Anoxia: Relatively complete absence of oxygen in one or more tissues.Hypoxia, Brain: A reduction in brain oxygen supply due to ANOXEMIA (a reduced amount of oxygen being carried in the blood by HEMOGLOBIN), or to a restriction of the blood supply to the brain, or both. Severe hypoxia is referred to as anoxia, and is a relatively common cause of injury to the central nervous system. Prolonged brain anoxia may lead to BRAIN DEATH or a PERSISTENT VEGETATIVE STATE. Histologically, this condition is characterized by neuronal loss which is most prominent in the HIPPOCAMPUS; GLOBUS PALLIDUS; CEREBELLUM; and inferior olives.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.TurtlesCell Hypoxia: A condition of decreased oxygen content at the cellular level.Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Artemia: A genus of CRUSTACEA of the order ANOSTRACA, found in briny pools and lakes and often cultured for fish food. It has 168 chromosomes and differs from most crustaceans in that its blood contains hemoglobin.Pyruvate Decarboxylase: Catalyzes the decarboxylation of an alpha keto acid to an aldehyde and carbon dioxide. Thiamine pyrophosphate is an essential cofactor. In lower organisms, which ferment glucose to ethanol and carbon dioxide, the enzyme irreversibly decarboxylates pyruvate to acetaldehyde. EC 22.214.171.124.Cotyledon: A part of the embryo in a seed plant. The number of cotyledons is an important feature in classifying plants. In seeds without an endosperm, they store food which is used in germination. In some plants, they emerge above the soil surface and become the first photosynthetic leaves. (From Concise Dictionary of Biology, 1990)Sodium Cyanide: A highly poisonous compound that is an inhibitor of many metabolic processes and is used as a test reagent for the function of chemoreceptors. It is also used in many industrial processes.Potassium Cyanide: A highly poisonous compound that is an inhibitor of many metabolic processes, but has been shown to be an especially potent inhibitor of heme enzymes and hemeproteins. It is used in many industrial processes.Potamogetonaceae: A plant family of the order Najadales, subclass Alismatidae, class Liliopsida (monocotyledons).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.Carps: Common name for a number of different species of fish in the family Cyprinidae. This includes, among others, the common carp, crucian carp, grass carp, and silver carp.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.Killifishes: Small oviparous fishes in the family Cyprinodontidae, usually striped or barred black. They are much used in mosquito control.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.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.Iridaceae: A monocot plant family of the Liliopsida class. It is classified by some in the Liliales order and some in the Asparagales order.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)Araliaceae: The ginseng plant family of the order Apiales, subclass Rosidae, class Magnoliopsida. Leaves are generally alternate, large, and compound. Flowers are five-parted and arranged in compound flat-topped umbels. The fruit is a berry or (rarely) a drupe (a one-seeded fruit). It is well known for plant preparations used as adaptogens (immune support and anti-fatigue).Hepatopancreas: A primitive form of digestive gland found in marine ARTHROPODS, that contains cells similar to those found in the mammalian liver (HEPATOCYTES), and the PANCREAS.Dinitrophenols: Organic compounds that contain two nitro groups attached to a phenol.Acorus: A plant genus of the family ACORACEAE, order Arales, subclass Arecidae most notable for Acorus calamus L. root which contains asarone and has been used in TRADITIONAL MEDICINE.L-Lactate Dehydrogenase: A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.Oryza sativa: Annual cereal grass of the family POACEAE and its edible starchy grain, rice, which is the staple food of roughly one-half of the world's population.Aerobiosis: Life or metabolic reactions occurring in an environment containing oxygen.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)Time Factors: Elements of limited time intervals, contributing to particular results or situations.VeratrineAmobarbital: A barbiturate with hypnotic and sedative properties (but not antianxiety). Adverse effects are mainly a consequence of dose-related CNS depression and the risk of dependence with continued use is high. (From Martindale, The Extra Pharmacopoeia, 30th ed, p565)Echinochloa: A plant genus of the family POACEAE that is grown mainly as a hay crop.Protoveratrines: Mixtures of closely related hypotensive alkaloids from Veratrum album (Liliaceae). They have been used in the treatment of hypertension but have largely been replaced by drugs with fewer adverse effects.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.Energy Metabolism: The chemical reactions involved in the production and utilization of various forms of energy in cells.Sagittaria: A plant genus of the family ALISMATACEAE that grows in salty marshes and is used for phytoremediation of oil spills. The unisexual flowers have 3 sepals and 3 petals. Members contain trifoliones (DITERPENES).Nystatin: Macrolide antifungal antibiotic complex produced by Streptomyces noursei, S. aureus, and other Streptomyces species. The biologically active components of the complex are nystatin A1, A2, and A3.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.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.Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone: A proton ionophore that is commonly used as an uncoupling agent in biochemical studies.Hagfishes: Common name for a family of eel-shaped jawless fishes (Myxinidae), the only family in the order MYXINIFORMES. They are not true vertebrates.Labyrinthine Fluids: Fluids found within the osseous labyrinth (PERILYMPH) and the membranous labyrinth (ENDOLYMPH) of the inner ear. (From Gray's Anatomy, 30th American ed, p1328, 1332)Endolymphatic Duct: The part of the membranous labyrinth that traverses the bony vestibular aqueduct and emerges through the bone of posterior cranial fossa (CRANIAL FOSSA, POSTERIOR) where it expands into a blind pouch called the endolymphatic sac.Sodium: A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.Kymography: The recording of wavelike motions or undulations. It is usually used on arteries to detect variations in blood pressure.Lactic Acid: A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)Iodoacetates: Iodinated derivatives of acetic acid. Iodoacetates are commonly used as alkylating sulfhydryl reagents and enzyme inhibitors in biochemical research.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.Plant Roots: The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)Iodoacetic Acid: A derivative of ACETIC ACID that contains one IODINE atom attached to its methyl group.Carbohydrate Metabolism: Cellular processes in biosynthesis (anabolism) and degradation (catabolism) of CARBOHYDRATES.Embryo, Nonmammalian: The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.Cyanides: Inorganic salts of HYDROGEN CYANIDE containing the -CN radical. The concept also includes isocyanides. It is distinguished from NITRILES, which denotes organic compounds containing the -CN radical.Hermaphroditic Organisms: Animals and plants which have, as their normal mode of reproduction, both male and female sex organs in the same individual.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)Lactates: Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.Sodium Lactate: The sodium salt of racemic or inactive lactic acid. It is a hygroscopic agent used intravenously as a systemic and urinary alkalizer.Adenine NucleotidesAcidosis: A pathologic condition of acid accumulation or depletion of base in the body. The two main types are RESPIRATORY ACIDOSIS and metabolic acidosis, due to metabolic acid build up.Heart: The hollow, muscular organ that maintains the circulation of the blood.Extracellular Space: Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.Glyburide: An antidiabetic sulfonylurea derivative with actions similar to those of chlorpropamide.Snails: Marine, freshwater, or terrestrial mollusks of the class Gastropoda. Most have an enclosing spiral shell, and several genera harbor parasites pathogenic to man.Hypoxia-Inducible Factor 1: A basic helix-loop-helix transcription factor that plays a role in APOPTOSIS. It is composed of two subunits: ARYL HYDROCARBON RECEPTOR NUCLEAR TRANSLOCATOR and HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT.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.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.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.Oxidative Phosphorylation: Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.Hippocampus: A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Perfusion: Treatment process involving the injection of fluid into an organ or tissue.Ouabain: A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.Acid-Base Equilibrium: The balance between acids and bases in the BODY FLUIDS. The pH (HYDROGEN-ION CONCENTRATION) of the arterial BLOOD provides an index for the total body acid-base balance.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.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.Ethanol: A clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is widely used as a solvent and preservative in pharmaceutical preparations as well as serving as the primary ingredient in ALCOHOLIC BEVERAGES.Brain Stem: The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.Animals, Newborn: Refers to animals in the period of time just after birth.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.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.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Glucosyltransferases: Enzymes that catalyze the transfer of glucose from a nucleoside diphosphate glucose to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.Alcohol Dehydrogenase: A zinc-containing enzyme which oxidizes primary and secondary alcohols or hemiacetals in the presence of NAD. In alcoholic fermentation, it catalyzes the final step of reducing an aldehyde to an alcohol in the presence of NADH and hydrogen.Seedling: Very young plant after GERMINATION of SEEDS.Nitrogen: An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.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).Antimetabolites: Drugs that are chemically similar to naturally occurring metabolites, but differ enough to interfere with normal metabolic pathways. (From AMA Drug Evaluations Annual, 1994, p2033)Sharks: A group of elongate elasmobranchs. Sharks are mostly marine fish, with certain species large and voracious.Germination: The initial stages of the growth of SEEDS into a SEEDLINGS. The embryonic shoot (plumule) and embryonic PLANT ROOTS (radicle) emerge and grow upwards and downwards respectively. Food reserves for germination come from endosperm tissue within the seed and/or from the seed leaves (COTYLEDON). (Concise Dictionary of Biology, 1990)Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.Acidosis, Lactic: Acidosis caused by accumulation of lactic acid more rapidly than it can be metabolized. It may occur spontaneously or in association with diseases such as DIABETES MELLITUS; LEUKEMIA; or LIVER FAILURE.Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Ischemia: A hypoperfusion of the BLOOD through an organ or tissue caused by a PATHOLOGIC CONSTRICTION or obstruction of its BLOOD VESSELS, or an absence of BLOOD CIRCULATION.Fermentation: Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.Tolbutamide: A sulphonylurea hypoglycemic agent with actions and uses similar to those of CHLORPROPAMIDE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p290)Adenosine: A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.Salt Gland: A compound tubular gland, located around the eyes and nasal passages in marine animals and birds, the physiology of which figures in water-electrolyte balance. The Pekin duck serves as a common research animal in salt gland studies. A rectal gland or rectal salt gland in the dogfish shark is attached at the junction of the intestine and cloaca and aids the kidneys in removing excess salts from the blood. (Storer, Usinger, Stebbins & Nybakken: General Zoology, 6th ed, p658)Acids: Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. (Grant & Hackh's Chemical Dictionary, 5th ed)Fructose-Bisphosphate Aldolase: An enzyme of the lyase class that catalyzes the cleavage of fructose 1,6-biphosphate to form dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. The enzyme also acts on (3S,4R)-ketose 1-phosphates. The yeast and bacterial enzymes are zinc proteins. (Enzyme Nomenclature, 1992) E.C. 126.96.36.199.Hypoxia-Inducible Factor 1, alpha Subunit: Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.Hypoglossal Nerve: The 12th cranial nerve. The hypoglossal nerve originates in the hypoglossal nucleus of the medulla and supplies motor innervation to all of the muscles of the tongue except the palatoglossus (which is supplied by the vagus). This nerve also contains proprioceptive afferents from the tongue muscles.Mitochondria, Heart: The mitochondria of the myocardium.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)Phosphates: Inorganic salts of phosphoric acid.UtahHot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.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.Optic Nerve: The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.Free Radicals: Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.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.2,4-Dinitrophenol: A toxic dye, chemically related to trinitrophenol (picric acid), used in biochemical studies of oxidative processes where it uncouples oxidative phosphorylation. It is also used as a metabolic stimulant. (Stedman, 26th ed)Asphyxia: A pathological condition caused by lack of oxygen, manifested in impending or actual cessation of life.Nitrites: Salts of nitrous acid or compounds containing the group NO2-. The inorganic nitrites of the type MNO2 (where M=metal) are all insoluble, except the alkali nitrites. The organic nitrites may be isomeric, but not identical with the corresponding nitro compounds. (Grant & Hackh's Chemical Dictionary, 5th ed)Adenosine Monophosphate: Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position.Deoxyglucose: 2-Deoxy-D-arabino-hexose. An antimetabolite of glucose with antiviral activity.Acclimatization: Adaptation to a new environment or to a change in the old.Heat-Shock Proteins: Proteins which are synthesized in eukaryotic organisms and bacteria in response to hyperthermia and other environmental stresses. They increase thermal tolerance and perform functions essential to cell survival under these conditions.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Naphthols: Naphthalene derivatives carrying one or more hydroxyl (-OH) groups at any ring position. They are often used in dyes and pigments, as antioxidants for rubber, fats, and oils, as insecticides, in pharmaceuticals, and in numerous other applications.Adrenergic beta-2 Receptor Antagonists: Drugs that bind to and block the activation of ADRENERGIC BETA-2 RECEPTORS.Caenorhabditis elegans: A species of nematode that is widely used in biological, biochemical, and genetic studies.Potassium Channels: Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Cold Temperature: An absence of warmth or heat or a temperature notably below an accustomed norm.Cobalt: A trace element that is a component of vitamin B12. It has the atomic symbol Co, atomic number 27, and atomic weight 58.93. It is used in nuclear weapons, alloys, and pigments. Deficiency in animals leads to anemia; its excess in humans can lead to erythrocytosis.Myocardial Reperfusion Injury: Damage to the MYOCARDIUM resulting from MYOCARDIAL REPERFUSION (restoration of blood flow to ischemic areas of the HEART.) Reperfusion takes place when there is spontaneous thrombolysis, THROMBOLYTIC THERAPY, collateral flow from other coronary vascular beds, or reversal of vasospasm.Geologic Sediments: A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)Kinetics: The rate dynamics in chemical or physical systems.Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.Organisms, Genetically Modified: Organisms whose GENOME has been changed by a GENETIC ENGINEERING technique.Carotid Body: A small cluster of chemoreceptive and supporting cells located near the bifurcation of the internal carotid artery. The carotid body, which is richly supplied with fenestrated capillaries, senses the pH, carbon dioxide, and oxygen concentrations in the blood and plays a crucial role in their homeostatic control.Kidney Tubules, Proximal: The renal tubule portion that extends from the BOWMAN CAPSULE in the KIDNEY CORTEX into the KIDNEY MEDULLA. The proximal tubule consists of a convoluted proximal segment in the cortex, and a distal straight segment descending into the medulla where it forms the U-shaped LOOP OF HENLE.Rhizome: Root-like underground horizontal stem of plants that produces shoots above and roots below. Distinguished from true roots which don't have buds and nodes. Similar to true roots in being underground and thickened by storage deposits.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).Electron Probe Microanalysis: Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Microtomy: The technique of using a microtome to cut thin or ultrathin sections of tissues embedded in a supporting substance. The microtome is an instrument that hold a steel, glass or diamond knife in clamps at an angle to the blocks of prepared tissues, which it cuts in sections of equal thickness.Myocardial Contraction: Contractile activity of the MYOCARDIUM.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Hydroxy Acids: Organic compounds containing both the hydroxyl and carboxyl radicals.Decanoic Acids: 10-carbon saturated monocarboxylic acids.Sodium-Calcium Exchanger: An electrogenic ion exchange protein that maintains a steady level of calcium by removing an amount of calcium equal to that which enters the cells. It is widely distributed in most excitable membranes, including the brain and heart.Myocardial Ischemia: A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (CORONARY ARTERY DISEASE), to obstruction by a thrombus (CORONARY THROMBOSIS), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Severe interruption of the blood supply to the myocardial tissue may result in necrosis of cardiac muscle (MYOCARDIAL INFARCTION).Ischemic Preconditioning: A technique in which tissue is rendered resistant to the deleterious effects of prolonged ISCHEMIA and REPERFUSION by prior exposure to brief, repeated periods of vascular occlusion. (Am J Physiol 1995 May;268(5 Pt 2):H2063-7, Abstract)Electric Stimulation: Use of electric potential or currents to elicit biological responses.Fluorometry: An analytical method for detecting and measuring FLUORESCENCE in compounds or targets such as cells, proteins, or nucleotides, or targets previously labeled with FLUORESCENCE AGENTS.Freezing: Liquids transforming into solids by the removal of heat.Biological Transport, Active: The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.Luminescence: Emission of LIGHT when ELECTRONS return to the electronic ground state from an excited state and lose the energy as PHOTONS. It is sometimes called cool light in contrast to INCANDESCENCE. LUMINESCENT MEASUREMENTS take advantage of this type of light emitted from LUMINESCENT AGENTS.Glutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.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.Gene Expression Regulation, Enzymologic: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.Diazoxide: A benzothiadiazine derivative that is a peripheral vasodilator used for hypertensive emergencies. It lacks diuretic effect, apparently because it lacks a sulfonamide group.Glutamates: Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.Nitric Oxide: A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.Brain Ischemia: Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.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.Stress, Physiological: The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.Nitrates: Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.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.Plant Stems: Parts of plants that usually grow vertically upwards towards the light and support the leaves, buds, and reproductive structures. (From Concise Dictionary of Biology, 1990)Apnea: A transient absence of spontaneous respiration.Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Hypoxanthine: A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.Oceans and Seas: A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic).Nitrate Reductase: An enzyme that catalyzes the oxidation of nitrite to nitrate. It is a cytochrome protein that contains IRON and MOLYBDENUM.Purinergic Antagonists: Drugs that bind to and block the activation of PURINERGIC RECEPTORS.Phosphocreatine: An endogenous substance found mainly in skeletal muscle of vertebrates. It has been tried in the treatment of cardiac disorders and has been added to cardioplegic solutions. (Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1996)Asphyxia Neonatorum: Respiratory failure in the newborn. (Dorland, 27th ed)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)Phosphofructokinase-1: An allosteric enzyme that regulates glycolysis by catalyzing the transfer of a phosphate group from ATP to fructose-6-phosphate to yield fructose-1,6-bisphosphate. D-tagatose- 6-phosphate and sedoheptulose-7-phosphate also are acceptors. UTP, CTP, and ITP also are donors. In human phosphofructokinase-1, three types of subunits have been identified. They are PHOSPHOFRUCTOKINASE-1, MUSCLE TYPE; PHOSPHOFRUCTOKINASE-1, LIVER TYPE; and PHOSPHOFRUCTOKINASE-1, TYPE C; found in platelets, brain, and other tissues.Deferoxamine: Natural product isolated from Streptomyces pilosus. It forms iron complexes and is used as a chelating agent, particularly in the mesylate form.Electron Transport Chain Complex Proteins: A complex of enzymes and PROTON PUMPS located on the inner membrane of the MITOCHONDRIA and in bacterial membranes. The protein complex provides energy in the form of an electrochemical gradient, which may be used by either MITOCHONDRIAL PROTON-TRANSLOCATING ATPASES or BACTERIAL PROTON-TRANSLOCATING ATPASES.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Evoked Potentials: Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.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)Oncorhynchus mykiss: A large stout-bodied, sometimes anadromous, TROUT found in still and flowing waters of the Pacific coast from southern California to Alaska. It has a greenish back, a whitish belly, and pink, red, or lavender stripes on the sides, with usually a sprinkling of black dots. It is highly regarded as a sport and food fish. Its former name was Salmo gairdneri. The sea-run rainbow trouts are often called steelheads. Redband trouts refer to interior populations of rainbows.Pacific OceanScopolamine Hydrobromide: An alkaloid from SOLANACEAE, especially DATURA and SCOPOLIA. Scopolamine and its quaternary derivatives act as antimuscarinics like ATROPINE, but may have more central nervous system effects. Among the many uses are as an anesthetic premedication, in URINARY INCONTINENCE, in MOTION SICKNESS, as an antispasmodic, and as a mydriatic and cycloplegic.
