group of cytochromes with covalent thioether linkages between either or both of the vinyl side chains of protoheme and the protein. (Enzyme Nomenclature, 1992, p539)Rotenone: A botanical insecticide that is an inhibitor of mitochondrial electron transport.Atractyloside: A glycoside of a kaurene type diterpene that is found in some plants including Atractylis gummifera (ATRACTYLIS); COFFEE; XANTHIUM, and CALLILEPIS. Toxicity is due to inhibition of ADENINE NUCLEOTIDE TRANSLOCASE.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.Isometric Contraction: Muscular contractions characterized by increase in tension without change in length.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 .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.Antimycin A: An antibiotic substance produced by Streptomyces species. It inhibits mitochondrial respiration and may deplete cellular levels of ATP. Antimycin A1 has been used as a fungicide, insecticide, and miticide. (From Merck Index, 12th ed)Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone: A proton ionophore that is commonly used as an uncoupling agent in biochemical studies.Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.Satellite Cells, Skeletal Muscle: Elongated, spindle-shaped, quiescent myoblasts lying in close contact with adult skeletal muscle. They are thought to play a role in muscle repair and regeneration.Energy Metabolism: The chemical reactions involved in the production and utilization of various forms of energy in cells.Pectoralis Muscles: The pectoralis major and pectoralis minor muscles that make up the upper and fore part of the chest in front of the AXILLA.Muscular Diseases: Acquired, familial, and congenital disorders of SKELETAL MUSCLE and SMOOTH MUSCLE.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.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)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.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.Mitochondrial ADP, ATP Translocases: A class of nucleotide translocases found abundantly in mitochondria that function as integral components of the inner mitochondrial membrane. They facilitate the exchange of ADP and ATP between the cytosol and the mitochondria, thereby linking the subcellular compartments of ATP production to those of ATP utilization.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.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.Submitochondrial Particles: The various filaments, granules, tubules or other inclusions within mitochondria.Carbonyl Cyanide m-Chlorophenyl Hydrazone: A proton ionophore. It is commonly used as an uncoupling agent and inhibitor of photosynthesis because of its effects on mitochondrial and chloroplast membranes.Succinates: Derivatives of SUCCINIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a 1,4-carboxy terminated aliphatic structure.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Adenosine Diphosphate: Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.Oxidative Stress: A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.NAD: A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)Citrate (si)-Synthase: Enzyme that catalyzes the first step of the tricarboxylic acid cycle (CITRIC ACID CYCLE). It catalyzes the reaction of oxaloacetate and acetyl CoA to form citrate and coenzyme A. This enzyme was formerly listed as EC 4.1.3.7.Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Psoas Muscles: A powerful flexor of the thigh at the hip joint (psoas major) and a weak flexor of the trunk and lumbar spinal column (psoas minor). Psoas is derived from the Greek "psoa", the plural meaning "muscles of the loin". It is a common site of infection manifesting as abscess (PSOAS ABSCESS). The psoas muscles and their fibers are also used frequently in experiments in muscle physiology.Permeability: Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.bcl-2-Associated X Protein: A member of the Bcl-2 protein family and homologous partner of C-BCL-2 PROTO-ONCOGENE PROTEIN. It regulates the release of CYTOCHROME C and APOPTOSIS INDUCING FACTOR from the MITOCHONDRIA. Several isoforms of BCL2-associated X protein occur due to ALTERNATIVE SPLICING of the mRNA for this protein.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Electron Transport Complex I: A flavoprotein and iron sulfur-containing oxidoreductase complex that catalyzes the conversion of UBIQUINONE to ubiquinol. In MITOCHONDRIA the complex also couples its reaction to the transport of PROTONS across the internal mitochondrial membrane. The NADH DEHYDROGENASE component of the complex can be isolated and is listed as EC 1.6.99.3.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Hindlimb: Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)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)Electric Stimulation: Use of electric potential or currents to elicit biological responses.Temporal Muscle: A masticatory muscle whose action is closing the jaws; its posterior portion retracts the mandible.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.Succinate Dehydrogenase: A flavoprotein containing oxidoreductase that catalyzes the dehydrogenation of SUCCINATE to fumarate. In most eukaryotic organisms this enzyme is a component of mitochondrial electron transport complex II.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Succinic Acid: A water-soluble, colorless crystal with an acid taste that is used as a chemical intermediate, in medicine, the manufacture of lacquers, and to make perfume esters. It is also used in foods as a sequestrant, buffer, and a neutralizing agent. (Hawley's Condensed Chemical Dictionary, 12th ed, p1099; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1851)Cell Fractionation: Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Caspases: A family of intracellular CYSTEINE ENDOPEPTIDASES that play a role in regulating INFLAMMATION and APOPTOSIS. They specifically cleave peptides at a CYSTEINE amino acid that follows an ASPARTIC ACID residue. Caspases are activated by proteolytic cleavage of a precursor form to yield large and small subunits that form the enzyme. Since the cleavage site within precursors matches the specificity of caspases, sequential activation of precursors by activated caspases can occur.Myosin Heavy Chains: The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. The heavy chains possess actin-binding and ATPase activity.Proto-Oncogene Proteins c-bcl-2: Membrane proteins encoded by the BCL-2 GENES and serving as potent inhibitors of cell death by APOPTOSIS. The proteins are found on mitochondrial, microsomal, and NUCLEAR MEMBRANE sites within many cell types. Overexpression of bcl-2 proteins, due to a translocation of the gene, is associated with follicular lymphoma.Mitochondrial Proton-Translocating ATPases: Proton-translocating ATPases responsible for ADENOSINE TRIPHOSPHATE synthesis in the MITOCHONDRIA. They derive energy from the respiratory chain-driven reactions that develop high concentrations of protons within the intermembranous space of the mitochondria.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.Mersalyl: A toxic thiol mercury salt formerly used as a diuretic. It inhibits various biochemical functions, especially in mitochondria, and is used to study those functions.Mitochondrial Diseases: Diseases caused by abnormal function of the MITOCHONDRIA. They may be caused by mutations, acquired or inherited, in mitochondrial DNA or in nuclear genes that code for mitochondrial components. They may also be the result of acquired mitochondria dysfunction due to adverse effects of drugs, infections, or other environmental causes.Motor Neurons: Neurons which activate MUSCLE CELLS.Diaphragm: The musculofibrous partition that separates the THORACIC CAVITY from the ABDOMINAL CAVITY. Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION.GlycogenIon 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.Aging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Carnitine: A constituent of STRIATED MUSCLE and LIVER. It is an amino acid derivative and an essential cofactor for fatty acid metabolism.Pharyngeal Muscles: The muscles of the PHARYNX are voluntary muscles arranged in two layers. The external circular layer consists of three constrictors (superior, middle, and inferior). The internal longitudinal layer consists of the palatopharyngeus, the salpingopharyngeus, and the stylopharyngeus. During swallowing, the outer layer constricts the pharyngeal wall and the inner layer elevates pharynx and LARYNX.Sarcolemma: The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Voltage-Dependent Anion Channels: A family of voltage-gated eukaryotic porins that form aqueous channels. They play an essential role in mitochondrial CELL MEMBRANE PERMEABILITY, are often regulated by BCL-2 PROTO-ONCOGENE PROTEINS, and have been implicated in APOPTOSIS.Mice, Inbred C57BLUbiquinone: A lipid-soluble benzoquinone which is involved in ELECTRON TRANSPORT in mitochondrial preparations. The compound occurs in the majority of aerobic organisms, from bacteria to higher plants and animals.Electron Transport Complex III: A multisubunit enzyme complex that contains CYTOCHROME B GROUP; CYTOCHROME C1; and iron-sulfur centers. It catalyzes the oxidation of ubiquinol to UBIQUINONE, and transfers the electrons to CYTOCHROME C. In MITOCHONDRIA the redox reaction is coupled to the transport of PROTONS across the inner mitochondrial membrane.Hydrogen Peroxide: A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.Cardiolipins: Acidic phospholipids composed of two molecules of phosphatidic acid covalently linked to a molecule of glycerol. They occur primarily in mitochondrial inner membranes and in bacterial plasma membranes. They are the main antigenic components of the Wassermann-type antigen that is used in nontreponemal SYPHILIS SERODIAGNOSIS.Actins: Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.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.Neuromuscular Junction: The synapse between a neuron and a muscle.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)Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Myoblasts: Embryonic (precursor) cells of the myogenic lineage that develop from the MESODERM. They undergo proliferation, migrate to their various sites, and then differentiate into the appropriate form of myocytes (MYOCYTES, SKELETAL; MYOCYTES, CARDIAC; MYOCYTES, SMOOTH MUSCLE).Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.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.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)NADH Dehydrogenase: A flavoprotein and iron sulfur-containing oxidoreductase that catalyzes the oxidation of NADH to NAD. In eukaryotes the enzyme can be found as a component of mitochondrial electron transport complex I. Under experimental conditions the enzyme can use CYTOCHROME C GROUP as the reducing cofactor. The enzyme was formerly listed as EC 1.6.2.1.Phosphates: Inorganic salts of phosphoric acid.Glucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Enzyme Activation: Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.Bongkrekic Acid: An antibiotic produced by Pseudomonas cocovenenans. It is an inhibitor of MITOCHONDRIAL ADP, ATP TRANSLOCASES. Specifically, it blocks adenine nucleotide efflux from mitochondria by enhancing membrane binding.Muscular Dystrophy, AnimalMicroscopy, Electron, Transmission: Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.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)Creatine Kinase: A transferase that catalyzes formation of PHOSPHOCREATINE from ATP + CREATINE. The reaction stores ATP energy as phosphocreatine. Three cytoplasmic ISOENZYMES have been identified in human tissues: the MM type from SKELETAL MUSCLE, the MB type from myocardial tissue and the BB type from nervous tissue as well as a mitochondrial isoenzyme. Macro-creatine kinase refers to creatine kinase complexed with other serum proteins.MalonatesKetoglutaric Acids: A family of compounds containing an oxo group with the general structure of 1,5-pentanedioic acid. (From Lehninger, Principles of Biochemistry, 1982, p442)Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Mitochondrial Dynamics: The continuous remodeling of MITOCHONDRIA shape by fission and fusion in response to physiological conditions.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Membranes: Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.Mitochondrial Degradation: Proteolytic breakdown of the MITOCHONDRIA.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.Proton-Translocating ATPases: Multisubunit enzymes that reversibly synthesize ADENOSINE TRIPHOSPHATE. They are coupled to the transport of protons across a membrane.Pyruvic Acid: An intermediate compound in the metabolism of carbohydrates, proteins, and fats. In thiamine deficiency, its oxidation is retarded and it accumulates in the tissues, especially in nervous structures. (From Stedman, 26th ed)Muscle Cramp: A sustained and usually painful contraction of muscle fibers. This may occur as an isolated phenomenon or as a manifestation of an underlying disease process (e.g., UREMIA; HYPOTHYROIDISM; MOTOR NEURON DISEASE; etc.). (From Adams et al., Principles of Neurology, 6th ed, p1398)Polarography: An electrochemical technique for measuring the current that flows in solution as a function of an applied voltage. The observed polarographic wave, resulting from the electrochemical response, depends on the way voltage is applied (linear sweep or differential pulse) and the type of electrode used. Usually a mercury drop electrode is used.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.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.Enzyme 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.Carnitine O-Palmitoyltransferase: An enzyme that catalyzes reversibly the conversion of palmitoyl-CoA to palmitoylcarnitine in the inner mitochondrial membrane. EC 2.3.1.21.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.Insulin: A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).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.Hexokinase: An enzyme that catalyzes the conversion of ATP and a D-hexose to ADP and a D-hexose 6-phosphate. D-Glucose, D-mannose, D-fructose, sorbitol, and D-glucosamine can act as acceptors; ITP and dATP can act as donors. The liver isoenzyme has sometimes been called glucokinase. (From Enzyme Nomenclature, 1992) EC 2.7.1.1.BH3 Interacting Domain Death Agonist Protein: A member of the Bcl-2 protein family that reversibly binds MEMBRANES. It is a pro-apoptotic protein that is activated by caspase cleavage.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.Organelles: Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the MITOCHONDRIA; the GOLGI APPARATUS; ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.Physical Exertion: Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.PyruvatesSarcoplasmic 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.Sarcomeres: The repeating contractile units of the MYOFIBRIL, delimited by Z bands along its length.Glycolysis: A metabolic process that converts GLUCOSE into two molecules of PYRUVIC ACID through a series of enzymatic reactions. Energy generated by this process is conserved in two molecules of ATP. Glycolysis is the universal catabolic pathway for glucose, free glucose, or glucose derived from complex CARBOHYDRATES, such as GLYCOGEN and STARCH.Saccharomyces cerevisiae Proteins: Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.Regeneration: The physiological renewal, repair, or replacement of tissue.Voltage-Dependent Anion Channel 1: Voltage-dependent anion channel 1 is the major pore-forming protein of the mitochondrial outer membrane. It also functions as a ferricyanide reductase in the PLASMA MEMBRANE.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Neurospora crassa: A species of ascomycetous fungi of the family Sordariaceae, order SORDARIALES, much used in biochemical, genetic, and physiologic studies.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Mice, Inbred mdx: A strain of mice arising from a spontaneous MUTATION (mdx) in inbred C57BL mice. This mutation is X chromosome-linked and produces viable homozygous animals that lack the muscle protein DYSTROPHIN, have high serum levels of muscle ENZYMES, and possess histological lesions similar to human MUSCULAR DYSTROPHY. The histological features, linkage, and map position of mdx make these mice a worthy animal model of DUCHENNE MUSCULAR DYSTROPHY.Mitochondrial Size: The quantity of volume or surface area of MITOCHONDRIA.Apoptosis Inducing Factor: A flavoprotein that functions as a powerful antioxidant in the MITOCHONDRIA and promotes APOPTOSIS when released from the mitochondria. In mammalian cells AIF is released in response to pro-apoptotic protein members of the bcl-2 protein family. It translocates to the CELL NUCLEUS and binds DNA to stimulate CASPASE-independent CHROMATIN condensation.Histocytochemistry: Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.Palmitoyl Coenzyme A: A fatty acid coenzyme derivative which plays a key role in fatty acid oxidation and biosynthesis.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.Valinomycin: A cyclododecadepsipeptide ionophore antibiotic produced by Streptomyces fulvissimus and related to the enniatins. It is composed of 3 moles each of L-valine, D-alpha-hydroxyisovaleric acid, D-valine, and L-lactic acid linked alternately to form a 36-membered ring. (From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies.Autophagy: The segregation and degradation of damaged or unwanted cytoplasmic constituents by autophagic vacuoles (cytolysosomes) composed of LYSOSOMES containing cellular components in the process of digestion; it plays an important role in BIOLOGICAL METAMORPHOSIS of amphibians, in the removal of bone by osteoclasts, and in the degradation of normal cell components in nutritional deficiency states.Exercise: Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.Digitonin: A glycoside obtained from Digitalis purpurea; the aglycone is digitogenin which is bound to five sugars. Digitonin solubilizes lipids, especially in membranes and is used as a tool in cellular biochemistry, and reagent for precipitating cholesterol. It has no cardiac effects.

Expression of uncoupling protein-3 and mitochondrial activity in the transition from hypothyroid to hyperthyroid state in rat skeletal muscle. (1/1585)

We sought a correlation between rat skeletal muscle triiodothyronine (T3)-mediated regulation of uncoupling protein-3 (UCP3) expression and mitochondrial activity. UCP3 mRNA expression increased strongly during the hypothyroid-hyperthyroid transition. The rank order of mitochondrial State 3 and State 4 respiration rates was hypothyroid < euthyroid < hyperthyroid. The State 4 increase may have been due to the increased UCP3 expression, as the proton leak kinetic was stimulated in the hypothyroid-hyperthyroid transition and a good correlation exists between the State 4 and UCP3 mRNA level. As a significant proportion of an organism's resting oxygen consumption is dedicated to opposing the proton leak, skeletal muscle mitochondrial UCP3 may mediate part of T3's effect on energy metabolism.  (+info)

Reduced cytosolic acidification during exercise suggests defective glycolytic activity in skeletal muscle of patients with Becker muscular dystrophy. An in vivo 31P magnetic resonance spectroscopy study. (2/1585)

Becker muscular dystrophy is an X-linked disorder due to mutations in the dystrophin gene, resulting in reduced size and/or content of dystrophin. The functional role of this subsarcolemma protein and the biochemical mechanisms leading to muscle necrosis in Becker muscular dystrophy are still unknown. In particular, the role of a bioenergetic deficit is still controversial. In this study, we used 31p magnetic resonance spectroscopy (31p-MRS) to investigate skeletal muscle mitochondrial and glycolytic ATP production in vivo in 14 Becker muscular dystrophy patients. Skeletal muscle glycogenolytic ATP production, measured during the first minute of exercise, was similar in patients and controls. On the other hand, during later phases of exercise, skeletal muscle in Becker muscular dystrophy patients was less acidic than in controls, the cytosolic pH at the end of exercise being significantly higher in Becker muscular dystrophy patients. The rate of proton efflux from muscle fibres of Becker muscular dystrophy patients was similar to that of controls, pointing to a deficit in glycolytic lactate production as a cause of higher end-exercise cytosolic pH in patients. The maximum rate of mitochondrial ATP production was similar in muscle of Becker muscular dystrophy patients and controls. The results of this in vivo 31P-MRS study are consistent with reduced glucose availability in dystrophin-deficient muscles.  (+info)

Subcellular adaptation of the human diaphragm in chronic obstructive pulmonary disease. (3/1585)

Pulmonary hyperinflation impairs the function of the diaphragm in patients with chronic obstructive pulmonary disease (COPD). However, it has been recently demonstrated that the muscle can counterbalance this deleterious effect, remodelling its structure (i.e. changing the proportion of different types of fibres). The aim of this study was to investigate whether the functional impairment present in COPD patients can be associated with structural subcellular changes of the diaphragm. Twenty individuals (60+/-9 yrs, 11 COPD patients and 9 subjects with normal spirometry) undergoing thoracotomy were included. Nutritional status and respiratory function were evaluated prior to surgery. Then, small samples of the costal diaphragm were obtained and processed for electron microscopy analysis. COPD patients showed a mean forced expiratory volume in one second (FEV1) of 60+/-9% predicted, a higher concentration of mitochondria (n(mit)) in their diaphragm than controls (0.62+/-0.16 versus 0.46+/-0.16 mitochondrial transections (mt) x microm(-2), p<0.05). On the other hand, subjects with air trapping (residual volume (RV)/total lung capacity (TLC) >37%) disclosed not only a higher n(mit) (0.63+/-0.17 versus 0.43+/-0.07 mt x microm(-2), p<0.05) but shorter sarcomeres (L(sar)) than subjects without this functional abnormality (2.08+/-0.16 to 2.27+/-0.15 microm, p<0.05). Glycogen stores were similar in COPD and controls. The severity of airways obstruction (i.e. FEV1) was associated with n(mit) (r=-0.555, p=0.01), while the amount of air trapping (i.e. RV/TLC) was found to correlate with both n(mit) (r=0.631, p=0.005) and L(sar) (r=-0.526, p<0.05). Finally, maximal inspiratory pressure (PI,max) inversely correlated with n(mit) (r=-0.547, p=0.01). In conclusion, impairment in lung function occurring in patients with chronic obstructive pulmonary disease is associated with subcellular changes in their diaphragm, namely a shortening in the length of sarcomeres and an increase in the concentration of mitochondria. These changes form a part of muscle remodelling, probably contributing to a better functional muscle behaviour.  (+info)

Release of Ca2+ from the sarcoplasmic reticulum increases mitochondrial [Ca2+] in rat pulmonary artery smooth muscle cells. (4/1585)