Quantification of tumour vasculature and hypoxia by immunohistochemical staining and HbO2 saturation measurements. (1/8649)Despite the possibility that tumour hypoxia may limit radiotherapeutic response, the underlying mechanisms remain poorly understood. A new methodology has been developed in which information from several sophisticated techniques is combined and analysed at a microregional level. First, tumour oxygen availability is spatially defined by measuring intravascular blood oxygen saturations (HbO2) cryospectrophotometrically in frozen tumour blocks. Second, hypoxic development is quantified in adjacent sections using immunohistochemical detection of a fluorescently conjugated monoclonal antibody (ELK3-51) to a nitroheterocyclic hypoxia marker (EF5), thereby providing information relating to both the oxygen consumption rates and the effective oxygen diffusion distances. Third, a combination of fluorescent (Hoechst 33342 or DiOC7(3)) and immunohistological (PECAM-1/CD31) stains is used to define the anatomical vascular densities and the fraction of blood vessels containing flow. Using a computer-interfaced microscope stage, image analysis software and a 3-CCD colour video camera, multiple images are digitized, combined to form a photo-montage and revisited after each of the three staining protocols. By applying image registration techniques, the spatial distribution of HbO2 saturations is matched to corresponding hypoxic marker intensities in adjacent sections. This permits vascular configuration to be related to oxygen availability and allows the hypoxic marker intensities to be quantitated in situ. (+info)
Effect of chronic hypoxia on alpha-1 adrenoceptor-mediated inositol 1,4,5-trisphosphate signaling in ovine uterine artery. (2/8649)The present study examined the effect of chronic hypoxia on coupling efficiency of alpha-1 adrenoceptors to inositol 1,4,5-trisphosphate (InsP3) signaling in ovine uterine artery. Chronic hypoxia did not change the time course of InsP3 formation, but significantly decreased the potency (pD2: 6.17 +/- 0.09 --> 5.26 +/- 0.12) and the maximal response (220.7 +/- 21.7 --> 147.7 +/- 15.3 pmol/mg protein) of norepinephrine-induced InsP3 synthesis. The coupling efficiency of alpha-1 adrenoceptors to InsP3 synthesis (picomoles InsP3 per femtomoles receptor) was decreased 45% by chronic hypoxia. In addition, simultaneous measurement of norepinephrine-induced contractions and InsP3 synthesis indicated that for a given amount of InsP3 generated, the contractile force of the uterine artery was significantly less in chronically hypoxic than in control tissues (0. 27 +/- 0.01 versus 0.35 +/- 0.02 g tension/pmol InsP3). InsP3 receptors were characterized using radioligand binding techniques. Although the density of InsP3 receptors was not changed by chronic hypoxia (Bmax: 325 +/- 35 --> 378 +/- 18 fmol/mg protein), the dissociation constant (Kd) of InsP3 to its receptors was significantly increased (Kd: 5.20 +/- 0.40 --> 7.81 +/- 0.34 nM). Analysis of InsP3 receptor occupancy-tension development relationship indicated no difference in intrinsic ability of the InsP3-receptor complex in eliciting contractions between the control and hypoxic tissues. Our results suggest that chronic hypoxia attenuates coupling efficiency of alpha-1 adrenoceptors to InsP3 synthesis in the uterine artery. In addition, the tissue contractile sensitivity to InsP3 is reduced, which is mediated predominantly by a decrease in InsP3 binding affinity to InsP3 receptors. (+info)
Nonlinear indicial response of complex nonstationary oscillations as pulmonary hypertension responding to step hypoxia. (3/8649)This paper is devoted to the quantization of the degree of nonlinearity of the relationship between two biological variables when one of the variables is a complex nonstationary oscillatory signal. An example of the situation is the indicial responses of pulmonary blood pressure (P) to step changes of oxygen tension (DeltapO2) in the breathing gas. For a step change of DeltapO2 beginning at time t1, the pulmonary blood pressure is a nonlinear function of time and DeltapO2, which can be written as P(t-t1 | DeltapO2). An effective method does not exist to examine the nonlinear function P(t-t1 | DeltapO2). A systematic approach is proposed here. The definitions of mean trends and oscillations about the means are the keys. With these keys a practical method of calculation is devised. We fit the mean trends of blood pressure with analytic functions of time, whose nonlinearity with respect to the oxygen level is clarified here. The associated oscillations about the mean can be transformed into Hilbert spectrum. An integration of the square of the Hilbert spectrum over frequency yields a measure of oscillatory energy, which is also a function of time, whose mean trends can be expressed by analytic functions. The degree of nonlinearity of the oscillatory energy with respect to the oxygen level also is clarified here. Theoretical extension of the experimental nonlinear indicial functions to arbitrary history of hypoxia is proposed. Application of the results to tissue remodeling and tissue engineering of blood vessels is discussed. (+info)
Depression of peripheral chemosensitivity by a dopaminergic mechanism in patients with obstructive sleep apnoea syndrome. (4/8649)In the present study, respiratory drives to chemical stimuli and peripheral chemosensitivity were evaluated in patients with obstructive sleep apnoea (OSAS). The effects of oral administration of domperidone, a selective dopamine D2-receptor antagonist, were also examined, to study the respiratory effects of endogenous dopamine on peripheral chemoreceptors. Sixteen patients with OSAS and nine normal control subjects were studied. Respiratory responses to hypercapnia and hypoxia were measured using the rebreathing method and isocapnic progressive hypoxia method, respectively. The hypoxic withdrawal test, which measures the decrease in ventilation caused by two breaths of 100% O2 under mild hypercapnic hypoxic conditions (end-tidal oxygen and carbon dioxide tensions approximately 8.0 kPa and 5.3-6.7 kPa, respectively), was used to evaluate peripheral chemosensitivity. In the patients with OSAS, ventilatory responses to hypercapnia and hypoxia were significantly decreased compared with those of control subjects. Hypoxic withdrawal tests showed that peripheral chemosensitivity was significantly lower in patients with OSAS than in normal subjects. Hypercapnic ventilatory response and peripheral chemosensitivity were enhanced by administration of domperidone in the patients with OSAS, although no changes in either of these were observed in the control subjects. The hypoxic ventilatory response and peripheral chemosensitivity in the patients with OSAS were each significantly correlated with severity of hypoxia during sleep. These findings suggest that peripheral chemosensitivity in patients with obstructive sleep apnoea syndrome may be decreased as a result of abnormality in dopaminergic mechanisms and that the reduced chemosensitivity observed in patients with obstructive sleep apnoea syndrome may affect the severity of hypoxia during sleep. (+info)
Evidence of O2 supply-dependent VO2 max in the exercise-trained human quadriceps. (5/8649)Maximal O2 delivery and O2 uptake (VO2) per 100 g of active muscle mass are far greater during knee extensor (KE) than during cycle exercise: 73 and 60 ml. min-1. 100 g-1 (2.4 kg of muscle) (R. S. Richardson, D. R. Knight, D. C. Poole, S. S. Kurdak, M. C. Hogan, B. Grassi, and P. D. Wagner. Am. J. Physiol. 268 (Heart Circ. Physiol. 37): H1453-H1461, 1995) and 28 and 25 ml. min-1. 100 g-1 (7.5 kg of muscle) (D. R. Knight, W. Schaffartzik, H. J. Guy, R. Predilleto, M. C. Hogan, and P. D. Wagner. J. Appl. Physiol. 75: 2586-2593, 1993), respectively. Although this is evidence of muscle O2 supply dependence in itself, it raises the following question: With such high O2 delivery in KE, are the quadriceps still O2 supply dependent at maximal exercise? To answer this question, seven trained subjects performed maximum KE exercise in hypoxia [0.12 inspired O2 fraction (FIO2)], normoxia (0.21 FIO2), and hyperoxia (1.0 FIO2) in a balanced order. The protocol (after warm-up) was a square wave to a previously determined maximum work rate followed by incremental stages to ensure that a true maximum was achieved under each condition. Direct measures of arterial and venous blood O2 concentration in combination with a thermodilution blood flow technique allowed the determination of O2 delivery and muscle VO2. Maximal O2 delivery increased with inspired O2: 1.3 +/- 0.1, 1.6 +/- 0.2, and 1.9 +/- 0.2 l/min at 0.12, 0.21, and 1.0 FIO2, respectively (P < 0.05). Maximal work rate was affected by variations in inspired O2 (-25 and +14% at 0.12 and 1.0 FIO2, respectively, compared with normoxia, P < 0.05) as was maximal VO2 (VO2 max): 1.04 +/- 0.13, 1. 24 +/- 0.16, and 1.45 +/- 0.19 l/min at 0.12, 0.21, and 1.0 FIO2, respectively (P < 0.05). Calculated mean capillary PO2 also varied with FIO2 (28.3 +/- 1.0, 34.8 +/- 2.0, and 40.7 +/- 1.9 Torr at 0.12, 0.21, and 1.0 FIO2, respectively, P < 0.05) and was proportionally related to changes in VO2 max, supporting our previous finding that a decrease in O2 supply will proportionately decrease muscle VO2 max. As even in the isolated quadriceps (where normoxic O2 delivery is the highest recorded in humans) an increase in O2 supply by hyperoxia allows the achievement of a greater VO2 max, we conclude that, in normoxic conditions of isolated KE exercise, KE VO2 max in trained subjects is not limited by mitochondrial metabolic rate but, rather, by O2 supply. (+info)
Mechanisms of hypoxic vasodilatation of isolated rat mesenteric arteries: a comparison with metabolic inhibition. (6/8649)1. Hypoxia (PO2 < 5 mmHg) decreased vessel tone in isolated rat mesenteric arteries precontracted with either high [K+] or the thromboxane analogue U46619. This response was not altered by N-nitro-L-arginine (L-NA) and indomethacin. 2. Simultaneous measurement of pHi and tension showed that the decrease in vessel tone was accompanied by an intracellular acidification. Similar reductions in tone and pHi were observed with the metabolic inhibitors 2,4-dinitrophenol (DNP) and sodium azide. 3. The presence of the lactate transport inhibitor alpha-cyano-4-hydroxy-cinnamic acid (CHC) increased the magnitude of the acidification and resulted in a significantly faster reduction in tone in response to hypoxia. Addition of CHC to normoxic tissues caused both a vasodilatation and a reduction of pHi. 4. A decrease in pHi induced on washout of ammonium chloride (NH4Cl) resulted in an increase in tone. 5. Relaxation to hypoxia or metabolic inhibition was unaffected when the change in pHi was neutralized by addition of the weak base trimethylamine (TMA). 6. It is concluded that severe hypoxia decreases tone in isolated rat mesenteric arteries by a mechanism which is independent of nitric oxide and prostaglandins. Both severe hypoxia and metabolic inhibition reduced pHi, although this does not appear to be contributing to the changes in tone observed. (+info)
Comparison of vascular reactivity in spinal cord and brain. (7/8649)The local tissue PO2 in the brain cortex and in the spinal cord of rats was examined with ultramicroelectrodes. In the spinal cord the PO2 was highest in white matter, intermediate in dorsal horn gray matter, and lowest in the ventral horn gray matter. In the gray matter of the cord, as well as in the brain, the PO2 at a fixed locus was found normally to oscillate. CO2 responses were more brisk in the cord than in the brain while the responses to hypoxia were similar. Therefore, it appears that the physiological regulation of blood flow in the spinal cord is qualitatively similar to that of the brain. (+info)
Estimation of corneal endothelial pump function in long-term contact lens wearers. (8/8649)PURPOSE: To study the effects of long-term contact lens wear on morphologic and physiologic properties of corneal endothelial cells. METHODS: The endothelial permeability to fluorescein and the rate of corneal deswelling from hypoxia-induced edema were measured in 20 long-term (mean, 17+/-9 years; range, 5-33 years) contact lens wearers and 20 age-matched control subjects. From these data, the relative endothelial pump rate in each subject was estimated, based on the pump-leak hypothesis of corneal hydration control. Corneal autofluorescence and the aqueous humor flow rate were determined by fluorescein fluorophotometry. Images of corneal endothelial cells were recorded by using specular microscopy, and morphologic indices (cell density, coefficient of variation of cell area, percentage of hexagonal cells, and skewness) were determined. RESULTS: No statistically significant differences were found between the contact lens and control groups in endothelial permeability, corneal deswelling, relative endothelial pump rate ([mean +/- SD] 1.07+/-0.33 relative pump units versus 1.01+/-0.25 relative pump units; contact lens versus control; P = 0.57), and endothelial cell density. Contact lens wearers had a significantly higher aqueous humor flow rate (3.57+/-1.03 microl/min versus 2.77+/-0.51 microl/min; P = 0.005), coefficient of variation of cell area (0.35+/-0.09 versus 0.28+/-0.04; P = 0.006), and corneal autofluorescence (3.1+/-0.6 ng/ml versus 2.3+/-0.3 ng/ml fluorescein equivalents; P < 0.001) than did non-contact lens wearers. CONCLUSIONS: Despite the known effects of long-term contact lens wear on corneal endothelial morphometry, no effect on endothelial function was found. (+info)
Intermittent hypoxic training protects canine myocardium from infarction<...