1. The Ca2+-sensitive fluorescent indicator rhod-2 was used to measure mitochondrial [Ca2+] ([Ca2+]m) in single smooth muscle cells from the rat pulmonary artery, while simultaneously monitoring cytosolic [Ca2+] ([Ca2+]i) with fura-2. 2. Application of caffeine produced an increase in [Ca2+]i and also increased [Ca2+]m. The increase in [Ca2+]m occurred after the increase in [Ca2+]i, and remained elevated for a considerable time after [Ca2+]i had returned to resting values. 3. The protonophore carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP), which causes the mitochondrial membrane potential to collapse, markedly attenuated the increase in [Ca2+]m following caffeine application and also increased the half-time for recovery of [Ca2+]i to resting values. 4. Activation of purinoceptors with ATP also produced increases in both [Ca2+]i and [Ca2+]m in these smooth muscle cells. In some cells, oscillations in [Ca2+]i were observed during ATP application, which produced corresponding oscillations in [Ca2+]m and membrane currents. 5. This study provides direct evidence that Ca2+ release from the sarcoplasmic reticulum, either through ryanodine or inositol 1,4, 5-trisphosphate (InsP3) receptors, increases both cytosolic and mitochondrial [Ca2+] in smooth muscle cells. These results have potential implications both for the role of mitochondria in Ca2+ regulation in smooth muscle, and for understanding how cellular metabolism is regulated.  (+info)

Mitochondrial regulation of the cytosolic Ca2+ concentration and the InsP3-sensitive Ca2+ store in guinea-pig colonic smooth muscle. (5/1585)

1. Mitochondrial regulation of the cytosolic Ca2+ concentration ([Ca2+]c) in guinea-pig single colonic myocytes has been examined, using whole-cell recording, flash photolysis of caged InsP3 and microfluorimetry. 2. Depolarization increased [Ca2+]c and triggered contraction. Resting [Ca2+]c was virtually restored some 4 s after the end of depolarization, a time when the muscle had shortened to 50 % of its fully relaxed length. The muscle then slowly relaxed (t = 17 s). 3. The decline in the Ca2+ transient was monophasic but often undershot or overshot resting levels, depending on resting [Ca2+]c. The extent of the overshoot or undershoot increased with increasing peak [Ca2+]c. 4. Carbonyl cyanide m-chlorophenyl hydrazone (CCCP; 5 microM), which dissipates the mitochondrial proton electrochemical gradient and therefore prevents mitochondrial Ca2+ accumulation, slowed Ca2+ removal at high ( > 300 nM) but not at lower [Ca2+]c and abolished [Ca2+]c overshoots. Oligomycin B (5 microM), which prevents mitchondrial ATP production, affected neither the rate of decline nor the magnitude of the overshoot. 5. During depolarization, the global rhod-2 signal (which represents the mitochondrial matrix Ca2+ concentration, [Ca2+]m) rose slowly in a CCCP-sensitive manner during and for about 3 s after depolarization had ended. [Ca2+]m then slowly decreased over tens of seconds. 6. Inhibition of sarcoplasmic reticulum Ca2+ uptake with thapsigargin (100 nM) reduced the undershoot and increased the overshoot. 7. Flash photolysis of caged InsP3 (20 microM) evoked reproducible increases in [Ca2+]c. CCCP (5 microM) reduced the magnitude of the [Ca2+]c transients evoked by flash photolysis of caged InsP3. Oligomycin B (5 microM) did not reduce the inhibition of the InsP3-induced Ca2+ transient by CCCP thus minimizing the possibility that CCCP lowered ATP levels by reversing the mitochondrial ATP synthase and so reducing SR Ca2+ refilling. 8. While CCCP reduced the magnitude of the InsP3-evoked Ca2+ signal, the internal Ca2+ store content, as assessed by the magnitude of ionomycin-evoked Ca2+ release, did not decrease significantly. 9. [Ca2+]c decline in smooth muscle, following depolarization, may involve mitochondrial Ca2+ uptake. Following InsP3-evoked Ca2+ release, mitochondrial uptake of Ca2+ may regulate the local [Ca2+]c near the InsP3 receptor so maintaining the sensitivity of the InsP3 receptor to release Ca2+ from the SR.  (+info)

Contribution of mitochondrial proton leak to respiration rate in working skeletal muscle and liver and to SMR. (6/1585)

Proton pumping across the mitochondrial inner membrane and proton leak back through the natural proton conductance pathway make up a futile cycle that dissipates redox energy. We measured respiration and average mitochondrial membrane potential in perfused rat hindquarter with maximal tetanic contraction of the left gastrocnemius-soleus-plantaris muscle group, and we estimate that the mitochondrial proton cycle accounted for 34% of the respiration rate of the preparation. Similar measurements in rat hepatocytes given substrates to cause a high rate of gluconeogenesis and ureagenesis showed that the proton cycle accounted for 22% of the respiration rate of these cells. Combining these in vitro values with literature values for the contribution of skeletal muscle and liver to standard metabolic rate (SMR), we calculate that the proton cycle in working muscle and liver may account for 15% of SMR in vivo. Although this value is less than the 20% of SMR we calculated previously using data from resting skeletal muscle and hepatocytes, it is still large, and we conclude that the futile proton cycle is a major contributor to SMR.  (+info)

Calcium-dependent regulation of cytochrome c gene expression in skeletal muscle cells. Identification of a protein kinase c-dependent pathway. (7/1585)

Mitochondrial biogenesis can occur rapidly in mammalian skeletal muscle subjected to a variety of physiological conditions. However, the intracellular signal(s) involved in regulating this process remain unknown. Using nuclearly encoded cytochrome c, we show that its expression in muscle cells is increased by changes in cytosolic Ca2+ using the ionophore A23187. Treatment of myotubes with A23187 increased cytochrome c mRNA expression up to 1.7-fold. Transfection experiments using promoter-chloramphenicol acetyltransferase constructs revealed that this increase could be transcriptionally mediated since A23187 increased chloramphenicol acetyltransferase activity by 2.5-fold. This increase was not changed by KN62, an inhibitor of Ca2+/calmodulin-dependent kinases II and IV, and it was not modified by overexpression of protein kinase A and cAMP response element-binding protein, demonstrating that the A23187 effect was not mediated through Ca2+/calmodulin-dependent kinase- or protein kinase A-dependent pathways. However, treatment of myotubes with staurosporine or 12-O-tetradecanoylphorbol-13-acetate reduced the effect of A23187 on cytochrome c transactivation by 40-50%. Coexpression of the Ca2+-sensitive protein kinase C isoforms alpha and betaII, but not the Ca2+-insensitive delta isoform, exaggerated the A23187-mediated response. The short-term effect of A23187 was mediated in part by mitogen-activated protein kinase (extracellular signal-regulated kinases 1 and 2) since its activation peaked 2 h after A23187 treatment, and cytochrome c transactivation was reduced by PD98089, a mitogen-activated protein kinase/extracellular signal-regulated kinase kinase inhibitor. These results demonstrate the existence of a Ca2+-sensitive, protein kinase C-dependent pathway involved in cytochrome c expression and implicate Ca2+ as a signal in the up-regulation of nuclear genes encoding mitochondrial proteins.  (+info)

Sub maximal oxygen uptake related to fat free mass and lean leg volume in trained runners. (8/1585)

The sub maximal oxygen uptake (VO2) of 32 trained male middle and long distance runners aged 19.5-36.0 years was determined at five treadmill speeds. There was a significant linear relationship (p less than 0.01) between VO2 at each of the treadmill speeds and Fat-Free Mass (FFM) and Lean Leg Volume (LLV). To explain the relationship other factors are considered, the most important of which may be the mechanical configuration of muscle and mitochondrial function.  (+info)