TY - JOUR. T1 - Intermittent hypoxic training protects canine myocardium from infarction. AU - Zong, Pu. AU - Setty, Srinath. AU - Sun, Wei. AU - Martinez, Rodolfo. AU - Tune, Johnathan D.. AU - Ehrenburg, Igor V.. AU - Tkatchouk, Elena N.. AU - Mallet, Robert T.. AU - Downey, H. Fred. PY - 2004/9. Y1 - 2004/9. N2 - This investigation examined cardiac protective effects of normobaric intermittent hypoxia training. Six dogs underwent intermittent hypoxic training for 20 consecutive days in a normobaric chamber ventilated intermittently with N2 to reduce fraction of inspired oxygen (FIO2) to 9.5%-10%. Hypoxic periods, initially 5 mins and increasing to 10 mins, were followed by 4-min normoxic periods. This hypoxia-normoxia protocol was repeated, initially 5 times and increasing to 8 times. The dogs showed no discomfort during intermittent hypoxic training. After 20 days of hypoxic training, the resistance of ventricular myocardium to infarction was assessed in an acute experiment. The left ...
Acute intermittent hypoxia exposures enhance arterial oxygen delivery<...
TY - JOUR. T1 - Acute intermittent hypoxia exposures enhance arterial oxygen delivery. AU - Zhang, Peizhen. AU - Downey, H. Fred. AU - Shi, Xiangrong. PY - 2010/9. Y1 - 2010/9. N2 - Physiological adaptations to intermittent hypoxia (IH) conditioning are based on the cumulative effect of repeated IH exposures. The present study sought to test the hypothesis that acute IH exposures would promote arterial O2 delivery and regional tissue oxygenation. Changes in arterial O2 saturation (SaO2, oximeter), forearm muscle and cerebral tissue oxygenations (SmO2 and ScO2, near-infrared spectroscopy) were compared during five repeated hypoxia exposures (10±0.2% O2 for 5-min each) interposed with four-minute inhalation of room air in 11 healthy subjects (24±0.9 y). Baseline, prehypoxia partial pressure of end-tidal O2 (PETO 2, mass spectrometer) and SaO2 (107±2 mmHg and 97.3±0.3%) were decreased (P, 0.05) after the first bout as compared with those during normoxia prior to the second (94±2 mmHg and ...
Intermittent hypoxia-induced changes in tumor-associated macro...
Adiponectin protects rat myocardium against chronic intermittent hypoxia-induced injury via inhibition of endoplasmic reticulum...
TY - JOUR. T1 - Adiponectin protects rat myocardium against chronic intermittent hypoxia-induced injury via inhibition of endoplasmic reticulum stress. AU - Ding, Wenxiao. AU - Zhang, Xiaofeng. AU - Huang, Hanpeng. AU - Ding, Ning. AU - Zhang, Shijiang. AU - Hutchinson, Sean Z.. AU - Zhang, Xilong. PY - 2014/4/9. Y1 - 2014/4/9. N2 - Obstructive sleep apnea syndrome (OSAS) is associated with many cardiovascular disorders such as heart failure, hypertension, atherosclerosis, and arrhythmia and so on. Of the many associated factors, chronic intermittent hypoxia (CIH) in particular is the primary player in OSAS. To assess the effects of CIH on cardiac function secondary to OSAS, we established a model to study the effects of CIH on Wistar rats. Specifically, we examined the possible underlying cellular mechanisms of hypoxic tissue damage and the possible protective role of adiponectin against hypoxic insults. In the first treatment group, rats were exposed to CIH conditions (nadir O2, 5-6%) for 8 ...
Two temporal components within the human pulmonary vascular response to approximately 2 h of isocapnic hypoxia. - Physiology,...
The time course of the pulmonary vascular response to hypoxia in humans has not been fully defined. In this investigation, study A was designed to assess the form of the increase in pulmonary vascular tone at the onset of hypoxia and to determine whether a steady plateau ensues over the following approximately 20 min. Twelve volunteers were exposed twice to 5 min of isocapnic euoxia (end-tidal Po(2) = 100 Torr), 25 min of isocapnic hypoxia (end-tidal Po(2) = 50 Torr), and finally 5 min of isocapnic euoxia. Study B was designed to look for the onset of a slower pulmonary vascular response, and, if possible, to determine a latency for this process. Seven volunteers were exposed to 5 min of isocapnic euoxia, 105 min of isocapnic hypoxia, and finally 10 min of isocapnic euoxia. For both studies, control protocols consisting of isocapnic euoxia were undertaken. Doppler echocardiography was used to measure cardiac output and the maximum tricuspid pressure gradient during systole, and estimates of pulmonary
The Effect of Chronic Intermittent Hypoxia on Breast Cancer Cell Gene Expression and Malignant Properties - Zurich Open...
Breast cancer is the most common cancer in women worldwide and the second most common cancer overall. The most aggressive and most lethal form of breast cancer is inflammatory breast cancer (IBC). The mechanisms underlying the aggressiveness of IBC are still poorly understood. A key feature in the development and progression of breast cancer is the tumor microenvironment that is, amongst others, characterized by a specific composition of the extracellular matrix (ECM) and by the occurrence of tissue hypoxia and oxidative stress. Due to vascular remodeling, leading to structurally and functionally abnormal tumor vessels, tumor cells are exposed to alternating periods of hypoxia and reoxygenation, called chronic intermittent hypoxia (CIH). CIH is a cause of increased reactive oxygen species (ROS) production and has been identified as an important factor in promoting tumor progression and metastasis. However, the molecular mechanisms through which CIH increases the aggressiveness of breast cancer ...
Pseudo-subarachnoid haemorrhage due to chronic hypoxaemia: case report and review of the literature | BMC Neurology | Full Text
The specificity of computed tomography (CT) for subarachnoid haemorrhage (SAH) is very high. However, physicians should be aware of rare false positive findings, also referred to as pseudo-SAH. We present an unusual case in which such a finding was caused by chronic hypoxaemia. A 37-year-old male patient presented with headaches. His CT-scan showed multiple confluent subarachnoid hyperattenuations, which mimicked SAH. However, the headache was chronic and had no features typical for SAH. The patient suffered from severe chronic hypoxaemia due to congenital heart failure. On CT-angiography diffuse intracranial vessel proliferation was found and laboratory results revealed a highly raised level of haematocrit, which had both probably developed as compensatory mechanisms. A combination of these findings explained the subarachnoid hyperdensities. Magnetic resonance imaging (MRI) showed no signs of SAH and visualized hypoxaemia in cerebral veins. A diagnosis of pseudo-SAH was made. The patients symptoms
Frontiers | Intermittent Hypoxia in Childhood: The Harmful Consequences Versus Potential Benefits of Therapeutic Uses |...
Intermittent hypoxia often occurs in early infancy in both preterm and term infants and especially at 36 to 44 weeks postmenstrual age. These episodes of intermittent hypoxia could result from sleep-disordered breathing or may be temporally unrelated to apnea or bradycardia events. There are numerous reports indicating adverse effects of intermittent hypoxia on development, behavior, academic achievement and cognition in children with sleep apnea syndrome. It remains uncertain the exact causative relationship between the neurocognitive and behavioral morbidities and intermittent hypoxia and/or its associated sleep fragmentation. On the other hand, well-controlled and moderate intermittent hypoxia conditioning/training has been used in sick children for treating their various forms of bronchial asthma, allergic dermatoses, autoimmune thyroiditis, cerebral palsy, and obesity. This review article provides an updated and impartial analysis on the currently available evidence in supporting either side of the
Intermittent hypoxia increases arterial blood pressure in humans through a Renin-Angiotensin system-dependent mechanism.
Hyperoxia and moderate hypoxia fail to affect inspiratory muscle fatigue in humans - Fingerprint - UTMB Health Research...
Intermittent vs continuous hypoxia: effects on ventilation and erythropoiesis in humans.
Cardiovascular Consequences of Intermittent Hypoxia in Healthy Subjects - Full Text View - ClinicalTrials.gov
The study is a prospective field evaluation to assess the effects of the chronic Intermittent Hypoxia exposure in 12 healthy humans.. Precisely, the study was designed to :. Set up a new model of Chronic Intermittent Hypoxia (CIH) applied to healthy human. This CIH is mimicking the CIH undergone by patients suffering from Sleep Apnea Syndrome.. Evaluate the cardiovascular effect of CIH. Neuronal and humoral sympathetic control, blood pressure control, vascular resistance.. Evaluate the Sleep quality, the ventilation under exposure and the long terms effect on ventilation control of CIH (central and peripheral chemoreflex).. Investigates the biological aspects of CIH exposure. ...
Effect of acute hypoxia on the hormonal response to exercise | Garvan Institute of Medical Research
The hormonal responses to submaximal exercise under normoxic and hypoxic conditions were studied in eight fit males, aged 22--28 yr, with mean maximal oxygen uptake of 4.4 +/- 0.7 l/min. Studies were performed in a hypobaric chamber, decompressed to a simulated altitude of 4,550 m (PIO2 = 83 Torr). The subjects exercised for 20 min at 750 kpm/min on a cycle ergometer. Venous blood samples were obtained at rest, during exercise and for 60 min after exercise. Plasma glucose, free fatty acids, lactate, cortisol, and serum growth hormone concentrations all increased more during hypoxic exercise than under normoxic conditions. Serum insulin concentration showed a small decrease under normoxic conditions, but decreased by 50% during hypoxic exercise, and was followed by marked rebound when exercise stopped. These changes suggest that energy substrate-hormone interrelationships are altered by hypoxic exercise, resulting in increased fat mobilization and increased gluconeogenesis.
Strength of pulmonary vascular response to regional alveolar hypoxia. - Semantic Scholar
Regional alveolar hypoxia in the lung induces regional pulmonary vasoconstriction which diverts blood flow from the hypoxic area. However, the predominant determinant of the distribution of perfusion in the normal erect lung is gravity so that more perfusion occurs at the base than at the apex. To determine the strength of the regional alveolar hypoxic response in diverting flow with or against the gravity gradient a divided tracheal cannula was placed in anesthetized dogs and unilateral alveolar hypoxia created by venilating one lung with nitrogen while ventilating the other lung with oxygen to preserve normal systemic oxygentation. Scintigrams of the distribution of perfusion obtained with intravenous 13-N and the MGH positron camera revealed a 34 and 32 per cent decrease in perfusion to the hypoxic lung in the supine and erect positions and a 26 per cent decrease in the decubitus position with the hypoxic lung dependent (P equal to 0.94 from supine shift), indicating nearly equal vasoconstriction
Role of Hypoxia-Inducible Factors in Regulating Right Ventricular Function and Remodeling during Chronic Hypoxia-Induced...
Pulmonary hypertension (PH) and right ventricular (RV) hypertrophy frequently develop in patients with hypoxic lung disease. Chronic alveolar hypoxia (CH) promotes sustained pulmonary vasoconstriction and pulmonary artery (PA) remodeling by acting on lung cells, resulting in the development of PH. RV hypertrophy develops in response to PH, but arterial hypoxemia in CH may influence that response by activating Hypoxia-Inducible Factor-1α (HIF-1α) and/or HIF-2α in cardiomyocytes. Indeed, other studies show that attenuation of PH in CH fails to prevent RV remodeling, suggesting that PH-independent factors regulate RV hypertrophy. Therefore, we examined the role of HIFs in RV remodeling in CH-induced PH. We deleted HIF-1α and/or HIF-2α in hearts of adult mice that were then housed under normoxia or CH (10% O2) for 4 weeks. RNA-seq analysis of the RV revealed that HIF-1α and HIF-2α regulate the transcription of largely distinct gene sets during CH. RV systolic pressure (RVSP) increased and RV ...
Age-dependent vulnerability to ischemia-reperfusion injury of cyanotic myocardium in a chronic hypoxic rat model<...
TY - JOUR. T1 - Age-dependent vulnerability to ischemia-reperfusion injury of cyanotic myocardium in a chronic hypoxic rat model. AU - Fujita, Yasufumi. AU - Ishino, Kozo. AU - Nakanishi, Koji. AU - Fujii, Yasuhiro. AU - Kawada, Masaaki. AU - Sano, Shunji. PY - 2009/11. Y1 - 2009/11. N2 - This study evaluated the effects of chronic hypoxia from birth on the resistance of rat hearts to global ischemia, with special emphasis on the duration of hypoxia. Male Wistar rats were housed from birth for 4 weeks or 8 weeks either in a hypoxic environment (FiO2 = 0.12) or in ambient air (8 animals for each group). Isolated rat hearts were perfused for 40 min with oxygenated Krebs-Henseleit buffer, subjected to 20 min global no-flow ischemia at 37°C, and then underwent 40 min of reperfusion. A non-elastic balloon was inserted into the left ventricle and inflated until the pre-ischemic LVEDP rose to 8mmHg. Cardiac function was measured before and after ischemia. The post-ischemic percent recovery of LVDP in ...
Sub-lethal effects of hypoxia on harpacticoid copepod reproduction
Areas of hypoxia are found in coastal areas worldwide, and have become increasingly widespread. These areas vary in their duration and dissolved oxygen concentration from occasional diurnal hypoxia, as found in Corpus Christi Bay, Texas, seasonal hypoxia as in the northern Gulf of Mexico, to continuous hypoxia as found in oceanic oxygen minimum zones. The effects of exposure to low dissolved oxygen (DO) depend on the duration of exposure, the DO concentration and an organisms tolerance to hypoxic conditions. Most studies have focused on lethal effects of hypoxia by comparing the abundance of benthic organisms and the species composition of benthic communities between hypoxic and normoxic areas. Sub-lethal effects of such as changes in reproduction may occur at less severe hypoxic conditions (by definition), but may still have effects at the population level. The goal of this study is to examine the sub-lethal reproductive effects of low DO on harpacticoid copepods. The life-history traits and ...
HIF-1α Mediates Tumor Hypoxia to Confer a Perpetual Mesenchymal Phenotype for Malignant Progression | Science Signaling
Although tumor progression involves genetic and epigenetic alterations to normal cellular biology, the underlying mechanisms of these changes remain obscure. Numerous studies have shown that hypoxia-inducible factor 1α (HIF-1α) is overexpressed in many human cancers and up-regulates a host of hypoxia-responsive genes for cancer growth and survival. We recently identified an alternative mechanism of HIF-1α function that induces genetic alterations by suppressing DNA repair. Here, we show that long-term hypoxia, which mimics the tumor microenvironment, drives a perpetual epithelial-mesenchymal transition (EMT) through up-regulation of the zinc finger E-box binding homeobox protein ZEB2, whereas short-term hypoxia induces a reversible EMT that requires the transcription factor Twist1. Moreover, we show that the perpetual EMT driven by chronic hypoxia depends on HIF-1α induction of genetic alterations rather than its canonical transcriptional activator function. These mesenchymal tumor cells not ...
Injury of ascending reticular activating system associated with delayed post-hypoxic leukoencephalopathy: a case report | BMC...
In the current study, three portions of the ARAS (the dorsal lower ARAS, ventral lower ARAS and upper ARAS) in a patient with impaired consciousness following DPHL caused by CO poisoning were evaluated using DTT. We found that these three portions of the ARAS were injured in both hemispheres: the upper ARAS - decreased neural connectivity to both frontal cortexes, basal forebrains, basal ganglia and thalami, the dorsal lower ARAS - non-reconstruction in the right side and narrowing in the left side and the ventral lower ARAS -non-reconstruction in both sides. We believe that the impaired consciousness in this patient was ascribed to the injury of the three portions of the ARAS.. Many studies have reported abnormality of the white matter including basal ganglia (caudate nucleus, putamen, and globus pallidus) in patients with DPHL using various neuroimaging tools including conventional MRI [5-13]. Neurological manifestations were observed as follows: 1) cognitive impairments - confusion, ...