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One of the hallmarks of peripheral insulin resistance is an imbalance in lipid metabolism favoring storage, rather than oxidation, of fatty acids. Lipid accumulation is known to play a causative role in the pathogenesis of insulin resistance (27), and several investigations suggest this effect is secondary to impaired lipid disposal pathways (35, 51, 54, 56-58). Alternatively, endurance exercise training increases whole body fatty acid oxidation, which is linked, in part, to enhanced skeletal muscle mitochondrial content and hence elevated oxidative capacity, an adaptation believed to play a major role in the exercise training-mediated alleviation of insulin resistance (10, 18). Although these studies provide strong evidence indicating a positive relationship between oxidative capacity and improved insulin action, it is largely speculative, since most of the information has been collected from subjects with a preexisting insulin-resistant condition. Obscuring the issue further is the fact that ...
Objective: We examined in insulin resistant muscle if, in contrast to long-standing dogma, mitochondrial fatty acid oxidation is increased, and whether this is attributed to an increased nuclear content of peroxisome proliferator-activated receptor γ co-activator 1α (PGC1α) and the adaptations of specific mitochondrial sub-populations.. Research design and methods: Skeletal muscles from male control and ZDF rats were used to determine; 1) intramuscular lipid distribution, 2) subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondrial morphology, 3) rates of palmitate oxidation in SS and IMF mitochondria, and 4) the sub-cellular localization of PGC1α. Electotransfection of PGC1α-cDNA into lean animals tested the notion that increased nuclear PGC1α preferentially targeted SS mitochondria.. Results: TEM analysis revealed that in ZDF animals the number (+50%), width (+69%) and density (+57%) of SS mitochondria were increased (P,0.05). In contrast, IMF mitochondria remained largely unchanged. ...
The present study showed that early life exposure to large, phospholipid-coated lipid droplets leads to altered expression of markers for mitochondrial oxidative capacity in RP WAT and m. tibialis. Although functional mitochondrial capacity was not measured, these markers suggest that adapted mitochondrial oxidative capacity may underlie the previously reported reduced body fat accumulation in adolescence and adulthood [18-20].. Programming of metabolic health is well established, but possible underlying mechanisms are still largely unknown although many have been suggested. Aberrant mitochondrial function has been suggested in a limited amount of studies as possible link between adverse fetal environment and the development of T2D [22, 34]. Yet, little is known on how nutritional programming may improve lifelong metabolic health and protect against obesity.. In the present study, markers for mitochondrial oxidative capacity appeared to be increased due to the supramolecular structure of milk ...
Reduced skeletal muscle mitochondrial function might be a contributing mechanism to the myopathy and activity based limitations that typically plague patients with peripheral arterial disease (PAD). We hypothesized that mitochondrial dysfunction, myofiber atrophy, and muscle contractile deficits are...
Sigma-Aldrich offers abstracts and full-text articles by [Robert A Jacobs, Anne-Kristine Meinild, Nikolai B Nordsborg, Carsten Lundby].
Regular exercise has proven benefits in preventing and treating type 2 diabetes, but many patients find it tough to meet the American Diabetes Association guidelines of 150 minutes of moderate to vigorous exercise a week. A new study, conducted by researchers at McMaster University, suggests that there could be a better way. In a small proof-of-principle study in eight type 2 diabetes patients, the researchers found that exercising at a very high intensity, but for a mere 30 minutes a week within a 75 minute total time commitment, lowered overall blood sugar concentrations, reduced post-meal blood sugar spikes, and increased skeletal mitochondrial capacity, a marker of metabolic health. The findings suggest that exercising harder, but in a significantly shorter amount of time, could provide benefits similar to longer, but more moderate, activity.. The article is entitled "Low-Volume High-Intensity Interval Training Reduces Hyperglycemia and Increases Muscle Mitochondrial Capacity in Patients ...
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(2009) Rönn et al. PLoS ONE. BACKGROUND: Impaired oxidative capacity of skeletal muscle mitochondria contribute to insulin resistance and type 2 diabetes (T2D). Furthermore, mRNA expression of genes involved in oxidative phosp...
Oxygen consumption (VO2), carbon dioxide production, pulmonary ventilation (Ve), and the respiratory quotient (RER) were measured using an on-line system (Medical Graphics CPX, Saint Paul, Minneapolis, MN, USA) while the subjects breathed through a low-resistance breathing valve. Gases with known VO2 and carbon dioxide consumption concentrations were used for gas analyser calibration. The heart rate was obtained from a continuously recorded electrocardiogram signal. Blood samples were drawn without stasis from a venous catheter in the forearm. In the blood samples the following parameters were assessed: blood lactate, p-pyruvate, free fatty acids (FFA), p-glycerol, p-norepinephrine and p-epinephrine. The blood- lactate levels were immediately measured using an electrolyte metabolite analyser (EML 105; Radiometer, Copenhagen). The samples were immediately frozen for later analyses of FFA, glycerol, p-pyruvate and plasma lactate using Cobas Fara 2 (Roche Diagnostics, Basel, Switzerland), whereas ...
Mitochondria play a key role in the energy metabolism in skeletal muscle. A new concept has emerged suggesting that impaired mitochondrial oxidative capacity in skeletal muscle may be the underlying defect that causes insulin resistance. According to current knowledge, the causes and the underlying molecular mechanisms at the origin of decreased mitochondrial oxidative capacity in skeletal muscle still remain to be elucidated. The present review focuses on recent data investigating these issues in the area of metabolic disorders and describes the potential causes, mechanisms and consequences of mitochondrial dysfunction in the skeletal muscle.
Abstract Peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α has been shown to play critical roles in regulating mitochondria biogenesis, respiration, and muscle oxidative phenotype. Furthermore, reductions in the expression of PGC-1α in muscle have been implicated in the pathogenesis of type 2 diabetes. To determine the effect of increased muscle-specific PGC-1α expression on muscle mitochondrial function and…
TY - JOUR. T1 - Angiotensin II reduces mitochondrial content in skeletal muscle and affects glycemic control. AU - Mitsuishi, Masanori. AU - Miyashita, Kazutoshi. AU - Muraki, Ayako. AU - Itoh, Hiroshi. PY - 2009/3. Y1 - 2009/3. N2 - OBJECTIVE-Blockade of angiotensin (Ang) II has been shown to prevent new-onset type 2 diabetes. We focused on the effects of AngII on muscle mitochondria, especially on their biogenesis, as an underlining mechanism of type 2 diabetes. RESEARCH DESIGN AND METHODS-C2C12 cells and C57bl/6 mice were used to examine roles for AngII in the regulation of muscle mitochondria and to explore whether the effect was mediated by type 1 AngII receptor (AT1R) or type 2 receptor (AT2R). RESULTS-C2C12 cells treated with 10-8-10 -6 mol/l AngII reduced the mitochondrial content associated with downregula- tion of the genes involved in mitochondrial biogenesis. The action of AngII was diminished by blockade of AT2R but not AT1R, whereas overexpression of AT2R augmented the effect. ...
Previous studies examining the effect of different fatty acids on insulin action have reported improved glucose tolerance and insulin tolerance in rodents fed high-fat diets rich in MCFAs compared with LCFAs (11,18,19). Our current study reveals the tissues responsible for the favorable effect of MCFAs on whole-body glucose metabolism, as well as a mechanistic basis for these effects. We have made the intriguing observation that insulin action in skeletal muscle and adipose tissue is preserved at the level of low-fat-fed controls when animals consume a high-fat diet rich in MCFAs. In muscle, the lack of induction of insulin resistance with MCFA high-fat feeding is associated with a substantial increase in mitochondrial oxidative capacity, which is sufficient to prevent lipid accumulation in this tissue. However, the liver of MCFA-fed animals accumulated greater amounts of triglycerides, likely due to upregulation of lipogenic pathways, and as such, hepatic insulin action was reduced after MCFA ...
Although there is no specific treatment for any of the mitochondrial myopathies, physical therapy along with vitamin treatment may extend the range of movement of muscles and improve dexterity.
The current study aims at assessing the impact of Type 1 diabetes and HbA1c on muscle oxygen delivery and on muscle mitochondrial capacity. Our hypothesis is that these both steps of the oxygen cascade might be involved in the aerobic fitness impairment usually observed in poor-controlled patients.. Adults with Type 1 diabetes, aged 18-40 years, without microvascular and macrovascular diabetic complications, will be recruited among patients that regularly attend the unit of diabetology of the University Hospital of Lille and the regional hospital of Roubaix. They will be separated into 2 groups according to their glycaemic control at entrance in the study (HbA1c , 7%, HbA1c , 8%). Subsequently, two healthy control groups (checked by an OGTT) will be selected to strictly match the patients with Type 1 diabetes (age, sex, BMI, number of hours of physical activity per week, tobacco smoking). This is a cross-sectional study including 4 groups.. On their first visit, after the determination of HbA1c, ...
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PMID: 31838512 Open Access Bodis K, Jelenik T, Lundbom J, Markgraf DF, Strom A, Zaharia OP, Karusheva Y, Burkart V, Muessig K, Kupriyanova Y, Ouni M, Wolkersdorfer M, Hwang JH, Ziegler D, Schuermann A, Roden M, Szendroedi J (2019) J Clin Endocrinol Metab Abstract: Impaired adipose tissue (AT) function might induce recent-onset type 2 diabetes (T2D). Understanding AT energy metabolism could yield novel targets for the treatment of T2D. Recently diagnosed male T2D patients and healthy humans (controls, CON) of similar abdominal subcutaneous AT (SAT)-thickness, fat mass and age (n=14 each), underwent hyperinsulinemic-euglycemic clamps with [6,6-2H2]glucose and indirect calorimetry. We assessed mitochondrial efficiency (coupling: state 3/4o; proton leak: state 4o/u) via high-resolution respirometry in superficial (SSAT) and deep (DSAT) SAT-biopsies, hepatocellular lipids (HCL) and fat mass by proton-magnetic-resonance-spectroscopy and -imaging. T2D patients (known diabetes duration: 2.5 [0.1; 5.0] ...
The investigators will determine whether people with high muscle mitochondrial capacity produce higher amount of reactive oxygen species (ROS) on consuming high fat /high glycemic diet and thus exhibit elevated cellular oxidative damage. The investigators previously found that Asian Indian immigrants have high mitochondrial capacity in spite of severe insulin resistance. Somalians are another new immigrant population with rapidly increasing prevalence of diabetes. Both of these groups traditionally consume low caloric density diets, and the investigators hypothesize that when these groups are exposed to high-calorie Western diets, they exhibit increased oxidative stress, oxidative damage, and insulin resistance. The investigators will compare Somalians and NE Americans who are matched for age, BMI, and sex. The investigators will measure ROS production in skeletal muscle following high fat/high glycemic diet vs. healthy diet. The investigators will compare the oxidative damage to proteins, DNA, ...
Cachexia causes metabolic alterations in skeletal muscle mitochondria stimulated by inflammatory imbalance towards pro-inflammatory signaling. Previous work by our group has demonstrated that exercise significantly increases muscle mass in cases of advanced tumors in transgenic mice. Furthermore, we have discovered that the natural product Nexrutine® has anti-inflammatory properties which can be beneficial in protecting mitochondria. PURPOSE: To compare the effects of exercise and Nexrutine® on mitochondrial density in skeletal muscle taken from transgenic adenocarcinoma of the mouse prostate (TRAMP) models. METHODS: This project is a continuation of a larger study investigating the effects of exercise and Nexrutine® on the attenuation of muscle wasting in TRAMP mice. For this analysis, gastrocnemius from 14 TRAMP mice from control (n=5), Nexrutine® (600 mg/kg; n=5), and voluntary wheel running (VWR) groups (n=4) that completed 20 weeks of intervention were used. Mitochondrial activity was
Metabolic reprogramming in skeletal muscles in the human and animal models of amyotrophic lateral sclerosis (ALS) may be an important factor in the diseases progression. We hypothesized that swim training, a modulator of cellular metabolism via changes in muscle bioenergetics and oxidative stress, ameliorates the reduction in muscle strength in ALS mice. In this study, we used transgenic male mice with the G93A human SOD1 mutation B6SJL-Tg (SOD1,sup>G93A,/sup>) 1Gur/J and wild type B6SJL (WT) mice. Mice were subjected to a grip strength test and isolated skeletal muscle mitochondria were used to perform high-resolution respirometry. Moreover, the activities of enzymes involved in the oxidative energy metabolism and total sulfhydryl groups (as an oxidative stress marker) were evaluated in skeletal muscle. ALS reduces muscle strength (-70% between 11 and 15 weeks, p , 0.05), modulates muscle metabolism through lowering citrate synthase (CS) (-30% vs. WT, p = 0.0007) and increasing cytochrome c ...
Mitochondrial myopathies: Diagnosis, exercise intolerance, and treatment options. Plasma malondialdehyde increases transiently after ischemic forearm exercise
Mitochondria play a key role in the pathogenesis of different diseases including the pathologies of the heart. According to the World Health Organization, chronic diseases are responsible for 63% of all deaths in the world, with cardiovascular disease as the leading cause of death. New findings of the cardiac muscle mitochondria functions can be further used to develop new therapeutic strategies. The most important parameters of heart mitochondrial activity are oxidative phosphorylation capacity and mitochondrial membrane potential. With these two properties of mitochondria we can determine the coupling state of respiration and the impact of the mitochondrial substrate on the membrane potential [1]. The Fluorescence module for the Oxygraph-2k (Oroboros Instruments, Innsbruck) combines optical measurement with high-resolution respirometry and with this new technology it is possible to detect changes in both parameters simultaneously. The experiments were carried out in mouse heart homogenate. The ...
Proper function of the endoplasmic reticulum (ER) and mitochondria is crucial for cellular homeostasis, and dysfunction at either site has been linked to pathophysiological states, including metabolic diseases. Although the ER and mitochondria play distinct cellular roles, these organelles also form physical interactions with each other at sites defined as mitochondria-associated ER membranes (MAMs), which are essential for calcium, lipid and metabolite exchange. Here we show that in the liver, obesity leads to a marked reorganization of MAMs resulting in mitochondrial calcium overload, compromised mitochondrial oxidative capacity and augmented oxidative stress. Experimental induction of ER-mitochondria interactions results in oxidative stress and impaired metabolic homeostasis, whereas downregulation of PACS-2 or IP3R1, proteins important for ER-mitochondria tethering or calcium transport, respectively, improves mitochondrial oxidative capacity and glucose metabolism in obese animals. These findings
A brief reminder of the benefits of bicarbonate: Regulation of hydrogen ions (H + ) or pH within homeostatic concentrations is critical for proper physiological function. The factors contributing to the change in muscle pH seen during intense exercise are numerous and the role of each factor remains hotly debated. However, classically it is believed that a large contributor of H + is through the accumulation of lactate produced from glycolysis. Next to internal buffers, which are exhausted relatively quickly, the shuttling of H + and lactate across the sarcolemma is also believed to play an important role in the maintenance of pH during intense exercise. This is due to the extracellular buffering capacity HCO3 - which is believed to promote the efflux of H + from active muscles ( Hollidge-Horvat. 2000; Bishop. 2004 ...
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As noted above, the MTT assay is really a metabolic assay because the MTT molecule needs to enter a cell and get converted to Formazan using NADPH. While the exact mechanism of MTTs metabolism isnt clear, this means the mitochondria needs to be intact and functioning. So, if you add a cytotoxic material which reduces mitochondrial efficiency, you might get weird results. In this case, its useful to also know other live/dead assays. The other major cell viability assays that are used in research include:. Cell Titer Blue: Similar to the MTT Assay, this assay involves incubating cells with resazurin (blue) and forming resorfurin (pink) after the cells metabolize it. Generally the metabolism takes 1-4 hours but it is much more sensitive than the MTT assay because you can measure the product via fluorescence (Ex/Em 560 nm/590 nm). The main advantage of this assay is that you dont need to resolubilize the product in DMF/SDS so its much simpler. This is also a great high throughput assay!. Trypan ...
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Growth restriction impacts on offspring development and increases their risk of disease in adulthood which is exacerbated with second hits. The aim of this study was to investigate if blood pressure, glucose tolerance, and skeletal muscle mitochondrial biogenesis were altered in 12-month-old male and female offspring with prenatal or postnatal growth restriction. Bilateral uterine vessel ligation induced uteroplacental insufficiency and growth restriction in offspring (Restricted). A sham surgery was also performed during pregnancy (Control) and some litters from sham mothers had their litter size reduced (Reduced litter), which restricted postnatal growth. Growth-restricted females only developed hypertension at 12 months, which was not observed in males. In Restricted females only homeostasis model assessment for insulin resistance was decreased, indicating enhanced hepatic insulin sensitivity, which was not observed in males. Plasma leptin was increased only in the Reduced males at 12 ...
Mitochondria are small, energy-producing structures vital to the energy needs of the body. Genetic mutations cause mitochondria to fail to produce the energy needed by cells and organs which can cause severe disease and death. These genetic mutations are likely to be in the mitochondrial DNA (mtDNA), or possibly in the nuclear DNA (nDNA). The goal of this review is to assess the current understanding of mitochondrial diseases. This review focuses on the pathology, causes, risk factors, symptoms, prevalence data, symptomatic treatments, and new research aimed at possible preventions and/or treatments of mitochondrial diseases. Mitochondrial myopathies are mitochondrial diseases that cause prominent muscular symptoms such as muscle weakness and usually present with a multitude of symptoms and can affect virtually all organ systems. There is no cure for these diseases as of today. Treatment is generally supportive and emphasizes symptom management. Mitochondrial diseases occur infrequently and hence
TY - JOUR. T1 - Disruption of Snf3/Rgt2 glucose sensors decreases lifespan and caloric restriction effectiveness through Mth1/Std1 by adjusting mitochondrial efficiency in yeast. AU - Choi, Kyung Mi. AU - Kwon, Young Yon. AU - Lee, Cheol-Koo. PY - 2015/1/30. Y1 - 2015/1/30. N2 - Down-regulation of intracellular nutrient signal pathways was proposed to be a primary mechanism of caloric restriction (CR)-mediated lifespan extension. However, the link between lifespan and glucose sensors in the plasma membrane was poorly understood in yeast. Herein, a mutant that lacked glucose sensors (snf3Δrgt2Δ) had impaired glucose fermentation, showed decreased chronological lifespan (CLS), and reduced CLS extension by CR. The mutant also had reduced mitochondrial efficiency, as inferred by increased mitochondrial superoxide and decreased ATP levels. Mth1 and Std1, which are downstream effectors of the Snf3/Rgt2 pathway, were required for viability through mitochondrial function but not fermentative ...
MCFAs reduce adiposity and preserve insulin action in muscle and adipose, despite inducing steatosis and insulin resistance in the liver. Dietary supplementation with MCFAs may therefore be beneficial for preventing obesity and peripheral insulin resistance.
Diabetes Care. 2010 Oct 26. [Epub ahead of print] Body and Liver Fat Mass Rather Than Muscle Mitochondrial Function Determines Glucose Metabolism in Women with a History of Gestational Diabetes. Prikoszovich T, Winzer C, Schmid AI, Szendroedi J, Chmelik M, Pacini G, Krssák M, Moser E, Funahashi T, Waldhäusl W, Kautzky-Willer A, Roden M. Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria ...
Learn about mitochondria and how to enhance them for better health. Mitochondria are known as the powerhouses of the cell. They are organelles that ac...
Mitochondria are having their time in the spotlight after years of being ignored. Discover everything you need to know about these cellular powerhouses.
Have you heard mitochondria? Do you know there is a way to maximize mitochondira performance in your body to fight aging, check out at Younggolucky.com !
2019 8/15 リンク追記 リファレンスゲノムの構築とキュレーションに多大な努力が注がれている (ref.1-5)。これらのリファレンスアセンブリは結果を比較するための共通の表現を提供し、それらはシーケンスアラインメントとアノテーションを行う広範囲の下流ツ… ...
మైటోకాండ్రియాలు (Mitochondria) కణంలో పాక్షిక స్వతంత్ర ప్రతిపత్తిగల సూక్ష్మాంగాలు. ఇవి స్థూపాకారంలోగాని, గోళాకారంలోగాని ఉంటాయి. ఒక్కొక్కటిగా గాని సమూహాలుగా గాని ఉండవచ్చు. జీవనక్రియలు చురుకుగా సాగే కణాలలో ఇది చాలా అధికసంఖ్యలో ఉంటాయి. ఇవి రెండు పొరలతో ఏర్పడిన సూక్ష్మాంగాలు. ఈ పొరలు కణత్వచాన్ని పోలి ఉంటాయి. దీనివెలుపలి పొర చదునుగా ఉండగా, లోపలి పొర ముడతలుగా ఏర్పడి ఉంటుంది. ఈ ముడతలను ...