As solid tumors grow, regions in the tumor become hypoxic because of increased metabolism, heterogeneous and abnormal vasculature delivering oxygen within the tumor, and greater size. In order for the tumor to continue to grow, it depends on survival mechanisms to overcome this hypoxic state, including up-regulation in glycolysis, invasion and metastasis, and angiogenesis, or the growth of new blood vessels. The hypoxia-inducible factor (HIF) transcription factor complex is a major mediator of the cells response to a hypoxic state and a tumors survival mechanism under hypoxia. The complex is composed of the hypoxia-dependent HIF-1α subunit and a constitutively expressed HIF-1α subunit, and it requires the co-activator protein p300 to function. In the presence of oxygen, HIF-1α is rapidly degraded. Under hypoxia, HIF-1α forms a complex with HIF-1α and p300 in the nucleus to up-regulate transcription of pro-survival and angiogenic genes. Targeting this transcription factor complex in tumors ...
Hypoxia increases the proliferation of hCMPCs. hCMPCs w | Open-i
Identification of cyclooxygenase-2 as a major actor of the transcriptomic adaptation of endothelial and tumor cells to cyclic...
fr] OBJECTIF: hypoxie cycliques dans les tumeurs proviennent de lhétérogénéité dans le flux de RBC et influence non seulement les cellules tumorales mais également des cellules endothéliales qui tapissent les vaisseaux sanguins tumoraux. Whether pO(2) fluctuations, particularly transient reoxygenation periods, alter the well-known hypoxia-inducible factor (HIF)-dependent gene program is largely unknown. Que Po (2) les fluctuations, en particulier réoxygénation des périodes transitoires, de modifier lhypoxie bien connue-inducible factor (HIF)-programme des gènes dépendant est largement inconnue. EXPERIMENTAL DESIGN: We compared the transcriptomic profiles of endothelial and tumor cells exposed to cyclic hypoxia versus continuous hypoxia to uncover a possible differential effect on angiogenesis and metastases. EXPERIMENTAL DESIGN: Nous avons comparé les profils transcriptomiques de endothéliales et les cellules tumorales exposées à lhypoxie cyclique par rapport à lhypoxie ...
Hypoxia increases transcript levels of enzymes involved | Open-i
Impact of the phosphatidylinositide 3-kinase signaling pathway on the cardioprotection induced by intermittent hypoxia |...
BACKGROUND: Exposure to intermittent hypoxia (IH) may enhance cardiac function and protects heart against ischemia-reperfusion (I/R) injury. To elucidate the underlying mechanisms, we developed a cardioprotective IH model that was characterized at hemodynamic, biochemical and molecular levels. METHODS: Mice were exposed to 4 daily IH cycles (each composed of 2-min at 6-8% O2 followed by 3-min reoxygenation for 5 times) for 14 days, with normoxic mice as controls. Mice were then anesthetized and subdivided in various subgroups for analysis of contractility (pressure-volume loop), morphology, biochemistry or resistance to I/R (30-min occlusion of the left anterior descending coronary artery (LAD) followed by reperfusion and measurement of the area at risk and infarct size). In some mice, the phosphatidylinositide 3-kinase (PI3K) inhibitor wortmannin was administered (24 µg/kg ip) 15 min before LAD. RESULTS: We found that IH did not induce myocardial hypertrophy; rather both contractility and ...
Hypoxia due to shunts in pig lung treated with DDFPe
Abigail Hielscher, PhD
Hypoxia And Hypoxemia: Causes, Symptoms, Prevention & Treatment
Intermittent hypoxia increases exercise tolerance in elderly men with and without coronary artery disease | Meta
Intermittent hypoxia has been suggested to increase exercise tolerance by enhancing stress resistance and improving oxygen delivery. Because the improvement of exercise tolerance reduces mortality in the elderly with and without coronary artery disease intermittent hypoxia might be a valuable preventive and therapeutic tool. However, controlled studies are lacking. Sixteen males (50-70 years, 8 with and 8 without prior myocardial infarction) were randomly assigned in a double-blind fashion to receive 15 sessions of passive intermittent hypoxia (hypoxia group) or normoxia (control group) within 3 weeks. For the hypoxia group each session consisted of three to five hypoxic (14-10% oxygen) periods (3-5 min) with 3-min normoxic intervals. Controls inhaled only normoxic air in the same way. Exercise tests were performed before and after the 3-week breathing program. After 3 weeks of intermittent hypoxia peak oxygen consumption had increased compared to normoxic conditions (+ 6.2% vs.-3%, p , 0.001). ...
Domiciliary liquid oxygen versus concentrator treatment in chronic hypoxaemia: a cost-utility analysis | European Respiratory...
Whether long-term oxygen therapy (LTOT) improves quality of life in chronic hypoxaemia has been questioned. LTOT with an oxygen concentrator (C/C) and gas cylinders for ambulation is considered cumbersome compared to mobile liquid oxygen equipment (L). The hypothesis for this study was that LTOT with liquid oxygen treatment (L) improves patients health-related quality of life, but that it is also more expensive compared to concentrator (C/C) treatment. A prospective, randomized multicentre trial comparing C/C with L for LTOT was conducted during a six-month period. Fifty-one patients (29 on L and 22 on C/C) with chronic hypoxaemia, regularly active outside the home, participated in the study initially. Costs for oxygen were obtained from the pharmacies. Patient diaries and telephone contacts with members of the healthcare sector were used to estimate costs. Health-related quality of life was measured by the Sickness Impact Profile (SIP) and the EuroQol, instruments at the start and after 6 ...
Perinatal hypoxia enhances cyclic adenosine monophosphate-mediated BKCa channel activation in adult murine pulmonary artery. -...
Exposure to perinatal hypoxia results in alteration of the adult pulmonary circulation, which is linked among others to alterations in K(+) channels in pulmonary artery (PA) smooth muscle cells. In particular, large conductance Ca(2+)-activated K(+) (BK(Ca)) channels protein expression and activity were increased in adult PA from mice born in hypoxia compared with controls. We evaluated long-term effects of perinatal hypoxia on the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway-mediated activation of BK(Ca) channels, using isoproterenol, forskolin, and dibutyryl-cAMP. Whole-cell outward current was higher in pulmonary artery smooth muscle cells from mice born in hypoxia compared with controls. Spontaneous transient outward currents, representative of BK(Ca) activity, were present in a greater proportion in pulmonary artery smooth muscle cells of mice born in hypoxia than in controls. Agonists induced a greater relaxation in PA of mice born in hypoxia compared with controls, and BK
"Pulmonary vasoconstrictor reactivity following intermittent hypoxia" by Jessica Snow
Sleep apnea (SA) affects as many as 20% of the adult population in the United States. It elicits intermittent hypoxia (IH) and causes pulmonary hypertension (PH), however the mechanisms of this PH have not been well studied. IH has been shown to cause polycythemia, pulmonary vascular remodeling and increases in vasoconstrictor reactivity. CO2 supplementation may be protective in the development of PH, therefore we assessed effects of IH with and without CO2 supplementation on indices of PH and pulmonary vasoconstrictor reactivity. IH with CO2 supplementation resulted in eucapnic IH (E-IH) and the lack of polycythemia or vascular remodeling. However, E-IH caused significant right ventricular hypertrophy and increased pulmonary vasoconstrictor reactivity, which was mediated by vascular smooth muscle (VSM) Ca2+ sensitization. We, therefore, sought to determine the mechanism of this enhanced vasoconstrictor reactivity by assessing vasoconstriction and VSM Ca2+ responses to the endothelium-derived
Long-term histological outcome after post-hypoxic treatment with 100% or 40% oxygen in a model of perinatal hypoxic-ischemic...
TY - JOUR. T1 - Long-term histological outcome after post-hypoxic treatment with 100% or 40% oxygen in a model of perinatal hypoxic-ischemic brain injury. AU - Grafe, Marjorie. AU - Woodworth, K. Nina. AU - Noppens, Kristin. AU - Perez-Polo, J. Regino. PY - 2008/2. Y1 - 2008/2. N2 - Hypoxic newborns have traditionally been given supplemental oxygen, and until recently, guidelines for neonatal resuscitation recommended that 100% oxygen be used. Exposure to 100% oxygen after hypoxic injury, however, may exacerbate oxidative stress. The current study evaluated the effect of exposure to 100, 40 or 21% oxygen after neonatal hypoxic-ischemic injury on the severity of brain injury after long-term survival. The severity of histological brain injury was not different in animals exposed to 100% oxygen versus room air. Male animals treated with 40% oxygen post-hypoxia had the lowest mean total histology scores, but this was not statistically significant due to the large variation in injury within each ...
Human ventilatory response to CO2 after 8 h of isocapnic or poikilocapnic hypoxia. - Oxford Neuroscience
During ventilatory acclimatization to hypoxia (VAH), the relationship between ventilation (VE) and end-tidal PCO2 (PETCO2) changes. This study was designed to determine 1) whether these changes can be seen early in VAH and 2) if these changes are present, whether the responses differ between isocapnic and poikilocapnic exposures. Ten healthy volunteers were studied by using three 8-h exposures: 1) isocapnic hypoxia (IH), end-tidal PO2 (PETO2) = 55 Torr and PETCO2 held at the subjects normal prehypoxic value; 2) poikilocapnic hypoxia (PH), PETO2 = 55 Torr; and 3) control (C), air breathing. The VE-PETCO2 relationship was determined in hyperoxia (PETO2 = 200 Torr) before and after the exposures. We found a significant increase in the slopes of VE-PETCO2 relationship after both hypoxic exposures compared with control (IH vs. C, P | 0.01; PH vs. C, P | 0.001; analysis of covariance with pairwise comparisons). This increase was not significantly different between protocols IH and PH. No significant changes
Moderating Effect of Low Doses of Ethanol on Reoxygenation Injury in the Anoxic Myocardium<...
TY - JOUR. T1 - Moderating Effect of Low Doses of Ethanol on Reoxygenation Injury in the Anoxic Myocardium. AU - Kobayashi, H.. AU - Ashraf, Muhammad. AU - Rahamathulla, P. M.. AU - Minami, M.. PY - 1987/1/1. Y1 - 1987/1/1. N2 - We have investigated the action of ethanol on the reoxygenation injury in isolated rat hearts. Perfusion of the anoxic Krebs-Henseleit medium for 40 minutes followed by 30 minutes of perfusion with aerobic medium produced considerable myocardial cell injury. Incorporation of ethanol (21.7 mMol), in both anoxic and aerobic perfusion media resulted in a marked reduction of cell injury and inhibition of creative kinase. Contraction band necrosis was reduced to 0.25 as compared to 1.14 per field in the non-treated hearts. The tissue Ca++ was decreased to 8.2 as compared to 12.12 µmoll/g/dry weight in the non-treated hearts and tissue ATP was increased by 50% in the treated tissue (9.33 µmoll/g/dry wt) as compared to the non-treated anoxic tissue (S.S µmol). Thus, ethanol ...
Silencing of STIM1 attenuates hypoxia-induced PASMCs proliferation via inhibition of the SOC/Ca2+/NFAT pathway | Respiratory...
Continuous or intermittent hypobaric hypoxia can lead to long-term contraction of the pulmonary artery and structural changes in the pulmonary vascular wall known as hypoxic pulmonary vessel remodelling (HPVR) . HPVR is characterised by thickening of small pulmonary artery wall and muscularizing of pulmonary arteriole, which can result in sustained high pulmonary artery pressure and right ventricular hypertrophy . It has become clear that pulmonary vascular smooth muscle cells (PASMCs) are closely related to the development of pulmonary hypertension, which are regulated by intracellular Ca2+ concentrations and calmodulin (CaM) . The intracellular Ca2+ concentration has also been suggested to regulate gene expression and cellular proliferation [2, 6, 22-25]. Intracellular calcium levels in PASMCs are mainly regulated by extracellular calcium influx and the release of intracellular calcium stores. Chelation of extracellular calcium in human PASMCs can significantly inhibit serum or ...
Frontiers | Acute Normobaric Hypoxia Increases Post-exercise Lipid Oxidation in Healthy Males | Physiology
The primary objective of the current study was to determine the effect of moderate normobaric hypoxia exposure during constant load cycling on post-exercise energy metabolism recorded in normoxia. Indirect calorimetry was used to examine whole body substrate oxidation before, during, 40-60 min post, and 22 h after performing 60 min of cycling exercise at two different fractions of inspired oxygen (FIO2): (i) FIO2 = 0.2091 (normoxia) and (ii) FIO2 = 0.15 (hypoxia). Seven active healthy male participants (26 ± 4 years of age) completed both experimental trials in randomized order with a 7-day washout period to avoid carryover effects between conditions. Resting energy expenditure was initially elevated following cycling exercise in normoxia and hypoxia (Δ 0.14 ± 0.05, kcal min−1, p = 0.037; Δ 0.19 ± 0.03 kcal min−1, p −1, p = 0.019) and tended to suppress carbohydrate oxidation (Δ −55 ± 26 mg min−1, p = 0.076) 40-60 min post-exercise. This shift in substrate oxidation persisted the next
Effect of hematocrit on systemic O2 transport in hypoxic and normoxic exercise in rats<...
TY - JOUR. T1 - Effect of hematocrit on systemic O2 transport in hypoxic and normoxic exercise in rats. AU - Gonzalez, N C. AU - Erwig, Lars Peter. AU - Painter, C F. AU - Clancy, R L. AU - Wagner, P D. PY - 1994/9/1. Y1 - 1994/9/1. N2 - The effect of hematocrit (Hct) on O2 transport in hypoxic [inspired PO2 (PIO2) approximately 70 Torr] and normoxic (PIO2 approximately 145 Torr) exercise was studied in rats acclimatized to 3 wk of PIO2 at approximately 70 Torr (A rats) and in nonacclimatized littermates (NA rats). Isovolumic exchange transfusion of plasma or red blood cells was used to lower Hct in A rats from approximately 60 to 45% and to raise Hct of NA rats from 45 to 60%: Controls were A and NA rats exchange transfused with whole blood at constant Hct. Lowering Hct of A rats lowered the arterial O2 concentration (CaO2) and the arterial-mixed venous O2 difference and increased the maximal cardiac output (Qmax) without changes in maximal O2 uptake (VO2 max) or in the product of Qmax x CaO2, ...
Serotonin-dependent respiratory plasticity | Respiratory Research | Full Text
Serotonin initiates neuroplasticity in a number of invertebrate and vertebrate experimental models. The first report of serotonin-dependent plasticity in respiratory motor control was a long-lasting facilitation of phrenic activity following episodic stimulation of chemoafferent neurons , a phenomenon now known as long-term facilitation (LTF). Recent progress has contributed considerably towards an understanding of the mechanisms and manifestations of this potentially important model of respiratory plasticity. In this presentation, recent progress in understanding the mechanism of LTF will be reviewed. In all studies, we exposed awake or anesthetized Sprague Dawley rats to episodic hypoxia as an experimental model of LTF. Both awake and anesthetized rats express LTF following episodic hypoxia. Intermittent, but not continuous hypoxia elicits LTF, indicating remarkable pattern sensitivity in its underlying mechanism. Both episodic chemoafferent activation by stimulation of the carotid sinus ...
An insert-based enzymatic cell culture system to rapidly and reversibly induce hypoxia: investigations of hypoxia-induced cell...
Tissue hypoxia is frequently found under various pathophysiological conditions, such as circulatory failure, myocardial infarction and cerebral ischemia (Garin et al., 2005; Li and Jackson, 2002; McCord, 1985; Michiels, 2004). Owing to the high incidence and clinical relevance of tissue hypoxia and ischemia-reperfusion injury, an understanding of the hypoxia-associated cellular and molecular mechanisms is essential for the development of new and effective strategies to reduce ischemia-reperfusion- and tissue-hypoxia-mediated cell damage.. An elegant and straightforward method for the investigation of hypoxia-associated mechanisms is the use of cell culture systems. So far, different in vitro models (e.g. hypoxic chambers, chemical or enzymatic generation of hypoxia) have been employed to induce hypoxic conditions in cultures of cell lines and primary cells and to evaluate the effects as well as underlying mechanisms of in vitro hypoxia. Unfortunately, all of the currently described models have ...
Hypoxicator - Wikipedia
A hypoxicator is a medical device intended to provide a stimulus for the adaptation of an individuals cardiovascular system by means of breathing reduced oxygen hypoxic air and triggering mechanisms of compensation. The aim of intermittent hypoxic training or hypoxic therapy conducted with such a device is to obtain benefits in physical performance and wellbeing through improved oxygen metabolism. There are several commercial systems available, the most popular being Hypoxico, Inc., who pioneered normobaric hypoxic altitude training systems. Most of these systems have not been cleared for medical applications by the FDA and are used by athletes for altitude training. Advanced hypoxicators have a built-in pulse oximeter used to monitor and in some cases control the temporary reduction of arterial oxygen saturation that results in physiological responses evident at both systemic and cellular levels even after only a few minutes of hypoxia. Hypoxic Training Index (HTi) can be used to measure the ...
Histone Deacetylation Inhibition in Pulmonary HypertensionClinical Perspective | Circulation
This study demonstrates for the first time changes in the expression of HDAC proteins, specifically increased HDAC1 (class I) and HDAC5 (class II), in human IPAH lung. These data were replicated in lungs and RV from rats with hypoxia-induced pulmonary hypertension. The lack of change in HDAC expression in the kidneys from these animals links the observed changes in HDAC expression to the pathological vascular remodeling of pulmonary hypertension rather than the hypoxic stimulus per se. Immunohistochemical assessment of human IPAH and chronic hypoxic rat lungs confirmed increased nuclear expression of HDAC1 and cytoplasmic expression of HDAC5 in remodeled vessels. These vessels also express the proliferative marker Ki67, supporting a link between aberrant epigenetic changes and dysregulated cell proliferation. Consistent with a functional role for HDACs in pulmonary hypertension, long-term administration of VPA, a HDAC class I inhibitor, not only prevented hypoxia-induced pulmonary hypertension ...
Right ventricular hypertrophy and polycythaemia in rats after intermittent exposure to hypoxia | Clinical Science
1. Six groups of 20 male adult rats were maintained in an environmental chamber, each group for a period of 28 days. One group breathed air throughout its experimental period, and a second group breathed a normobaric atmosphere of 12% oxygen. The other four groups were exposed to this hypoxic atmosphere for only a proportion of each 24 h cycle: 2, 4 and 12 h daily, and eight periods of 30 min daily.. 2. After 28 days, measurement was made, in each rat, of right ventricule (RV) weight and of red cell mass (RCM) by using 51Cr-labelled rat erythrocytes.. 3. In the normoxic control group, RV weight corrected for log body weight in grams was 63.2 ± 1 mg/log body wt. and RCM was 2.02 ± 0.05 ml/100 g body wt. This was significantly less than in the group hypoxic for only 2 h each day for 28 days: RV weight 66.6 ± 0.8 mg/log body wt. (P , 0.05) and RCM 2.27 ± 0.05 ml/100g body wt. (P , 0.05). Greater increases compared with control were observed in all the other hypoxic groups. There was no ...
ASSA13-10-16 The Role of Endoplasmic Reticulum Stress in The Injury Induced by Bim of Hypoxic Cardiomyocytes | Heart
Results Green fluorescence was observed in the cells transfected of negative control siRNA group though the fluorescence microscope. Compared with the blank control group, The MTT assay determined that the survival rate of H9C2 was decreased (p , 0.05) after the injured by hypoxia. And the results of flow cytometry showed that hypoxia increased cell apoptosis rate (P , 0.01) and the concentration of calcium (p , 0.01), while the transfection of Bim-siRNA reduced the effects caused by hypoxia (P , 0.05 or P , 0.01). Compared with the hypoxia group, the transfection of Bim-siRNA increased the cell survival rate, decreased cell apoptosis rate and the concentration of calcium (p , 0.01 or p , 0.05). While there was no significant difference among Hypoxia Group, Hypoxia + Negative Control siRNA Group and Hypoxia + Mock control Group (p , 0.05). The results of Western blotting showed that the transfection of Bim-siRNA reduced the expression of Bim obviously (p , 0.01); meanwhile, reduced the ...
"Effect of Captopril Treatment on Chronic Hypoxia Induced Pulmonary Vas" by Robert C. Molthen, Amy E. Heinrich et al.
Pulmonary vascular remodeling is one of the typical responses to chronic alveolar hypoxia in the rat model of pulmonary hypertension (PH). Neither the etiology nor the structural and functional consequences of this remodeling are well understood. It is known that chronic treatment with ACE inhibitors results in a reduction of lung perfusion pressures and vascular changes in hypoxic PH, but the effect of treatment with ACE inhibitors on arterial tree morphology and mechanical properties of the artery walls in the intact lung have not been examined. In addition to using standard hemodynamic analysis, we approach this problem with x-ray micro-CT imaging and measure the distensibility of pulmonary arteries (approximate range of 50 - 2000 um diameter) in rat lungs. We examine consequences of chronic hypoxic exposure (10% O2) with and without Captopril treatment in FH, SD and BN rats. The FH rat strain is known to possess a genetic susceptibility to PH whereas the BN strain is resistant to PH. An example of
Fujita, Yasufumi - Author List - OKAYAMA UNIVERSITY SCIENTIFIC ACHIEVEMENT REPOSITORY
p,This study evaluated the effects of chronic hypoxia from birth on the resistance of rat hearts to global ischemia, with special emphasis on the duration of hypoxia. Male Wistar rats were housed from birth for 4 weeks or 8 weeks either in a hypoxic environment (FiO20.12) or in ambient air (8 animals for each group). Isolated rat hearts were perfused for 40 min with oxygenated Krebs-Henseleit buffer, subjected to 20 min global no-flow ischemia at 37, and then underwent 40 min of reperfusion. A non-elastic balloon was inserted into the left ventricle and inflated until the pre-ischemic LVEDP rose to 8mmHg. Cardiac function was measured before and after ischemia. The post-ischemic percent recovery of LVDP in hypoxic hearts was worse than in normoxic hearts (4 weeks:55+/-7 vs. 96+/-3%, p0.01;8 weeks:40+/-5 vs. 92+/-4%, p0.01), and was worst in the 8-week-hypoxic hearts. Similarly, the percent recovery of dP/dt in the hypoxic hearts was lower than in the normoxic hearts (4 weeks:51+/-5 vs. 96+/-7%, ...
Aerosol Gene Transfer With Inducible Nitric Oxide Synthase Reduces Hypoxic Pulmonary Hypertension and Pulmonary Vascular...
NO/cGMP signal transduction plays an important role in the modulation of pulmonary vascular tone and structure in response to acute and chronic changes in oxygen tension. In this study, single aerosol delivery of adenoviral vectors expressing NOS2 and NOS3 gene in rat lungs resulted in immunoreactive NOS2 and NOS3 localized in bronchial and alveolar epithelial cells. NOS gene transfer increased pulmonary cGMP levels and elevated exhaled NO levels for at least 1 week. Significantly higher NO production was observed in NOS2-aerosolized rats than in NOS3- and control virus-infected rats. The acute hypoxia-induced vasoconstrictor response was significantly and equally reduced in both NOS2- and NOS3-infected rats. In contrast, in rats breathing Fio2 0.10 for 1 week, a single administration of AdNOS2 significantly reduced the rise in PAP, the increase in fractional right ventricular weight, and the degree of pulmonary vascular remodeling. In contrast, single administration of AdRR5 or AdNOS3 did not ...
Fgfr1 Is Required for Cortical Regeneration and Repair after Perinatal Hypoxia | Journal of Neuroscience
We report that chronic sublethal hypoxia in newborn mice produces an initial 30% deficit in cortical neurons, two-thirds of which are excitatory neurons expressing the transcription factor Tbr1. Over the ensuing 4 weeks in normoxic conditions, the deficit in neuron number recovers, such that neither NeuN+, Tbr1+ nor SMI-32+ neurons are decreased in the cortex of hypoxic-reared mice at P48. However, there is an enduring loss in PV+ and CR+ inhibitory interneurons in the hypoxic mice, which creates an imbalance between excitatory and inhibitory neurons in the hypoxic cortex. Disrupting the Fgfr1 gene in GFAP+ cells of the developing dorsal telencephalon (including cortical radial glial cells and all their progeny) does not alter the initial loss of cortical neurons but precludes the recovery of NeuN+, Tbr1+ and SMI-32+ neuron number in the cerebral cortex. Hypoxic exposure increases cell proliferation and the generation of Tbr1+ cortical excitatory neurons and that of OB granular neurons, ...
Respiratory control during air-breathing exercise in humans following an 8 h exposure to hypoxia. - Oxford Neuroscience
Hypoxic exposure lasting a few hours results in an elevation of ventilation and a lowering of end-tidal P(CO2) (P(ET(CO2))) that persists on return to breathing air. We sought to determine whether this increment in ventilation is fixed (hypothesis 1), or whether it increases in proportion to the rise in metabolic rate associated with exercise (hypothesis 2). Ten subjects were studied on two separate days. On 1 day, subjects were exposed to 8h of isocapnic hypoxia (end-tidal P(O2) 55 Torr) and on the other day to 8 h of euoxia as a control. Before and 30 min after each exposure, subjects undertook an incremental exercise test. The best fit of a model for the variation in P(ET(CO2)) with metabolic rate gave a residual squared error that was approximately 20-fold less for hypothesis 2 than for hypothesis 1 (p|0.005, F-ratio test). We conclude that the alterations in respiratory control induced during early ventilatory acclimatization to hypoxia better reflect those associated with hypothesis 2 rather than
Inhibition of Rho-Kinase Attenuates Hypoxia-Induced Angiogenesis in the Pulmonary Circulation | Circulation Research
It has been generally thought that PH predominantly resulted from hypoxia-induced structural changes in the pulmonary vasculature, which produced a fixed increase in resistance. These structural changes included remodeling of the arteriolar walls leading to encroachment into the vascular lumen, and loss of blood vessels, suggesting that interventions, which successfully ameliorated PH, would act by preventing or reversing such structural changes. The results of the present study cast doubt on this paradigm by demonstrating that chronic hypoxia did not cause a structurally based reduction of pulmonary vascular lumen diameter, nor did it cause a loss of pulmonary vessels. Moreover, we report that chronic inhibition of ROCK abrogated the development of hypoxic PH, not by preventing structural encroachment into the vascular lumen, but by inhibiting sustained pulmonary vasoconstriction. Importantly, we also found hypoxia-induced capillary angiogenesis in the adult lung that was dependent on the ...
Studies of Iron Uptake by Duodenal Brush Boeder Membrane Vesicles Prepared Prom Normal and Hypoxic Mice | Clinical Science |...
Intravenous endothelin-1 and ventilatory sensitivity to hypoxia in humans. - Physiology, Anatomy and Genetics
The effects of intravenous endothelin-1 (ET-1) on the ventilatory response to hypoxia were studied in healthy humans. Nine volunteers were each exposed twice to 4 hr eucapnic hypoxia. They received a continuous infusion of ET-1 during the ET-1 protocol and an infusion of saline during the control protocol. Plasma ET-1 levels and an index of ventilation were measured regularly. Hypoxia caused a rise in plasma ET-1 in the control protocol. Hypoxia also caused the index of ventilation to increase in both protocols, and this increase was greater in the ET-1 protocol than in the control protocol. These results are consistent with the hypothesis that ET-1 plays a role in controlling the ventilatory response to hypoxia in man.
Cerebral ischemia /hypoxia - RightDiagnosis.com
Assessment of tumour hypoxia for prediction of response to therapy and cancer prognosis. - Department of Oncology
Tumour cells exploit both genetic and adaptive means to survive and proliferate in hypoxic microenvironments, resulting in the outgrowth of more aggressive tumour cell clones. Direct measurements of tumour oxygenation, and surrogate markers of the hypoxic response in tumours (for instance, hypoxia inducible factor-1alpha, carbonic anhydrase 9 and glucose transporter-1) are well-established prognostic markers in solid cancers. However, individual markers do not fully capture the complex, dynamic and heterogeneous hypoxic response in cancer. To overcome this, expression profiling has been employed to identify hypoxia signatures in cohorts or models of human cancer. Several of these hypoxia signatures have demonstrated prognostic significance in independent cancer datasets. Nevertheless, individual hypoxia markers have been shown to predict the benefit from hypoxia-modifying or anti-angiogenic therapies. This review aims to discuss the clinical impact of translational work on hypoxia markers and to explore
Abstract 289: High Density Lipoproteins Augment Hypoxia-Induced Angiogenesis via Regulation of Post-translational Modification...
Results Pre-incubation with rHDL inhibited the hypoxia-induced increases in PHD2 and PHD3 levels (32% and 45% respectively, p,0.05) while Siah1 and Siah2 mRNA levels were increased (58% and 88% respectively, p,0.05) with rHDL pre-incubation. Following siRNA knockdown of Siah1 and Siah2, HDL lost its ability to induce the expression of HIF-1α (11% reduction, p,0.05) and VEGF (18% reduction, p,0.05). Augmentation of tubulogenesis by HDL was attenuated in Siah siRNA-transfected cells (55% in siSiah1; 40% in siSiah2, p,0.05). Siah knockdown also abrogated HDL inhibition of hypoxia-mediated induction of PHD2 and PHD3 (p,0.05). PI3K and Akt are upstream regulators of HIF-1α/VEGF and also regulate Siahs. Specific inhibition of the PI3K/Akt pathway revealed that it plays a key role in HDL-induced elevations in Siah1 and Siah2 (37% and 20% reduction respectively, p,0.05) as well as HIF-1α and VEGF (65% and 15% reduction respectively, p,0.05). ...
HKU Scholars Hub: Chronic intermittent hypoxia aggravates oxidative stress, inflammation and apoptosis in non-alcoholic fatty...
Brazilian Honey Protects Against Hypoxia
Honey treatment was able to completely block mortality and locomotor phenotypes. In addition, honey was able to reverse ROS production and hypoxia-induced changes in mitochondrial complex I and II activity. Hypoxia also induced an up-regulation in mRNA expression of Sima (HIF-1), NFκβ, NRF2, HOX, AKT-1, InR, dILP2, dILP5 and HSP27. Honey treatment was not able to modulate changes in the tested genes, indicating that its protective effects involve additional mechanisms other than transcriptional activity of hypoxia-driven adaptive responses in flies ...
Hypoxia triggers a proangiogenic pathway involving cancer cell...
Essential Role of Phospholipase C-g1 in Hypoxia-Induced Pulmonary Vasoconstriction and Hypertension | Open Access Journals
Rapidly growing tumors and tumor metastases are exposed to ongoing hypoxic conditions in the tissue microenvironment. Hypoxia, in turn, has a profound influence on tumor pathophysiology. The survival of the tumor and its aggressiveness depend on its ability to respond quickly to hypoxia cues. Cells undergo a variety of biological responses when placed under hypoxic conditions, including activation of signaling pathways that regulate proliferation, angiogenesis, and death (1-3). Cancer cells have adapted these pathways, allowing tumors to survive and even grow under hypoxic conditions (2). Although tissue hypoxia is a well-documented phenomenon, our understanding of the response of tumor cells to hypoxia is far from being complete. The response to hypoxia may be divided into two mechanisms: the first one sensing the level of oxygen and the second one activating the hypoxia-induced genes, some of which contribute to tumor angiogenesis. A large body of evidence accumulated with regard to the role ...
Nephron Power: Consult Rounds: High Uric Acid
Rat and human studies have shown that uric acid levels in hypoxia are much higher than normoxia and hyperoxia. There is a correlation that hypoxia results in greater purine catabolism and leading to increased production of uric acid. Hence we often see lactate levels correlating well with uric acid levels in sepsis. ...
Summary: Altered Coronary Arterial Reactivity Following Pharmacological Perinatal Interventions
The Barker hypothesis proposes that the risk of ischaemic heart disease may be increased in later life by perinatal events that programme permanent alterations to the bodys structure and metabolism. Perinatal modification of arterial compliance and function could initiate and amplify this risk of disease in later life. The aim of this study was to determine whether short-term nitric oxide synthase (NOS) inhibition and transient hypoxia in the perinatal period could initiate changes in vasomotility demonstrable in later life. Dams were given Ng-nitro-L-arginine methyl ester (n = 5) in drinking water or were kept in a normobaric hypoxic chamber (FiO2 10 %) for one week pre- and one week post-partum. Male offspring were sacrificed at 10 weeks and results compared with the male offspring of control dams (n = 7). Coronary artery reactivity, to both constrictors and dilators, was studied using the wire myograph and isolated blood perfused heart preparations. Perinatal inhibition of NOS increased the ...