TY - JOUR. T1 - Mitochondrial myopathies. AU - DiMauro, S.. AU - Bonilla, E.. AU - Zeviani, M.. AU - Nakagawa, M.. AU - DeVivo, D. C.. PY - 1985. Y1 - 1985. N2 - Mitochondrial myopathies are clinically heterogeneous disorders that can affect multiple systems besides skeletal muscle (mitochondrial encephalomyopathies or cytopathies) and are usually defined by morphological abnormalities of muscle mitochondria. There are a few distinctive syndromes, such as the Kearns-Sayre syndrome; myoclonus epilepsy with ragged-red fibers; and mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes. Biochemically, mitochondrial myopathies can be divided into defects of substrate utilization, oxidation-phosphorylation coupling, and the respiratory chain. Because mitochondria have their own DNA and their own translation and transcription apparatuses, mitochondrial myopathies can be due to defects of either a nuclear or mitochondrial genome and can be transmitted by mendelian or maternal ...
Dietary conditioning of juvenile trout changed the acyl chain composition of mitochondrial phospholipids and the oxidative capacities of muscle mitochondria. Trout were fed three diets differing only in fatty acid (FA) composition. The highly unsaturated 22:6 n-3 (DHA) accounted for 0.4, 14, and 30% of fatty acids in Diets 1, 2 and 3. After 10 weeks of growth, the dietary groups differed markedly in FA composition of mitochondrial phospholipids, with significant dietary effects for virtually all FA. Mean mitochondrial DHA levels were 19, 40 and 33% in trout fed Diets 1, 2 and 3. Mitochondrial oxidative capacities changed with diet, while mitochondrial concentrations of cytochromes and of the adenylate nucleotide translocase (nmol mg(1) protein) did not. Mitochondria from fish fed Diet 1 had higher non-phosphorylating (state 4) rates at 5 degrees C than those fed other diets. When phosphorylating (state 3) rates differed between dietary groups, rates at 5 and 15 degrees C were higher for fish fed the
TY - JOUR. T1 - Interaction of malonyl-CoA and related compounds with mitochondria from different rat tissues. Relationship between ligand binding and inhibition of carnitine palmitoyltransferase I.. AU - Mills, S. E.. AU - Foster, D. W.. AU - McGarry, J. D.. PY - 1983/7/15. Y1 - 1983/7/15. N2 - The sensitivity of carnitine palmitoyltransferase I (CPT I; EC 2.3.1.21) to inhibition by malonyl-CoA and related compounds was examined in isolated mitochondria from liver, heart and skeletal muscle of the rat. In all three tissues the same order of inhibitory potency emerged: malonyl-CoA much greater than succinyl-CoA greater than methylmalonyl-CoA much greater than propionyl-CoA greater than acetyl-CoA. For any given agent, suppression of CPT I activity was much greater in skeletal muscle than in liver, with the heart enzyme having intermediate sensitivity. With skeletal-muscle mitochondria a high-affinity binding site for [14C]malonyl-CoA was readily demonstrable (Kd approx. 25 nM). The ability of ...
Fewer and smaller-sized mitochondria are found in skeletal muscle of insulin-resistant, obese, or T2DM subjects.34-36 The number and size of mitochondria are correlated with mitochondrial oxidative capacity.10 The decreased mitochondrial oxidative capacity accompanies the reduction in expression of mitochondrial proteins encoded by both the mitochondrial genome (cytochrome c oxidase 1) and nucleus (succinate dehydrogenase and pyruvate dehydrogenase).34 The molecular mechanism of mitochondrial biogenesis is driven, in part, through peroxisome proliferator-activated receptor (PPAR) coactivator (PGC)-1. PGC-1α was discovered as a transcriptional regulator of UCP that plays a role in thermogenesis in adipose tissue.37 The expression of PGC-1α is increased on cellular ATP demand, including exercise, cold exposure, and fasting.38-41 PGC-1 is a coactivator of nuclear transcription factors including nuclear respiratory factor (NRF)-1 and PPAR-γ and -α.37,42,43 NRF-1 regulates expression of many ...
This study documents that nNOSμ deficiency, while severely altering the structure and bioenergetics potential of skeletal muscle mitochondria does not impact significantly on the overall resting muscle structure, apart from reducing muscle mass and the CSA of the myofibres of specific muscles. When the muscle is exposed to workloads, however, the consequences of nNOSμ deficiency become apparent, with a significantly reduced resistance of the muscles accompanied by increased sensitivity to exercise-induced damage. This establishes for the first time a link between a deficit in NO signalling, mitochondrial alterations and skeletal muscle impairments.. The first result emerging from our analysis is that nNOSμ deficiency is per se sufficient to induce profound defects in mitochondria, with alterations in mitochondrial distribution, shape, morphology and size accompanied by a latent mitochondrial dysfunction such that energy generation is impaired. Nitric oxide has several key functions in ...
Link: Renshaw G, Devaux J, Hickey A (2015) Event: MiP2015 The thermal limit of cardiac mitochondrial efficiency could be a major determinant of species distribution [1]. The effect of high temperature on brain mitochondria has been less well explored. We examined the effect of 6 temperatures (20°C, 25°C, 30°C, 37°C, 40°C and 45°C) on brain mitochondrial function in homogenates from two Orectolobiform sharks: the Epaulette shark (Hemiscyllium ocellatum), which undergoes metabolic depression in response to the stress provided by oxygen limitation (anoxia) [1,2] and the Grey carpet shark (Chilloscyllium punctatum) which does not respond to anoxia-induced stress by depressing its metabolism [3]. Both of these sharks can occupy shallow reef flats and estuarine habitats potentially exposing them to severe temperature-induced stress during summer low tides. We measured the effect of each temperature on: i) mitochondrial coupling efficiency; ii) non-phosphorylating proton LEAK from mitochondria; ...
Sigma-Aldrich offers abstracts and full-text articles by [E Gnaiger, R Boushel, H Søndergaard, T Munch-Andersen, R Damsgaard, C Hagen, C Díez-Sánchez, I Ara, C Wright-Paradis, P Schrauwen, M Hesselink, J A L Calbet, M Christiansen, J W Helge, B Saltin].
OXPHOS - this site is dedicated to mitochondria research. Theoretical and practical aspects, reagents, protocols, tools, funding agencies, databases, conferences, etc.
Essay, Research Paper Mitochondria are the powerhouse of the cell. Their sole responsibility is to provide energy for the cell. They do this by synthesizing a molecule known as ATP, which the cell uses as energy. Mitochondria are different from the rest of the cell organelles because they contain their own DNA outside the nucleus.
Mitochondria distribution and function in KS keratinocytes. (a and b) Mito Tracker Red staining. Note the smeared mitochondria staining in KS keratinocytes (b)
We explain Mitochondria with video tutorials and quizzes, using our Many Ways(TM) approach from multiple teachers.This lesson will discuss the structure and function of the mitochondria.
Mitochondria are the cells power producers. They convert energy into forms that are usable by the cell. Located in the cytoplasm, they are the sites of
Mitochondria divide by binary fission similar to bacterial cell division. In single-celled eukaryotes, division of mitochondria is linked to cell division. This division must be controlled so that each daughter cell receives at least one mitochondrion. In other eukaryotes (in humans for example), mitochondria may replicate their DNA and divide in response to the energy needs of the cell, rather than in phase with the cell cycle. An individual's mitochondrial genes are not inherited by the same mechanism as nuclear genes. The mitochondria, and therefore the mitochondrial DNA, usually comes from the egg only. The sperm's mitochondria enter the egg, but are marked for later destruction.[8] The egg cell contains relatively few mitochondria, but it is these mitochondria that survive and divide to populate the cells of the adult organism. ...
Mitochondria divide by binary fission similar to bacterial cell division. In single-celled eukaryotes, division of mitochondria is linked to cell division. This division must be controlled so that each daughter cell receives at least one mitochondrion. In other eukaryotes (in humans for example), mitochondria may replicate their DNA and divide in response to the energy needs of the cell, rather than in phase with the cell cycle. An individual's mitochondrial genes are not inherited by the same mechanism as nuclear genes. The mitochondria, and therefore the mitochondrial DNA, usually comes from the egg only. The sperm's mitochondria enter the egg, but are marked for later destruction.[8] The egg cell contains relatively few mitochondria, but it is these mitochondria that survive and divide to populate the cells of the adult organism. ...
The mitochondrion (plural mitochondria) is a membrane boond organelle foond in maist eukaryotic cells (the cells that mak up plants, ainimals, fungi, an mony ither forms o life).[1] Some cells in some multicellular organisms mey houiver lack them (for emsaumple, matur mammalian reid bluid cells). A nummer o unicellular organisms, sic as microsporidia, parabasalids, an diplomonads, hae an aa reduced or transformed thair mitochondria intae ither structurs.[1] Tae date, anerly ane eukaryote, Monocercomonoides, is kent tae hae completely lost its mitochondria.[2] The wird mitochondrion comes frae the Greek μίτος, mitos, "threid", an χονδρίον, chondrion, "granule"[3] or "grain-lik". Mitochondria generate maist o the cell's supplee o adenosine triphosphate (ATP), uised as a soorce o chemical energy.[4] Mitochondria are commonly atween 0.75 an 3 μm in diameter[5] but vairy conseederably in size an structur. Unless speceefically ...
PTEN-induced putative kinase 1 (PINK1) is a mitochondrial serine/threonine-protein kinase encoded by the PINK1 gene. It is thought to protect cells from stress-induced mitochondrial dysfunction. PINK1 activity causes the parkin protein to bind to depolarized mitochondria to induce autophagy of those mitochondria. PINK1 is processed by healthy mitochondria and released to trigger neuron differentiation. Mutations in this gene cause one form of autosomal recessive early-onset Parkinson's disease. PINK1 is synthesized as a 63000 Da protein which is often cleaved by PARL, between the 103-Alanine and the 104-Phenylalanine residues, into a 53000 Da fragment. PINK1 contains an N-terminal mitochondrial localization sequence, a putative transmembrane sequence, a Ser/Thr kinase domain, and a C-terminal regulatory sequence. The protein has been found to localize to the outer membrane of mitochondria, ...
... also has an intermediate role in apoptosis, a controlled form of cell death used to kill cells in the process of development or in response to infection or DNA damage.[20]. Cytochrome c binds to cardiolipin in the inner mitochondrial membrane, thus anchoring its presence and keeping it from releasing out of the mitochondria and initiating apoptosis. While the initial attraction between cardiolipin and cytochrome c is electrostatic due to the extreme positive charge on cytochrome c, the final interaction is hydrophobic, where a hydrophobic tail from cardiolipin inserts itself into the hydrophobic portion of cytochrome c.. During the early phase of apoptosis, mitochondrial ROS production is stimulated, and cardiolipin is oxidized by a peroxidase function of the cardiolipin-cytochrome c complex. The hemoprotein is then detached from the mitochondrial inner membrane and can be extruded into the soluble cytoplasm through pores in the outer ...