The principal findings of this study include increased neuronal susceptibility to ASH in animals undergoing chronic exposures to intermittent hypoxia during sleep, mimicking the highly prevalent disorder of sleep apnea. Furthermore, we now show that this increased susceptibility is mediated, at least in part, by chronic IH-induced decreases in the neuronal expression of MCT2, such that alternative sources of energy to neurons during and after ASH cannot be effectively delivered. Together, these results present opportunities to further understand the mechanism underlying the dysregulation of MCT2 in the context of chronic IH and the development of effective strategies aiming at promoting MCT2 expression in patients with sleep apnea who may be at risk for cerebrovascular ischemic events (Minoguchi et al., 2007).. The conceptual framework of a monocarboxylate-dependent energy source alternative to neuronal function and survival has been the subject of substantial debate over the past 2 decades. ...
KAKEN - Research Projects | Molecular physiological studies of in vivo hypoxia niche: formation, sensing and adaptation ...
A DOSE OF 5,000 KM.H OF SEVERE HYPOXIA (AT > 5,000 M ALTITUDE) IS PROBABLY REQUIRED TO INDUCE SKELETAL MUSCLE WASTING IN...
Potentiation of the Ventilatory Response to Inhaled CO2 Following Acute Exposure to Hypoxia | Clinical Science | Portland Press
What Is Cell Hypoxia? (with pictures)
Anoxia | pathology | Britannica.com
Anoxia: …contrast, lack of oxygen (anoxia) may result in a coma that lasts for several weeks and is often fatal. Stroke, a rupture or blockage of vessels supplying blood to the brain, can cause sudden loss of consciousness in some patients, while comas caused by metabolic abnormalities or cerebral tumours…
Animals may have more than one means of surviving hypoxia
This manuscript shows that the DDT neurons of the zebrafish express dopamine. The authors follow on to show that DDT synaptic development and behaviors mediated by these neurons can be adversely affected by hypoxic exposure. The experiments seem to be well performed with appropriate controls used in general. However, the conclusions drawn are not fully supported by the experimental outcomes. These issues are detailed below along with minor issues in the text and scientific descriptions that will help with the ability of non-specialists to decipher the study.. Major changes:. 1. Line 293 - the authors show that a dopaminergic antagonist cause motor impairments and say that they are similar to those observed upon hypoxic exposure. This suggests to the reader that these two perturbations are linked. However, they could have completely independent effects. The authors should perform the D4 antagonist experiment in the context of hypoxia and examine whether the effect is additive or not. This would ...
Dizziness | DailyStrength
Natural cure for Anoxia and alternative treatments
Anoxia technique, applying and explaining for a animal friendly culling
Hypoxemia Global Clinical Trials Review, H2, 2017 : ReportsnReports
Permian-Triassic extinction event
Anoxia. See also: Anoxic event. Evidence for widespread ocean anoxia (severe deficiency of oxygen) and euxinia (presence ... Once anoxia became established, it would have been sustained by a positive feedback loop because deep water anoxia tends to ... The persistence of anoxia through the Early Triassic may explain the slow recovery of marine life after the extinction. Models ... Rather than a sudden decline in sea level, intermittent periods of ocean-bottom hyperoxia and anoxia (high-oxygen and low- or ...
Bernard Raymond Fink
Mechanism of anoxic depolarization in the brain
Another anoxia-tolerant animal that is commonly used as a model to study anoxia in the mammalian brain is the crucian carp, ... Even though glycolysis is stimulated early in anoxia in both the crucian carp and C. picta, the crucian carp is able to stay ... Selective vulnerability is the term used to describe how some parts of the brain are more sensitive to anoxia than others, and ... Anoxia-prone cells in the brain include the hippocampal pyramidal cells of CA1, cerebellar purkinje cells, pyramidal ...
Argon anoxia - Similar to cryofumigation, but using dry argon gas to exclude oxygen. This process may cost more than carbon ... Nitrogen anoxia - Similar to cryofumigation, but using dry nitrogen gas to exclude oxygen This process may cost more than ... "Insect Mortality under Anoxia". Keepsafe. Keepsafe Microclimate Systems. Retrieved 2015-05-20. Daniel, Vinod; et al. (25 ... asphyxiating the insects Carbon dioxide anoxia - Similar to cryofumigation, but using compressed dry carbon dioxide gas to ...
Anoxia - Simple English Wikipedia, the free encyclopedia
Glossary of underwater diving terminology
This is because anoxia slows the degradation of organic matter, allowing for greater burial in the sediments. Other evidence ... This caused a temporary state of total anoxia in the fjord, and resulted in dramatic fish mortality. This fjord is marked by a ... The degree of pyritization and the δ34S were both high, supporting the presence of anoxia and sulfide, as well as the depletion ... Anoxia and sulfidic conditions often occur together. In anoxic conditions anaerobic, sulfate reducing bacteria convert sulfate ...
Carbon dioxide in Earth's atmosphere
Kenneth B. Storey
Anoxia is further influenced by biochemical oxygen demand (BOD), which is the amount oxygen used by marine organisms in the ... This property leads to daily anoxic cycles on small geographic scales and seasonal cycles of anoxia on the larger scale. Thus, ... Sarmiento, J. L.; Herbert, T. D.; Toggweiler, J. R. (1988). "Causes of anoxia in the world ocean". Global Biogeochemical Cycles ... H3PO4 Anoxia is quite common in muddy ocean bottoms where there are both high amounts of organic matter and the low levels ...
Richard B. Frankel
However, anoxia was also rife during the Hirnantian (late Ordovician) ice age. Oceanic anoxic events have been recognized ... Page, A. (2007). "Deglacial anoxia in a long-lived Early Palaeozoic Icehouse." (PDF). In Budd, G.E.; Streng, M.; Daley, A.C.; ... Oceanic anoxic events or anoxic events (anoxia conditions) refer to intervals in the Earth's past where portions of oceans ... The boundary between the Ordovician and Silurian periods is marked by repetitive periods of anoxia, interspersed with normal, ...
Late Devonian extinction
The brims are thought to have served a respiratory purpose, and the increasing anoxia of waters led to an increase in their ... David P. G. Bond; Paul B. Wignalla (2008). "The role of sea-level change and marine anoxia in the Frasnian-Famennian (Late ... Evidence exists of widespread anoxia in oceanic bottom waters; the rate of carbon burial shot up, and benthic organisms were ... The extinction events were accompanied by widespread oceanic anoxia; that is, a lack of oxygen, prohibiting decay and allowing ...
Hypothermia therapy for neonatal encephalopathy
CARIACO Ocean Time Series Program
Permian-Triassic extinction event
Once anoxia became established, it would have been sustained by a positive feedback loop because deep water anoxia tends to ... Perhaps anoxia provides another aspect of what delayed the recovery. During the early Triassic (4 to 6 million years after the ... The persistence of anoxia through the Early Triassic may explain the slow recovery of marine life after the extinction. Models ... Rather than a sudden decline in sea level, intermittent periods of ocean-bottom hyperoxia and anoxia (high-oxygen and low- or ...
Evolution of insects
En Hospitales Nisa somos especialistas en el tratamiento de enfermedades cerebrales como la anoxia. Informacion, Causas y ... ISCHEMIC Anoxia/Hipoxia. Caused by an insufficient supply of oxygen to the brain due to a drop in cerebral blood flow or ... Anoxia ANAEMIC. Caused by an insufficient oxygen supply to the brain because of a drop or irregularity in the oxygen-binding ... Anoxia ANÓXICA. Caused by an insufficient supply of oxygen in the environment. A famous example of this aetiology is altitude ...
Anoxia - Wikipedia
The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia ... Anoxia (beetle), a genus of scarab beetles Oxygen saturation, a relative measure of the oxygen dissolved or carried in a medium ... when the body or a region of the body is deprived of adequate oxygen supply Cerebral anoxia, when the brain is completely ...
Anoxia (beetle) - Wikipedia
Anoxia affinis Anoxia africana Anoxia arenbergeri Anoxia asiatica Anoxia australis Anoxia baraudi Anoxia caphtor Anoxia ... Anoxia pasiphae Anoxia pilosa Anoxia rattoi Anoxia reisseri Anoxia rotroui Anoxia scutellaris Anoxia smyrnensis Anoxia tristis ... Anoxia cingulata Anoxia cretica Anoxia cypria Anoxia derelicta Anoxia desbrochersi Anoxia emarginata Anoxia hirta Anoxia ... Anoxia kocheri Anoxia kraatzi Anoxia laevimacula Anoxia lodosi Anoxia luteipilosa Anoxia maculiventris Anoxia makrisi Anoxia ...
Anoxia | pathology | Britannica.com
... anoxia) may result in a coma that lasts for several weeks and is often fatal. Stroke, a rupture or blockage of vessels ... with lack of oxygen (anoxia). Fetal anoxia may occur from inadequate oxygenation of the mother, low maternal blood pressure, or ... contrast, lack of oxygen (anoxia) may result in a coma that lasts for several weeks and is often fatal. Stroke, a rupture or ... result from insufficient oxygen (anoxia) during a difficult and prolonged delivery or from the condition known as kernicterus, ...
Anoxia: Symptoms, types, and treatment
Anoxia occurs when a persons body or brain stops getting oxygen. Learn more about the causes, symptoms, and types in this ... Some of the different types of anoxia are:. Anemic anoxia. Anemic anoxia takes place where there is not enough hemoglobin in a ... Stagnant anoxia. Stagnant anoxia happens when a persons blood does not reach the brain or other parts of the body that require ... Toxic anoxia. Toxic anoxia stops the blood from carrying oxygen around the body effectively. It can occur after a person ...
Anoxia: Symptoms, Causes, Treatment, and More
Anoxia is usually a result of hypoxia. Heres what you need to know. ... Anoxia happens when your body or brain completely loses its oxygen supply. ... What is anoxia?. Anoxia happens when your body or brain completely loses its oxygen supply. Anoxia is usually a result of ... How is anoxia diagnosed?. In order to find out if any symptoms youre having are related to hypoxia or anoxia, your doctor may ...
Anoxia niceaensis - Wikispecies
anoxia tolerance | Journal of Experimental Biology
Effects of anoxia on ATP, water, ion and pH balance in an insect (Locusta migratoria) Mathias V. Ravn, Jacob B. Campbell, Lucie ... Effects of prolonged anoxia on electrical activity of the heart in crucian carp (Carassius carassius) Elisa Tikkanen, Jaakko ... Taurine activates glycine and GABAA receptor currents in anoxia-tolerant painted turtle pyramidal neurons Ashley R. Miles, ... Anoxia-mediated calcium release through the mitochondrial permeability transition pore silences NMDA receptor currents in ...
Anoxia israelitica Petrovitz, 1971
Anoxia pauliani Dewailly, 1945
Anoxia - Intense Killings: CD, Album, Ltd For Sale | Discogs
Anoxia - Simple English Wikipedia, the free encyclopedia
HELP! ANOXIA - REHABILITATION FOR AMNESIA & MOTORIC PROBLEMS
... Hans Christian Eidenert hce at bahnhof.se Tue Jun 20 05:39:12 EST ... Anoxia with posttraumatic amnesia Hello there, This is a serious attempt to find more information and consultation from various ... The neuropsychologist that I spoke to today told me that in his experience patients with anoxia either regain their motoric ...
Long-Term History of Chesapeake Bay Anoxia | Science
Effect of anoxia on starch breakdown in rice and wheat seeds. - PubMed - NCBI
Effect of anoxia on starch breakdown in rice and wheat seeds.. Perata P1, Pozueta-Romero J, Akazawa T, Yamaguchi J. ... Wheat seeds were shown to germinate even under anoxia if fed glucose or sucrose exogenously. The overall results indicate that ... The results showed that rice, a species highly tolerant to anoxia, can readily break down starch under anaerobiosis concomitant ... in rice under anoxia, whereas the enzyme is not produced in wheat seeds. We found that rice seeds possess a set of enzymes ...
Search of: 'Anoxia' | 'Hypnotics and Sedatives' - Results on Map - ClinicalTrials.gov
Hints: Click on a [map] link to show a map of that region. Click on a [studies] link to search within your current results for studies in that region. Use the back button to return to this list and try another region. Studies with no locations are not included in the counts or on the map. Studies with multiple locations are included in each region containing locations ...
Death in Jurassic Park: global warming and ocean anoxia
anoxia [27,37,40-41], or to global warming [32,42].. Thus it seems a reasonable point to report upon. I agree that most ... But was anoxia the sole cause on a global scale? That, the authors say, remains equivocal: although records of anoxic events ... As I understand the issue that has been raised about ocean anoxia causing widespread extinction on Earth it is not that all the ... Death in Jurassic Park: global warming and ocean anoxia. Posted on 15 March 2013 by John Mason. New research links greenhouse ...
Oceanic Anoxia and the End Permian Mass Extinction | Science
Data on rocks from Spitsbergen and the equatorial sections of Italy and Slovenia indicate that the worlds oceans became anoxic at both low and high paleolatitudes in the Late Permian. Such conditions may have been responsible for the mass extinction at this time. This event affected a wide range of shelf depths and extended into shallow water well above the storm wave base.. ...
Anoxia | definition of anoxia by Medical dictionary
... anoxia explanation free. What is anoxia? Meaning of anoxia medical term. What does anoxia mean? ... Looking for online definition of anoxia in the Medical Dictionary? ... Related to anoxia: acidosis, cerebral palsy, necrosis, Arcoxia, Cerebral anoxia. Anoxia. Definition. Anoxia is a condition ... Kinds of anoxia include anemic anoxia and stagnant anoxia. See also hypoxemia, hypoxia. anoxic, adj. ...
GSA Bulletin: Rock avalanches, ancient weather, astronomical clocks, anoxia, and volcanism | EurekAlert! Science News
In anoxia, why can't humans be more like western painted turtles? | EurekAlert! Science News
... anoxia) of minutes can quickly cause human death. But the western painted turtle can survive anoxia for months without apparent ... In anoxia, why cant humans be more like western painted turtles? The right answer could yield better anesthetics, as well as ... "Key to surviving anoxia is the shutting off of energy-utilizing cellular activities, such as the synthesis of proteins and ... Unlike anoxia-sensitive mammals, this doesnt occur in the western painted turtles brain. *Paper presentation: "NMDA receptor ...
Forever Young: Mechanisms of Natural Anoxia Tolerance and Potential Links to Longevity
The physiological and biochemical mechanisms that underlie anoxia tolerance in turtles include profound metabolic rate ... In the present review we discuss the recent advances made in understanding the molecular nature of anoxia tolerance in turtles ... Many of the mechanisms involved in natural anoxia tolerance, such as hypometabolism or the induction of various protective ... The physiological and biochemical mechanisms that underlie anoxia tolerance in turtles include profound metabolic rate ...
L A N D : Anoxia - LP - IMPORTANT RECORDS - Forced Exposure
Anoxia may well be in a time outside of time. On "Anoxia," cello harmonics swing their head and screech like prancing komodo ... "Anoxia"; Clive Bell: shakuhachi on "Drop City," "Equinox," and "Anoxia"; Leo Abrahams: processed guitars on "Neutra," " ... The second L A N D album, Anoxia, sees Daniel Lea return alone with an outing that marks a shift from the industrial-inflected ... "Anoxia" means "total absence of oxygen," and in Leas hands the term heralds aural environments that are full of the dreams of ...
Role of cholinergic systems in the recovery period after acute hypobaric anoxia | SpringerLink
Alybaev, A.M., Bobkov, Y.G. & Losev, A.S. Role of cholinergic systems in the recovery period after acute hypobaric anoxia. Bull ... Role of cholinergic systems in the recovery period after acute hypobaric anoxia. *A. M. Alybaev, ... V. A. Berezovskii (ed.), Anoxia and Individual Differences in Reactivity [in Russian], Kiev (1978). ...