Mitochondria are sometimes described as "cellular power plants" because they generate most of the cell's supply of adenosine triphosphate (ATP), a source of chemical energy. Reactive oxygen species (ROS) have been regarded as unwanted by-products of oxidative phosphorylation in mitochondria by the proponents of the free-radical theory of aging promoted by Denham Harman. The free-radical theory suggests that the use of compounds which inactivate ROS, such as antioxidants, would lead to a reduction of oxidative stress and thereby produce an increase in lifespan.[citation needed] ROS may perform an essential and potentially lifespan-promoting role as redox signaling molecules which transduce signals from the mitochondrial compartment to other compartments of the cell.[21] Increased formation of ROS within the mitochondria may cause an adaptive reaction which produces increased stress resistance and a long-term reduction of oxidative stress. ...
... or cytoplasmic inheritance is the transmission of genes that occur outside the nucleus. It is found in most eukaryotes and is commonly known to occur in cytoplasmic organelles such as mitochondria and chloroplasts or from cellular parasites like viruses or bacteria. Mitochondria are organelles which function to transform energy as a result of cellular respiration. Chloroplasts are organelles which function to produce sugars via photosynthesis in plants and algae. The genes located in mitochondria and chloroplasts are very important for proper cellular function, yet the genomes replicate independently of the DNA located in the nucleus, which is typically arranged in chromosomes that only replicate one time preceding cellular division. The extranuclear genomes of mitochondria and chloroplasts however replicate independently of cell division. They replicate in response to a cell's increasing energy needs which adjust during that cell's ...
Metalloendopeptidase OMA1, mitochondrial is an enzyme that in humans is encoded by the OMA1 gene. As a metalloprotease, this protein is a substantial component of the quality control system in the inner membrane of mitochondria. Being activated by enzyme Bax and Bak, mitochondrial protease OMA1 promotes cytochrome c release which subsequently induces apoptosis. The gene OMA1 encodes a metalloprotease, a founding member of a conserved family of membrane-embedded metallopeptidases in mitochondria. The human gene has 9 exons and locates at chromosome band 1p32.2-p32.1 The human protein metalloendopetidase OMA1, mitochondrial is 60.1 kDa in size and composed of 524 amino acids with mitochondrial transition peptide (position 1-13). The mature protein has a theoretical pI of 8.44. The inner membrane of mitochondrial houses two AAA proteases and these membrane-embedded peptidases were termed m- and ...
The group Archamoebae was proposed by Thomas Cavalier-Smith in 1998 as part of the Archezoa, a newly-proposed group to include eukaryotes that had diverged before acquisition of mitochondria and other common eukaryotic cell features.[3][4] Early molecular trees based on rRNA supported this position, placing several Archamoebae genera as separate groups that diverged from other eukaryotes very early on, suggesting that the absence of mitochondria was a primitive condition.[4] However, soon thereafter genetic remnants of mitochondria were found in various Archamoebae, suggesting that these organisms had diverged after the evolution of mitochondria, but had lost their mitochondria over time, and are more closely related to various amoebae and slime molds.[1] ...
Mitochondrial DNA (mtDNA or mDNA) is the DNA in mitochondria.[1] It is inherited only from mothers, though there are a few rare exceptions. Mitochondria are cellular organelles in eukaryotic cells. They convert chemical energy from food into a form that cells can use, adenosine triphosphate (ATP). Mitochondrial DNA is only a small part of the DNA in a eukaryotic cell. Most of the DNA is in the cell nucleus on chromosomes. In plants, the chloroplasts have DNA as well. In humans, mitochondrial DNA codes for 37 genes and with about 16,600 base pairs in a circle. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. The mtDNA in plants is much larger: Arabidopsis has 367 kilobytes. ...
DNA-directed RNA polymerase, mitochondrial is an enzyme that in humans is encoded by the POLRMT gene. This gene encodes a mitochondrial DNA-directed RNA polymerase. The gene product is responsible for mitochondrial gene expression as well as for providing RNA primers for initiation of replication of the mitochondrial genome. Although this polypeptide has the same function as the three nuclear DNA-directed RNA polymerases, it is more closely related to RNA polymerases of bacteriophage and mitochondrial polymerases of lower eukaryotes. GRCh38: Ensembl release 89: ENSG00000099821 - Ensembl, May 2017 GRCm38: Ensembl release 89: ENSMUSG00000020329 - Ensembl, May 2017 "Human PubMed Reference:". "Mouse PubMed Reference:". Tiranti V, Savoia A, Forti F, D'Apolito MF, Centra M, Rocchi M, Zeviani M (Jul 1997). "Identification of the gene encoding the human mitochondrial RNA polymerase (h-mtRPOL) by cyberscreening of ...
Zinc phosphodiesterase ELAC protein 2 is an enzyme that in humans is encoded by the ELAC2 gene. on chromosome 17. It is an endonuclease thought to be involved in mitochondrial tRNA maturation, The ELAC2 gene encodes a protein that is 92 kDa in size and is localized to the mitochondrion and the nucleus. The ELAC2 protein is a zinc phosphodiesterase, which is known to show tRNA 3'-processing endonuclease activity inside the mitochondria. Mitochondria contain their own pool of tRNAs that are involved in the protein translation of 13 subunits of the respiratory chain that are encoded by the mitochondrial genome. ELAC2 functions in the maturation of tRNA by removing a 3'-trailer (extra 3' nucleotides) from tRNA precursors, generating 3' termini of tRNAs. The reaction leaves a 3'-hydroxy group is left at the tRNA end, and a 5'-phosphoryl group at the cleaved, trailing end. The reaction requires zinc ions as co-factors. Variants of the ELAC2 gene ...
మైటోకాండ్రియాలు (Mitochondria) కణంలో పాక్షిక స్వతంత్ర ప్రతిపత్తిగల సూక్ష్మాంగాలు. ఇవి స్థూపాకారంలోగాని, గోళాకారంలోగాని ఉంటాయి. ఒక్కొక్కటిగా గాని సమూహాలుగా గాని ఉండవచ్చు. జీవనక్రియలు చురుకుగా సాగే కణాలలో ఇది చాలా అధికసంఖ్యలో ఉంటాయి. ఇవి రెండు పొరలతో ఏర్పడిన సూక్ష్మాంగాలు. ఈ పొరలు కణత్వచాన్ని పోలి ఉంటాయి. దీనివెలుపలి పొర చదునుగా ఉండగా, లోపలి పొర ముడతలుగా ఏర్పడి ఉంటుంది. ఈ ముడతలను ...
The mechanism by which a 30% decrease in muscle mitochondria has been proposed to cause muscle insulin resistance is an ... This finding argues against the concept that muscle insulin resistance is mediated by a deficiency of muscle mitochondria. We ... decrease in muscle mitochondria is irrelevant in terms of the ability of resting muscle to oxidize fat. ... has been shown to result in increases in skeletal muscle mitochondria (17, 18). In these studies, an increase in muscle ...
Lactate oxidation in human skeletal muscle mitochondria.. [Robert A Jacobs, Anne-Kristine Meinild, Nikolai B Nordsborg, Carsten ... Skeletal muscle biopsies were obtained from vastus lateralis muscle in 16 human subjects. Samples were chemically permeabilized ... The results further demonstrate that human skeletal muscle mitochondria cannot directly oxidize lactate within the ... Here, we analyze the ability of skeletal muscle to respire lactate by using an in situ mitochondrial preparation that leaves ...
Now, a study published March 13 in the journal Cell Reports provides new clues about the cellular mechanisms of aging muscles, ... highlighting the importance of how mitochondria, the powerhouses of the cell, process ADP, which provides energy to cells. ... Most adults reach their peak levels of muscle mass in their late 30s or early 40s. Even for those who exercise regularly, ... Mitochondria may metabolize ADP differently in aging muscle, despite exercise resistance. Cell Press ...
"Disruption of this link prevents the proper communication between mitochondria and the rest of the muscle, making the muscle ... Master Regulator in Mitochondria is Critical for Muscle Function & Repair New study identifies how loss of mitochondrial ... "Control of calcium transport by MICU1 helps to coordinate muscle fibers and their mitochondria," says György Hajnóczky, MD, PhD ... Over time our muscles are able to repair themselves through a complex set of cellular processes within each muscle fiber. New ...
Zidovudine induces molecular, biochemical, and ultrastructural changes in rat skeletal muscle mitochondria.. W Lewis, B ... After 35 d of AZT treatment, selective changes in rat striated muscle were localized ultrastructurally to mitochondria, and ... Decreased muscle mitochondrial (mt) DNA, mtRNA, and decreased mitochondrial polypeptide synthesis in vitro were found in ... and ultrastructural toxic events in skeletal muscle and supported clinical and in vitro findings. ...
This includes for instance the aging-related loss of muscle mass and function [2-9], disuse-induced muscle atrophy [10], ... Given these multifaceted roles of mitochondria in fundamental aspects of skeletal muscle cell physiology, it is not surprising ... Indeed, they play central roles in muscle cell metabolism, energy supply, the regulation of energy-sensitive signaling pathways ... While the importance of normal mitochondrial function is well recognized for muscle physiology, there are important aspects of ...
Mitochondria can also vary in relation to muscle fiber type (40). It can be difficult to assess muscle fiber type at the ... Mitochondria were smaller in skeletal muscle from obese volunteers and type 2 diabetic patients than in muscle from lean ... Mitochondria morphology.. The mitochondria examined by electron microscopy in this study were central mitochondria, mostly ... skeletal muscle mitochondria were smaller in type 2 diabetic and obese subjects than in muscle from lean volunteers (P , 0.01 ...
Skeletal muscle and heart mitochondria were isolated as described previously (10). Skeletal muscle mitochondria were isolated ... Mitochondria contamination estimate in heart, skeletal muscle, and liver mitochondria through five independent experiments. ... Enzymes related to the regulation of the skeletal muscle energy metabolism are highly expressed in skeletal muscle mitochondria ... The lower band corresponding to mitochondria was recovered (11). Preparations of skeletal muscle mitochondria presented a ...
Elongated Mitochondria Constrictions and fission in muscle fatigue Message Subject (Your Name) has sent you a message from ... Elongated Mitochondria Constrictions and fission in muscle fatigue. Manuela Lavorato, Emanuele Loro, Valentina Debattisti, ... Elongated Mitochondria Constrictions and fission in muscle fatigue. Manuela Lavorato, Emanuele Loro, Valentina Debattisti, ... Elongated Mitochondria Constrictions and fission in muscle fatigue. Manuela Lavorato, Emanuele Loro, Valentina Debattisti, ...
Mitochondria isolated from PLIN5 overexpressing muscles did not possess increased fatty acid respiration. Interestingly though ... This prompted us to examine PLIN5 protein expression in skeletal muscle mitochondria by means of immunogold electron microscopy ... Here, we investigated the role of PLIN5 in fat oxidation in skeletal muscle. In human skeletal muscle, we observed that PLIN5 ( ... The lipid droplet coat protein perilipin 5 also localizes to muscle mitochondria. ...