Glyceraldehyde-3-Phosphate Dehydrogenase Mediates Anoxia Response and Survival in Caenorhabditis elegans | Genetics
1 day of anoxia (20°), 5 days of anoxia (20°), 1 day of normoxia (28°), or 1 day of anoxia (28°). Animals exposed to anoxia ... anoxia survival phenotypes:. The long-term anoxia and high-temperature anoxia survival phenotypes of daf-2(e1370) animals were ... time-lapse microscopy is used to assay animal motility in anoxia. Time 0 is when the anoxia sensor in the anoxia bag indicates ... animals have an enhanced anoxia-survival phenotype in that they survive long-term anoxia and high-temperature anoxia, do not ...
Introducing a new associated blog: From Data to Anoxia | Haffenreffer Museum of Anthropology
Anoxia definition | Psychology Glossary | alleydog.com
Psychology definition for Anoxia in normal everyday language, edited by psychologists, professors and leading students. Help us ... Anoxia. Anoxia occurs when oxygen is absent or depleted and unable to properly reach organs or tissue. Anoxia has been shown to ... Anoxia typically refers to complete oxygen deprivation while partial deprivation is called hypoxia (although occasionally these ... terms are used interchangeably). Anoxia can be caused by a variety of situations like asthma, medical conditions that affect ...
Cardiovascular regulation during anoxia in the turtle: an in vivo study
... Physiol Zool. Jan-Feb 1998;71(1):1-14. doi: 10.1086/ ... In contrast, injection of atropine during anoxia resulted in an increase in the heart rate and systemic blood flow, suggesting ... Injections of epinephrine during anoxia had no effect on heart rate, pulmonary blood flow, or systemic blood flow. ... Cardiovascular variables were continuously monitored during normoxia, 2 h of anoxia, and during recovery at normoxia. In ...
Frontiers | Editorial: Eukaryotic Microbes Store Nitrate for "Breathing" in Anoxia | Microbiology
Anoxia inside the aggregates enables nitrate-storing and aggregate-forming diatoms, such as Skeletonema marinoi, to perform ... Anoxia triggers denitrification activity that is apparently mediated by bacterial endobionts since it can be inhibited by ... Citation: Kamp A and Stief P (2017) Editorial: Eukaryotic Microbes Store Nitrate for "Breathing" in Anoxia. Front. Microbiol. 8 ... Editorial: Eukaryotic Microbes Store Nitrate for "Breathing" in Anoxia. Anja Kamp1 and Peter Stief2* ...
Frontiers | Small Non-coding RNA Expression and Vertebrate Anoxia Tolerance | Genetics
... were exposed to anoxia and recovery, and sncRNAs were sequenced from the brain (one of the most anoxia-sensitive tissues) prior ... were exposed to anoxia and recovery, and sncRNAs were sequenced from the brain (one of the most anoxia-sensitive tissues) prior ... were identified in the other anoxia tolerant vertebrates here but did not display a similarly robust response to anoxia. ... Here, we conduct a comparative study on the presence and expression of small ncRNAs in the most anoxia-tolerant representatives ...
HypoxiaOxygenTreatmentTimeBrainAnoxicResponse to anoxiaToleranceReoxygenation InjuryPainted turtleDays of anoxiaEffects of anoxiaHypoxia and anoxiaCerebralPathwaysStagnantSymptoms of anoxia may notSurvivalActivity duringPeriod of anoxiaShow that anoxiaCauses of anoxiaAnemicEpileptiform activityLack of oxygenGenusTrachemysOcean anoxiaOceanic AnoxiaExtreme form of hypoxiaCardiomyocytesSpeciesBenthicApoptosis2017SurviveGenesGlutamate releaseTissueTurtlesNMDALactateInhibitoryAdaptationsTissuesCardiovascularTemperatureSeedlingsFetalTotal absence of oxygenPeriodsEnzymeOccursAMNESIAToxicOxygen supplyInsufficient oxygen
- This type of brain injury (encephalopathy) is caused by partial (hypoxia) or total (anoxia) deprivation of the brain's oxygen supply for longer than the compensatory mechanisms designed to prevent neuronal death can cope. (neurorhb.com)
- Ischemic anoxia/hypoxia is most commonly caused by the following problems in newborns: problems with blood flow between the mother and foetus, placental abruption, umbilical cord compression, or uterine rupture. (neurorhb.com)
- Anoxic anoxia can happen when there is not enough oxygen available to ensure the body functions properly. (medicalnewstoday.com)
- Anoxic anoxia happens when there's not enough oxygen available to your body. (healthline.com)
- One form of anoxic anoxia can happen when you're at high altitudes. (healthline.com)
- Exerting yourself when you're at high altitudes can make the effects of anoxic anoxia worse. (healthline.com)
- Anoxic anoxia can also be caused by anything that keeps your lungs from working properly and limiting the body's oxygen. (healthline.com)
- Taurine increases naturally in anoxic painted turtle brain and can activate both GABA and glycine receptors, which probably contributes to the mechanism of anoxia tolerance. (biologists.org)
- This receptor/channel is strongly associated with anoxic damage in the mammalian brain by permitting a very large flow of calcium ions into the cell during anoxia. (eurekalert.org)
- In contrast, injection of atropine during anoxia resulted in an increase in the heart rate and systemic blood flow, suggesting that the anoxic cardiac response is partially mediated through cholinergic mechanisms. (nih.gov)
- These findings support an overall stabilization of the small ncRNA transcriptome during exposure to anoxic insults, but also suggest that multiple small ncRNA expression pathways may support anoxia tolerance, as no conserved small ncRNA response was identified among the anoxia-tolerant vertebrates studied. (frontiersin.org)
- In contrast, anoxia per se results in limited changes to cardiac AP shape or ion current densities in turtle and crucian carp, suggesting that anoxic modifications of cardiac electrophysiology to reduce ATP demand are not extensive. (biomedsearch.com)
- The amount of apoptotic cells did not increase significantly after 7 days of anoxia (at 9 °C). However, when the anoxic fish were given 1 day of reoxygenation at normal oxygen levels, a 170 % increase in the number of apoptotic cells was detected. (uio.no)
- Genes induced (D) or repressed (E) by anoxia were plotted on the basis of their fold change following the anoxic treatment (horizontal axis) and the heat + anoxia treatment (vertical axis). (plantphysiol.org)
- Our observations of ongoing calcification under anoxic conditions mean that geochemical proxy data obtained from benthic foraminifera in settings experiencing intermittent anoxia have to be reconsidered. (biogeosciences.net)
- The depths of onset of hypoxia and anoxia were then interpolated between sampling stations producing two surfaces representing the depth at which hypoxic and anoxic conditions respectively are found. (smhi.se)
- Turtle brain is remarkably tolerant of anoxia, maintaining a pre-anoxic [Ca2+]i while cerebral adenosine levels increase 12-fold. (biologists.org)
- Threshold potentials did decrease significantly following 60 min of anoxic or adenosine perfusion (control -33.3+/-1.9 mV, anoxia -28.4+/-1.5 mV, adenosine -23.4+/-2.8 mV). (biologists.org)
- Belkin DA (1968a) Anaerobic brain function: effects of stagnant and anoxic anoxia on persistence of breathing in reptiles. (springer.com)
- The crucian carp (Carassius carassius) is one of very few vertebrates that can tolerate several months completely without oxygen (anoxia), a trait that enables this fish to survive under the ice in small ponds that become anoxic during the winter. (uio.no)
- These results provide insight into the effects of Suc on the anoxic transcriptome and provide a list of candidate genes that enhance anoxia tolerance of Suc-treated seedlings. (plantphysiol.org)
- In contrast, differentially expressed genes are mostly unique to each species, suggesting that each species may have evolved distinct small ncRNA expression patterns in response to anoxia. (frontiersin.org)
- Mitochondria-derived small ncRNAs (mitosRNAs) which have a robust response to anoxia in A. limnaeus embryos, were identified in the other anoxia tolerant vertebrates here but did not display a similarly robust response to anoxia. (frontiersin.org)
- Nilsson, G.E. and P.L. Lutz, Release of inhibitory neurotransmitters in response to anoxia in turtle brain. (springer.com)
- Results: ChREBP was anoxia-responsive in kidney and liver, with transcript levels increasing by 1.2-1.8 fold in response to anoxia and protein levels increasing by 1.8-1.9 fold. (chalmers.se)
- Conclusions: The results suggest that activation of ChREBP in response to anoxia might be a crucial factor for anoxia survival in turtle liver by contributing to elevated glycolytic flux in the initial phases of oxygen limitation. (chalmers.se)
- General significance: This study provides the first demonstration of activation of ChREBP in response to anoxia in a natural model of anoxia tolerance, further improving our understanding of the molecular nature of anoxia tolerance. (chalmers.se)
- However, basic biochemical pathways are common to almost all species, certainly among reptiles (turtles), fish, birds and mammals," Buck said, adding: "Therefore, the basic signals and pathways that permit anoxia-tolerance in the turtle must also be present in mammals. (eurekalert.org)
- In studying the natural mechanisms of anoxia tolerance, Buck's lab focused on a particular ion channel, the N-methyl-D-aspartate (NMDA) receptor. (eurekalert.org)
- This result indicates that this channel plays a key role in the natural anoxia-tolerance of the turtle and opens a new research direction in this area. (eurekalert.org)
- The physiological and biochemical mechanisms that underlie anoxia tolerance in turtles include profound metabolic rate depression, post-translational modification of proteins, strong antioxidant defenses, activation of specific stress-responsive transcription factors, and enhanced expression of cyto-protective proteins. (hindawi.com)
- Many of the mechanisms involved in natural anoxia tolerance, such as hypometabolism or the induction of various protective proteins/pathways, have been shown to play important roles in mammalian oxygen-related diseases and improved understanding of how cells survive without oxygen could aid in the understanding and treatment of various pathological conditions that involve hypoxia or oxidative stress. (hindawi.com)
- In the present review we discuss the recent advances made in understanding the molecular nature of anoxia tolerance in turtles and the potential links between this tolerance and longevity. (hindawi.com)
- Extreme anoxia tolerance requires a metabolic depression whose modulation could involve small non-coding RNAs (small ncRNAs), which are specific, rapid, and reversible regulators of gene expression. (frontiersin.org)
- A previous study of small ncRNA expression in embryos of the annual killifish Austrofundulus limnaeus , the most anoxia-tolerant vertebrate known, revealed a specific expression pattern of small ncRNAs that could play important roles in anoxia tolerance. (frontiersin.org)
- Here, we conduct a comparative study on the presence and expression of small ncRNAs in the most anoxia-tolerant representatives of several major vertebrate lineages, to investigate the evolution of and mechanisms supporting extreme anoxia tolerance. (frontiersin.org)
- This may reflect divergent strategies to achieve the same endpoint: anoxia tolerance. (frontiersin.org)
- Only a handful of vertebrates from diverse lineages have evolved tolerance of extended periods of time without oxygen (anoxia) ( Bickler and Buck, 2007 ). (frontiersin.org)
- Comparing how these few anoxia-tolerant vertebrate species survive in habitats that are regularly depleted of oxygen provides insight into the evolution of anoxia tolerance, and may uncover unique cellular and genetic mechanisms supporting this rare ability. (frontiersin.org)
- In the present review, we summarize the current and limited understanding of the cellular mechanisms underlying this cardiac anoxia tolerance. (biomedsearch.com)
- Additionally, as knowledge of cellular physiology in non-mammalian vertebrates is still in its infancy, we briefly discuss the cellular defense mechanisms towards the acidosis that accompanies anoxia as well as mammalian cardiac models of hypoxia/ischemia tolerance. (biomedsearch.com)
- By examining if fundamental cellular mechanisms have been conserved during the evolution of anoxia tolerance we hope to have provided a framework for the design of future experiments investigating cardiac cellular mechanisms of anoxia survival. (biomedsearch.com)
- This points at an hitherto unrecognized aspect of anoxia tolerance in crucian carp: the need to possess effective mechanisms to repair a damaged brain after anoxia / reoxygenation events. (uio.no)
- While in this mass larvae may experience periods of no oxygen (anoxia), little oxygen (hypoxia), or normal oxygen (normoxia), but the tolerance of blow fly larvae to severe hypoxic conditions is not known. (unl.edu)
- I tested the anoxia tolerance of four species of calliphorids ( Calliphora vicina, Cochliomyia macellaria, Lucilia sericata, and Phormia regina ), using third stage larvae across five temperatures. (unl.edu)
- B, H 2 O 2 production under anoxia and heat (38°C). C, Effects of 5 m m H 2 O 2 on anoxia tolerance. (plantphysiol.org)
- Role of HsfA2 in anoxia tolerance. (plantphysiol.org)
- Belkin DA (1963) Anoxia: tolerance in reptiles. (springer.com)
- Bickler PE (1992) Cerebral anoxia tolerance in turtles: regulation of intracellular calcium and pH. (springer.com)
- Exogenous sucrose (Suc) greatly enhances anoxia tolerance of Arabidopsis ( Arabidopsis thaliana ) seedlings. (plantphysiol.org)
- Interestingly, a short heat treatment enhanced anoxia tolerance, suggesting that heat shock proteins may play a role in survival to low oxygen. (plantphysiol.org)
- Oeiras, tolerance of anoxia decreased as the temperature increased, although rice was more tolerant than pea at a given temperature. (st-andrews.ac.uk)
- All rice varieties were more tolerant of anoxia at 25°C than was pea at 20°C, but differences between the tolerance limits of the rice varieties were apparent. (st-andrews.ac.uk)
- Ethanol accumulated around the roots of all seedlings during anoxia, but there was no correlation between the quantity of ethanol produced and the different tolerance limits of the seedlings. (st-andrews.ac.uk)
- The results revealed that berberine treatment downregulated the serum expression of inflammatory factors, including interleukin (IL)‑6, tumor necrosis factor‑α, IL‑10 and IL‑17A in mice with anoxia‑reoxygenation injury. (spandidos-publications.com)
- Berberine treatment also decreased myocardial cell apoptosis following anoxia‑reoxygenation injury via regulating the expression of apoptosis‑associated genes. (spandidos-publications.com)
- The body weight, blood lipid levels, blood pressure and heart rate were markedly improved in mice with anoxia‑reoxygenation injury following berberine treatment compared with untreated mice. (spandidos-publications.com)
- The expression of p38 mitogen‑activated protein kinase (MAPK) and nuclear factor (NF)‑κB expression was downregulated in myocardial cells from in mice with anoxia‑reoxygenation injury following berberine treatment compared with untreated mice. (spandidos-publications.com)
- These results suggest that berberine may be an effective treatment for anoxia‑reoxygenation injury. (spandidos-publications.com)
- At present, anoxia-reoxygenation injury of the heart represents a serious threat to human health ( 9 ). (spandidos-publications.com)
- As such, developing our understanding of the potential signaling mechanism of anoxia-reoxygenation injury is essential for the prevention and treatment of cardiovascular disease. (spandidos-publications.com)
- Anoxia-reoxygenation injury-associated coronary heart disease has high morbidity and mortality ( 10 ). (spandidos-publications.com)
- Inflammation is one of the most common pathogeneses observed and serves an important role in the progression of anoxia-reoxygenation injury ( 11 , 12 ). (spandidos-publications.com)
- However, the potential molecular signaling pathways mediated by berberine anoxia-reoxygenation injury remain to be elucidated. (spandidos-publications.com)
- However a Western painted turtle can survive anoxia for months without apparent tissue damage. (eurekalert.org)
- Paper presentation: "NMDA receptor regulation by mitochondrial KATP channels and adenosine receptors in cortical neurons of the anoxia-tolerant western painted turtle," 12:30 p.m.-3 p.m. Sunday April 3, Physiology 381.3/board #A558. (eurekalert.org)
- In this article, we look at the most common causes and symptoms of anoxia, as well as how the effects of anoxia are treated. (medicalnewstoday.com)
- C, MapMan representation of the effects of anoxia, heat, and heat + anoxia on genes annotated as "heat responsive" or "anoxia responsive. (plantphysiol.org)
- Effects of anoxia, heat, and combined heat + anoxia treatments on the expression of selected anaerobic genes. (plantphysiol.org)
- B, Heat map showing the effects of anoxia, heat, and combined heat + anoxia treatments on the expression of putative targets of HsfA2 . (plantphysiol.org)