"Aging is characterized by a progressive loss of muscle mass and muscle strength. Declines in skeletal muscle mitochondria are ... A Review of Skeletal Muscle Mitochondria in Aging. Permalink No Comments Yet Add a Comment Posted by Reason ... Animal and human studies typically show that skeletal muscle mitochondria are altered with aging, including increased mutations ... Mitochondria are the major producers of reactive oxygen species, which damage DNA, proteins, and lipids if not rapidly quenched ...
Lack of dystrophin is associated with altered integration of the mitochondria and ATPases in slow-twitch muscle cells of MDX ... The potential role of dystrophin-mediated control of systems integrating mitochondria with ATPases was assessed in muscle cells ... whereas the other muscles appeared normal in this group. Irrespective of muscle type, the absence of dystrophin had no effect ... In conclusion, our data indicate that in slow-twitch muscle cells, the absence of dystrophin is associated with the ...
Mitochondria - The Powerhouse Of The Body & Mind. Articles , Genetics , Mind + Muscle 101 Series ... The amount of energy and alertness that we have is decided by how well the mitochondria function. Mitochondria are known ... The mitochondria are used to create the energy that we use on a daily basis. When energy is used, and the need for new energy ... Mind and Muscle is dedicated to one single idea. That it is possible to completely recast the genetic expression of ones body. ...
Disruption of Mitochondria-Associated Endoplasmic Reticulum Membrane (MAM) Integrity Contributes to Muscle Insulin Resistance ... Disruption of Mitochondria-Associated Endoplasmic Reticulum Membrane (MAM) Integrity Contributes to Muscle Insulin Resistance ... Disruption of Mitochondria-Associated Endoplasmic Reticulum Membrane (MAM) Integrity Contributes to Muscle Insulin Resistance ... Disruption of Mitochondria-Associated Endoplasmic Reticulum Membrane (MAM) Integrity Contributes to Muscle Insulin Resistance ...
Measurement of the energy-generating capacity of human muscle mitochondria: diagnostic procedure and application to human ... Muscle, 81%) 24 (M) Complex V MT-ATP6 (Muscle, 77%) T8993G; (muscle, ,95%) 25 (F) Complex V MT-ATP6 (Muscle, 50%) T8993G; ( ... Muscle, 2%) 18 (F) PDHc PDHA1 (Muscle, 68%; fibroblast, 82%) del926 AAGTAAG PDHc-E1 (Muscle, 64%) 19 (F) PDHc PDHA1 (Muscle, 89 ... muscle, 81%) (Muscle, 18%) Complex III (Muscle, 84%) 13 (F) Complex II Genetic defect unknown (Muscle, 42%; fibroblast, 38%) 14 ...
PubMed journal article Ketogenic diet increases mitochondria volume in the liver and skeletal muscle without altering oxidative ... Ketogenic diet increases mitochondria volume in the liver and skeletal muscle without altering oxidative stress markers in rats ... "Ketogenic Diet Increases Mitochondria Volume in the Liver and Skeletal Muscle Without Altering Oxidative Stress Markers in Rats ... Ketogenic diet increases mitochondria volume in the liver and skeletal muscle without altering oxidative stress markers in rats ...
The time course of changes in the properties of mitochondria from oxidative muscle of rainbow trout was examined during warm ( ... Time course of the response of mitochondria from oxidative muscle during thermal acclimation of rainbow trout, Oncorhynchus ... Time course of the response of mitochondria from oxidative muscle during thermal acclimation of rainbow trout, Oncorhynchus ... Time course of the response of mitochondria from oxidative muscle during thermal acclimation of rainbow trout, Oncorhynchus ...
Effect of long-term exercise on human muscle mitochondria. In: Pernow B, Saltin B (eds) Muscle metabolism during exercise. ... Mitochondria changes in human muscle after prolonged exercise, endurance training and selenium supplementation. *A. J. Zamora2 ... The number of mitochondria per area (QA) and the relative surface occupied by the total mitochondria profile area (A A) were ... Zamora, A.J., Tessier, F., Marconnet, P. et al. Mitochondria changes in human muscle after prolonged exercise, endurance ...
Mitochondria provide the energy to power contraction of the muscle. ... Cardiac muscle stained for mitochondria. Mitochondria provide the energy to power contraction of the muscle.. NIMR, Francis ... Credit: Cardiac muscle stained for mitochondria. Mitochondria provide the energy to power contraction of the muscle. Credit: ...
... present a modification of a previously reported method that allows for the isolation of high quality and purified mitochondria ... The isolation of skeletal muscle mitochondria often requires harsh methods to liberate mitochondria from surrounding connective ... Given that skeletal muscle mitochondria are involved in many pathological conditions, the measurement of O2 consumption in ... Dysfunctional skeletal muscle mitochondria play a role in altered metabolism observed with aging, obesity and Type II diabetes ...
Morphometric analysis of mitochondria in skeletal muscles and heart of 6- and 60-month-old naked mole rats ( Heterocephalus ... Morphometric analysis of mitochondria in skeletal muscles and heart of 6- and 60-month-old naked mole rats (Heterocephalus ... Del Campo, A., Jaimovich, E., and Tevy, M. F. (2016) Mitochondria in the aging muscles of flies and mice: new perspectives for ... Carter, H. N., Chen, C. C. W., and Hood, D. A. (2015) Mitochondria, muscle health, and exercise with advancing age, Physiology ...
Both calcium signalling and neurotransmitter release are affected by mitochondria function but the effect of mitochondria on ... Dysfunction of mitochondria is known to impact on the pathogenesis of motor neuron diseases, often in the pre-symptomatic ... The differentiation of hiPSCs into muscle cells will lead to further replacement of ~200 chicks or ~100 mice per year in Dr ... in hIPSC differentiation protocols to generate motor neuron-muscle cultures to replace rat models in study of mitochondria on ...
Age‐related endothelial dysfunction in human skeletal muscle feed arteries: the role of free radicals derived from mitochondria ...
... pyruvate dehydrogenase and on PDHA content is less marked in skeletal-muscle mitochondria than in cardiac-muscle mitochondria. ... significance in pyruvate dehydrogenase interconversion in skeletal-muscle mitochondria than in cardiac-muscle mitochondria. ... Effect of fatty acids and ketones on the activity of pyruvate dehydrogenase in skeletal-muscle mitochondria. B Ashour, R G ... This may reflect the less active oxidation of palmitoylcarnitine by skeletal-muscle mitochondria, as judged by State-3 rates of ...
Abnormal Mitochondria Organization and Oxidative Activity in the Palate Muscles of Long-Term Snorers with Obstructive Sleep ... Palate muscle, Mitochondria, Capillaries, Snoring, Sleep apnea, Obstructive sleep apnea syndrome National Category Medical and ... a low capillary supply and signs of impaired oxidative activity suggest that muscle dysfunction of the palate muscles in long- ... The cause of these abnormalities remains unclear, but local muscle and nerve trauma due to vibration and stretch is a possible ...
  • 15 ) recently reported that a high-fat diet resulted in increases in mitochondrial biogenesis and fatty acid oxidative capacity in skeletal muscle of mice. (pnas.org)
  • Overexpression of peroxisome proliferator-activated receptor (PPAR)δ in muscles of transgenic mice, or activation of PPARδ in skeletal muscle in vivo by using a specific PPARδ activator, has been shown to result in increases in skeletal muscle mitochondria ( 17 , 18 ). (pnas.org)
  • The researchers provoked muscle damage in mice by having them run on a downhill treadmill, which is more strenuous than a running wheel. (jefferson.edu)
  • The researchers found that MICU1-deficient mice had more dye in the muscle, indicating that their ability to undergo muscle membrane repair was compromised. (jefferson.edu)
  • Lack of dystrophin is associated with altered integration of the mitochondria and ATPases in slow-twitch muscle cells of MDX mice. (nih.gov)
  • Laser confocal microscopy revealed disorganized mitochondrial arrays in m. gastrocnemius in MDX mice, whereas the other muscles appeared normal in this group. (nih.gov)
  • Collectively, our data reveal a new role of MAM integrity in insulin action of skeletal muscle and highlight MAM disruption as an essential subcellular alteration associated with muscle insulin resistance in mice and humans. (diabetesjournals.org)
  • The differentiation of hiPSCs into muscle cells will lead to further replacement of ~200 chicks or ~100 mice per year in Dr Rigby's experiments. (nc3rs.org.uk)
  • Proton conductance through endogenously activated UCP3 was calculated as the difference in leak between mitochondria from wild-type and Ucp3-knockout mice, and was found to be inhibited by carboxyatractylate and bongkrekate, but not GDP. (cam.ac.uk)
  • Proton conductance in mitochondria from Ucp3-knockout mice was strongly inhibited by carboxyatractylate, bongkrekate and partially by GDP. (cam.ac.uk)
  • Changes in isoform composition, gene expression of titin and nebulin, and isoform composition of myosin heavy chains as well as changes in titin phosphorylation level in skeletal (m. gastrocnemius, m. tibialis anterior, and m. psoas) and cardiac muscles of mice were studied after a 30-day-long space flight onboard the Russian spacecraft "BION-M" number 1. (hindawi.com)
  • The observed changes are discussed in the context of their role in the contractile activity of striated muscles of mice under conditions of weightlessness. (hindawi.com)
  • The mitochondria of these mito-mSOD1 mice contained about the same amount of mSOD1 seen in mitochondria in the standard SOD1-G93A model with unrestricted mSOD1 targeting. (alzforum.org)
  • In biochemistry experiments, mitochondria isolated from the brains of mito-mSOD1 mice were more sensitive to an uncoupling agent, failed to retain calcium ions, and had reduced activity of the respiratory enzyme cytochrome oxidase, as compared to mitochondria from non-transgenic mice. (alzforum.org)
  • Deletion of Mapk14 (p38α-encoding gene) in the skeletal muscle of mdx- (lacking dystrophin) or sgcd- (δ-sarcoglycan-encoding gene) null mice resulted in a significant reduction in pathology up to 6 months of age. (nih.gov)
  • We also generated MAPK kinase 6 (MKK6) muscle-specific transgenic mice to model heightened p38α disease signaling that occurs in dystrophic muscle, which resulted in severe myofiber necrosis and many hallmarks of muscular dystrophy. (nih.gov)
  • Indeed, muscle-specific deletion of Bax, but not the apoptosis regulatory gene Tp53 (encoding p53), significantly reduced dystrophic pathology in the muscles of MKK6 transgenic mice. (nih.gov)
  • We interpret our findings as evidence that raising free fatty acids results in an increase in mitochondria by activating PPARδ, which mediates a posttranscriptional increase in PGC-1α. (pnas.org)
  • Addition of Ca2+-EGTA buffers stabilizing pCa values of 6.48 or lower gave near-maximal values of PDHA content, irrespective of the presence of fatty acids or ketones when mitochondria were incubated under the same conditions used for the flux studies, i.e. at low concentrations of pyruvate. (biochemj.org)
  • The initial purpose of the present study was to determine whether the more modest increase in FFA induced by a high-fat diet also results in increased mitochondrial biogenesis with an increase in the capacity of muscle to oxidize fat. (pnas.org)
  • Despite the emerging role of mitochondria in endothelial pathophysiological alteration in aging and the relationship between mitochondrial biogenesis and mitochondrial ROS production, there are no studies extant investigating aging-induced alterations in vascular mitochondrial biogenesis. (physiology.org)