- T.M. Bosley, P.L. Woodhams, R.D. Gordon and R. Balozs, Effects of anoxia on the stimulated release of amino acid neurotransmitters in the cerebellum in vitro . (springer.com)
- Addition of exogenous Suc mitigated the effects of anoxia on auxin responsive genes that are repressed under oxygen deprivation. (plantphysiol.org)
- Estimates of the extent of hypoxia and anoxia in Autumn 2007. (europa.eu)
- Enter your email address where to send 'Estimates of the extent of hypoxia and anoxia in Autumn 2007. (europa.eu)
- The volume and area of hypoxia and anoxia have been calculated and the results have then been transformed to maps and diagrams to visualize the annual autumn oxygen situation during the analysed period. (smhi.se)
- The mRNA levels of these subunits were measured with quantitative PCR and were generally well maintained in hypoxia and anoxia in heart and brain. (uio.no)
- This type of lack of oxygen in the brain - cerebral anoxia is sometimes cited as a possible cause of the near death experience . (paranormality.com)
- San Diego (April 3, 2005) - For a human, mere minutes without oxygen (called anoxia) resulting from cardiac arrest, cerebral stroke or being trapped under water can lead to profound tissue damage and even death. (eurekalert.org)
- Generally, the term cerebral anoxia is used to describe both unless a distinction between the two terms becomes necessary, such as in extreme cases. (smithjonessolicitors.co.uk)
- One possibility is that anoxia initiates apoptotic pathways in the brain without leading to actual cell death until oxygen is restored. (uio.no)
- Besides the expected induction of genes encoding enzymes involved in Suc metabolism and alcoholic fermentation, a large number of genes not related to these pathways were affected by anoxia. (plantphysiol.org)
- Stagnant anoxia happens when a person's blood does not reach the brain or other parts of the body that require blood to function correctly. (medicalnewstoday.com)
- Cardiovascular problems, such as a stroke or heart failure , are often the cause of stagnant anoxia. (medicalnewstoday.com)
- Stagnant anoxia is also known as hypoxicischemic injury. (healthline.com)
- Cardiovascular events are the most common cause of stagnant anoxia. (healthline.com)
- Stagnant anoxia occurs when there is interference with the blood flow, although the blood and its oxygen-carrying abilities are normal. (thefreedictionary.com)
- A common cause of general stagnant anoxia is heart disease or interference with the return of blood flow through the veins. (thefreedictionary.com)
- Examples of local stagnant anoxia include exposure to cold, diseases that restrict circulation to the extremities, and ergot poisoning . (thefreedictionary.com)
- What increases my risk for stagnant anoxia? (sharecare.com)
- Heart disease, asthma, and emphysema all increase your risk for stagnant anoxia. (sharecare.com)
- There is a risk of stagnant anoxia with any surgical procedure that requires general anesthesia. (sharecare.com)
- Although stagnant anoxia is not common, it can occur at any age. (sharecare.com)
- Unlike wild-type animals, the daf-2(e1370) animals have an enhanced anoxia-survival phenotype in that they survive long-term anoxia and high-temperature anoxia, do not accumulate significant tissue damage in either of these conditions, and are motile after 24 hr of anoxia. (genetics.org)
- RNA interference was used to screen DAF-16-regulated genes that suppress the daf-2(e1370) -enhanced anoxia-survival phenotype. (genetics.org)
- The long-term anoxia survival phenotype of dauer larvae is consistent with its ability to survive stress. (genetics.org)
- Cardiac survival in anoxia-tolerant vertebrates: An electrophysiological perspective. (biomedsearch.com)
- Presentation for the 2008 University Scholars Day at the University of North Texas discussing sex, stress, oxygen deprivation, and gender-specific phenotypes modulate survival in anoxia. (unt.edu)
- Of species tested, C. macellaria withstood the longest period of anoxia ( LT 50 of 9 h at 20 o C). In contrast, C. vicina was the least tolerant (LT 50 of 2.2 h at 40 o C). Overall, survival of P. regina showed the least response and C. macellaria showed the greatest response to temperature. (unl.edu)
- Lutz, J. Pablo, and D. Mash, Downregulation of sodium channels during anoxia: a putative survival strategy of turtle brain. (springer.com)
- We hypothesized that activation of ChREBP could be relevant to anoxia survival by the anoxia-tolerant turtle, Trachemys scripta elegans. (chalmers.se)
- Pea and rice seedlings were exposed to anoxia for 1 to 24 h and their tolerances and survival compared. (st-andrews.ac.uk)
- Mathew Pamenter, a graduate student in the lab, had the idea to investigate a relatively newly discovered potassium channel (mitochondrial KATP channel) as a possible regulator of NMDA receptor activity during anoxia. (eurekalert.org)
- Perez-Pinzon, M.A., C.Y. Chan, M. Rosenthal, and T.J. Sick, Membrane and synaptic activity during anoxia in the isolated turtle cerebellum. (springer.com)
- Here, we show that anoxia reduces expression of thrombospondin-1 (TSP-1), a natural inhibitor of angiogenesis, in glioblastoma cells. (rupress.org)
- Together, our results show that anoxia induced a greatly reduced rate of heterotrophic metabolism in Ammonia tepida on a time scale of less than 24 hours, these observations are consistent with a state of dormancy. (epfl.ch)
- Anemic anoxia takes place where there is not enough hemoglobin in a person's blood, or the hemoglobin present has become ineffective. (medicalnewstoday.com)
- Anemic anoxia occurs when your blood can't carry enough oxygen around your body to keep your organs functioning properly. (healthline.com)
- This lack of oxygen can cause anemic anoxia. (healthline.com)
- Anemic anoxia results from a decrease in the amount of hemoglobin or RBCs in the blood, which reduces the ability to get oxygen to the tissues. (thefreedictionary.com)
- Complete mitochondrial genomes of the yellow-bellied slider turtle Trachemys scripta scripta and anoxia tolerant red-eared slider Trachemys scripta. (nih.gov)
- The complete mitochondrial genomes of the yellow-bellied slider (Trachemys scripta scripta) and anoxia tolerant red-eared slider (Trachemys scripta elegans) turtles were sequenced to analyze gene arrangement. (nih.gov)
- Persistent environmental stresses such as hyperwarming and ocean anoxia may have delayed the biotic recovery [1,2, (confex.com)
- In order to characterize the duration and extent of ocean anoxia after the LPME, we have measured the U isotope composition (δ 238 U) - a proxy for global ocean anoxia - in well-preserved marine carbonates across the Late Permian to the Middle Triassic at Zal (Iran). (confex.com)
- The nature of the protracted global ocean anoxia might be a key and direct factor that caused the delayed biotic recovery from the LPME. (confex.com)
- This impact of bioturbation on global biogeochemistry likely affected animal evolution through expanded ocean anoxia, high atmospheric CO2 levels and global warming. (tudelft.nl)
- These data indicate that the worst part of the F-F extinction was not related directly to oceanic anoxia in this region and potentially globally. (usgs.gov)
- Apoptosis has been shown to be involved in mitochondrial dysfunction, and upregulating expression of SIRT1 can inhibit the apoptosis of cardiomyocytes induced by anoxia/reoxygenation (A/R). Therefore, the aim of this study was to test whether the protective effects of Cap against the injury to the cardiomyocytes are mediated by SIRT1. (hindawi.com)
- Objective: To study the protective effect of β carotene in anoxia injured cardiomyocytes. (cnki.com.cn)
- WT5FZ]Methods: The cultured rat neonatal cardiomyocytes were subjected to 2h anoxia and the changes of lactate dehydrogenase(LDH) activity, malondialdehyde (MDA), oxygen free radical (OFR) contents and superoxide dismutase (SOD) activity were detected. (cnki.com.cn)
- Results: The LDH, MDA, OFR and SOD of cardiomycytes were changed significantly after 2h anoxia (P0.01).However, the β carotene pre treated cardiomyocytes showed less changes. (cnki.com.cn)
- Conclusion: β carotene (10 -2 ～10 -1 ) mmol/L can protect cardiomyocytes from anoxia injury. (cnki.com.cn)
- During anoxia/reoxygenation (A/R) injury, intracellular chloride ion concentration ([Cl - ] i ) homeostasis may play a role in maintaining the normal physiological function of cardiomyocytes. (biomedcentral.com)
- The results showed that rice, a species highly tolerant to anoxia, can readily break down starch under anaerobiosis concomitant with germination, while wheat does not germinate and fails to degrade starch present in the endosperm. (nih.gov)
- Small ncRNA profiles were broadly conserved among species under normoxic conditions, and these expression patterns were largely conserved during exposure to anoxia. (frontiersin.org)
- Indeed, some species are able to survive complete anoxia for weeks to months. (epfl.ch)
- From the results presented in this thesis and elsewhere, it is concluded that-the immediate cause of seedling death during anoxia is a shortage of substrate for glycolysis, and that the additional effect of ethanol accumulation in some species may reduce their subsequent rate of recovery. (st-andrews.ac.uk)
- Anoxia/reoxygenation (A/R) injury refers to a phenomenon in which ischemia/reperfusion (I/R) myocardial tissues aggravate the injury to myocardial structures and functions [ 1 ], which can lead to arrhythmia, heart hypofunction, cardiomyocyte apoptosis, and other disorders [ 2 ]. (hindawi.com)
- Another possibility is that anoxia in itself does not induce apoptosis, but that the following reoxygenation causes increased apoptosis. (uio.no)
- some survive days or even years of hypoxia or anoxia. (genetics.org)
- Yet, further studies are needed to understand the molecular mechanism that the dauer larvae use to survive anoxia. (genetics.org)
- It is not clear whether flood-tolerant plants survive in waterlogged soils because they maintain aerobic activity in all regions of the roots, or whether biochemical adaptations to anoxia are involved. (st-andrews.ac.uk)
- Low temperature pre-conditions fish heart for prolonged anoxia by changes in activity of excitation-contraction coupling genes and thereby allows sustained bradycardia and prolongation of ventricular action potential when oxygen shortage sets in. (biologists.org)
- Red dots represent genes induced or repressed by either anoxia or heat, while blue dots represent genes that were not found to be heat responsive. (plantphysiol.org)
- A, Heat map showing the expression of anaerobic genes showing a reduced expression in the combined heat + anoxia treatment. (plantphysiol.org)
- Anoxia-induced Suc synthases showed a lower induction in presence of exogenous Suc, suggesting that induction of these genes might be related to an anoxia-dependent sugar starvation. (plantphysiol.org)
- Anoxia is a condition characterized by an absence of oxygen supply to an organ or a tissue. (thefreedictionary.com)
- When the tissue or organ itself has a reduced ability to accept and use the oxygen, it is called histotoxic anoxia. (thefreedictionary.com)
- Anoxia occurs when oxygen is absent or depleted and unable to properly reach organs or tissue. (alleydog.com)
- Effects of HypoThermosol, an experimental acellular solution for tissue preservation and cardiopulmonary bypass, on isolated newborn lamb coronary vessels subjected to ultra profound hypothermia and anoxia. (biolifesolutions.com)
- It reduces the inflow of calcium through NMDA receptors during anoxia and is associated with brain protection. (eurekalert.org)
- Employing cell-attached single-channel patch-clamp techniques, we studied the effect of adenosine (200 micromol l-1) and anoxia on NMDA receptor open probability (Popen) and current amplitude. (biologists.org)
- Therefore, during anoxia, NMDA receptors cannot be regulated by Mg2+ in a manner dependent on membrane potential. (biologists.org)
- We conclude that anoxia modulates NMDA receptor activity and that adenosine plays a key role in mediating this change. (biologists.org)
- For example, calculations based on creatine phosphate depletion and lactate accumulation during anoxia suggested that ATP production was markedly reduced (by approx 88%) [1, (springer.com)
- Hearts from the reserpine-treated rats had higher left ventricular pressures, maximal rate of left ventricular pressure rise, and lactate output after 2 minutes of anoxia than the hearts from control rats. (ahajournals.org)
- Anoxia n : the absence of oxygen in inspired gases or in arterial blood or in the tissues. (paranormality.com)
- Affinity anoxia involves a defect in the chemistry of the blood such that the hemoglobin can no longer pick up as much oxygen from the air, even though the quantities are normal, reducing how much is delivered to the tissues. (thefreedictionary.com)
- Anoxia is a scientific term which refers to insufficient oxygen levels in the tissues of an organ, despite unrestricted blood flow. (medicalmalpracticehelp.com)
- Enhanced nuclear presence under anoxia was also observed in both tissues by 22-2.8 fold. (chalmers.se)
- Cardiovascular variables were continuously monitored during normoxia, 2 h of anoxia, and during recovery at normoxia. (nih.gov)
- Because anoxia causes significant amounts of distress to the cardiovascular and respiratory systems, it is essential to identify and treat the problem with haste. (medicalmalpracticehelp.com)
- It was concluded that 1) N2-delivery patterns consisting of long anoxia, short normoxia and high cycle frequency increased disruption of brain [K+]o baseline maintenance, 2) males were more susceptible to repeated anoxia than females at room temperature, and 3) hypothermia had a protective effect on brain K+ homeostasis during repetitive anoxia. (queensu.ca)
- Transcriptome analysis of anoxia-, heat-, and heat + anoxia-treated Arabidopsis seedlings. (plantphysiol.org)
- H 2 O 2 (5 m m ) was added (2-h treatment) to the wells containing the seedlings followed by rinsing in fresh medium and transfer to anoxia (26 h). (plantphysiol.org)
- We used the Affymetrix ATH1 GeneChip containing more than 22,500 probe sets to explore the anaerobic transcriptome of Arabidopsis seedlings kept under anoxia for 6 h in presence or absence of exogenous Suc. (plantphysiol.org)
- to characterize the response of Arabidopsis seedlings treated for 6 h under anoxia in presence or absence of exogenous Suc. (plantphysiol.org)
- We used anoxia to obtain a rapid anaerobic response and choose seedlings as they represent a very homogeneous plants material at a growth stage at which plants often experience low oxygen conditions ( Perata and Alpi, 1993 ). (plantphysiol.org)
- Increasing amounts of K+ were lost from the roots of whole seedlings during anoxia, and seedling recovery on return to air was associated with the seedlings' ability to reabsorb most of the leaked K+. (st-andrews.ac.uk)
- Aerobic respiration in the root tips was associated with both K+ uptake by pea seedlings, and the recovery and subsequent growth of pea and three varieties of rice after anoxia. (st-andrews.ac.uk)
- Although some pea and rice seedlings appeared undamaged after anoxia, the subsequent growth rates of pea and rice, cv. (st-andrews.ac.uk)
- Pea seedlings that were prevented from transpiring during anoxia were damaged earlier than controls, possibly because of an increase in the rate of accumulation of a toxic product of anaerobic metabolism in these seedlings. (st-andrews.ac.uk)
- Two percent glucose merely delayed, and did not prevent, the onset of damage in whole pea seedlings during anoxia, nor did it enhance the subsequent growth of the seedlings. (st-andrews.ac.uk)
- Fetal anoxia may occur from inadequate oxygenation of the mother, low maternal blood pressure, or abnormalities in the uterus, placenta, or umbilical cord that result in inadequate blood flow to the fetus. (britannica.com)
- Anoxia" means "total absence of oxygen," and in Lea's hands the term heralds aural environments that are full of the dreams of humanity yet may well be devoid of its living presence. (forcedexposure.com)
- For the autumn period each profile in the dataset was examined for the occurrence of hypoxia (oxygen deficiency) and anoxia (total absence of oxygen). (smhi.se)
- Anoxia with posttraumatic amnesia Hello there, This is a serious attempt to find more information and consultation from various experts around the world within the field of neuropsychology. (bio.net)
- Anoxia has been shown to cause brain damage that can have lasting consequences like amnesia. (alleydog.com)
- Toxic anoxia stops the blood from carrying oxygen around the body effectively. (medicalnewstoday.com)
- Carbon monoxide poisoning is one of the most common causes of toxic anoxia. (healthline.com)
- How do medications treat toxic anoxia? (sharecare.com)
- Although medication is generally not the primary treatment for toxic anoxia, it is important in some cases. (sharecare.com)
- Medication used to treat toxic anoxia works by stabilizing the brain or by reversing the chemical problem that caused the condition. (sharecare.com)
- More importantly, medications may be used as antidotes for the common poisons that cause toxic anoxia. (sharecare.com)