glycogen and Heart-Diseases

Cardiac glycogen regulation involves a complex interplay between multiple signalling pathways, allosteric activation of enzymes, and sequestration for autophagic degradation. Signalling pathways appear to converge on glycogen regulatory enzymes via insulin (glycogen synthase kinase 3β, protein phosphatase 1, allosteric action of glucose-6-phosphate), β-adrenergic (phosphorylase kinase protein phosphatase 1 inhibitor), and 5' adenosine monophosphate-activated protein kinase (allosteric action of glucose-6-phosphate, direct glycogen binding, insulin receptor). While cytosolic glycogen synthesis and breakdown are relatively well understood, recent findings relating to phagic glycogen degradation highlight a new area of investigation in the heart. It has been recently demonstrated that a specific glycophagy pathway is operational in the myocardium. Proteins involved in recruiting glycogen to the forming phagosome have been identified. Starch-binding domain-containing protein 1 is involved in binding glycogen and mediating membrane anchorage via interaction with a homologue of the phagosomal protein light-chain 3. Specifically, it has been shown that starch-binding domain-containing protein 1 and light-chain 3 have discrete phagosomal immunolocalization patterns in cardiomyocytes, indicating that autophagic trafficking of glycogen and protein cargo in cardiomyocytes can occur via distinct pathways. There is strong evidence from glycogen storage diseases that phagic/lysosomal glycogen breakdown is important for maintaining normal cardiac glycogen levels and does not simply constitute a redundant 'alternative' breakdown route for glycogen. Advancing understanding of glycogen handling in the heart is an important priority with relevance not only to genetic glycogen storage diseases but also to cardiac metabolic stress disorders such as diabetes and ischaemia.

Topics: Animals; Energy Metabolism; Glycogen; Glycogen Storage Disease; Heart Diseases; Humans; Kinetics; Lysosomes; Myocardium; Phagosomes; Signal Transduction

An understanding of the role of autophagic processes in the management of cardiac metabolic stress responses is advancing rapidly and progressing beyond a conceptualization of the autophagosome as a simple cell recycling depot. The importance of autophagy dysregulation in diabetic cardiomyopathy and in ischemic heart disease - both conditions comprising the majority of cardiac disease burden - has now become apparent. New findings have revealed that specific autophagic processes may operate in the cardiomyocyte, specialized for selective recognition and management of mitochondria and glycogen particles in addition to protein macromolecular structures. Thus mitophagy, glycophagy, and macroautophagy regulatory pathways have become the focus of intensive experimental effort, and delineating the signaling pathways involved in these processes offers potential for targeted therapeutic intervention. Chronically elevated macroautophagic activity in the diabetic myocardium is generally observed in association with structural and functional cardiomyopathy; yet there are also numerous reports of detrimental effect of autophagy suppression in diabetes. Autophagy induction has been identified as a key component of protective mechanisms that can be recruited to support the ischemic heart, but in this setting benefit may be mitigated by adverse downstream autophagic consequences. Recent report of glycophagy upregulation in diabetic cardiomyopathy opens up a novel area of investigation. Similarly, a role for glycogen management in ischemia protection through glycophagy initiation is an exciting prospect under investigation.

Topics: Animals; Autophagy; Energy Metabolism; Glycogen; Heart Diseases; Humans; Mitophagy; Myocardium; Oxidative Stress

The Authors review several pharmacological interventions aimed at protecting the ischemic myocardium. Drugs which have been widely used in the treatment of ischemic heart diseases, such as beta-blockers, nitrates and calcium-antagonists, are able to delay the development of ischemic injury if administered before the beginning of ischemia, but their clinical effectiveness is limited. The new drugs which are presently investigated are designed to counteract the molecular mechanisms which mediate irreversible tissue injury, namely cytosolic calcium overload, cellular hyperosmolarity, and free radical production. In particular, interventions able to interfere with the release of calcium from its intracellular stores would be of major importance. In this regards, it is interesting to point out that derivatives of phenylalkylamine calcium-antagonists have been reported to modulate the opening probability of sarcoplasmic reticulum calcium channels.

Topics: Adenosine; Adrenergic beta-Antagonists; Calcium; Calcium Channel Agonists; Calcium Channels; Glycogen; Heart Diseases; Heat-Shock Proteins; Humans; Myocardial Ischemia; Myocardial Reperfusion; Potassium Channels; Sodium Channels

Geriatric cardiology requires special knowledge and experience. It is not possible to extrapolate directly experience obtained with young patients to old people. Because of the multiple illnesses, many serious, in the elderly cardiac patients, it is imperative for the cardiologist to be, first of all, a master internist at all times. Old patients with their multiple illnesses are also sensitive to drugs, including digitalis and diuretics. There is a need to train more physicians in geriatric cardiology in order to offer the old patient the best of care since so many old people are living today. There is also a need to learn the effects of the aging process itself on the human heart. Such studies should command priorities in financial and other forms of support.

Topics: Age Factors; Aging; Aortic Valve Insufficiency; Aortic Valve Stenosis; Cardiac Output; Dyspnea; Edema; Electrocardiography; Female; Glycogen; Heart; Heart Diseases; Heart Function Tests; Histocytochemistry; Humans; Hypertension; Hypotension, Orthostatic; Male; Microscopy, Electron; Myocardium; Radiography; Rheumatic Heart Disease; Thyroid Diseases; Vectorcardiography

Topics: Aged; Aging; Animals; Coronary Disease; Coronary Vessels; Dihydrolipoamide Dehydrogenase; Female; Glucosephosphate Dehydrogenase; Glycerolphosphate Dehydrogenase; Glycogen; Heart Diseases; Humans; Hydroxybutyrate Dehydrogenase; L-Lactate Dehydrogenase; Malate Dehydrogenase; Male; Myocardium; Organ Size; Rats; Succinate Dehydrogenase

Topics: Fatty Acids, Nonesterified; Glucose; Glucosyltransferases; Glycogen; Glycolysis; Heart Diseases; Heart Failure; Humans; Hydrogen-Ion Concentration; Hypoxia; Ketone Bodies; Lipid Metabolism; Myocarditis; Myocardium; Oxidative Phosphorylation; Phosphofructokinase-1; Pyruvates; Triglycerides

Topics: Glycogen; Heart Diseases; Humans; Sugars

PRKAG2 cardiac syndrome is a distinct form of human cardiomyopathy characterized by cardiac hypertrophy, ventricular pre-excitation and progressive cardiac conduction disorder. However, it remains unclear how mutations in the PRKAG2 gene give rise to such a complicated disease. To investigate the underlying molecular mechanisms, we generated disease-specific hiPSC-derived cardiomyocytes from two brothers both carrying a heterozygous missense mutation c.905G>A (R302Q) in the PRKAG2 gene and further corrected the R302Q mutation with CRISPR-Cas9 mediated genome editing. Disease-specific hiPSC-cardiomyocytes recapitulated many phenotypes of PRKAG2 cardiac syndrome including cellular enlargement, electrophysiological irregularities and glycogen storage. In addition, we found that the PRKAG2-R302Q mutation led to increased AMPK activities, resulting in extensive glycogen deposition and cardiomyocyte hypertrophy. Finally we confirmed that disrupted phenotypes of PRKAG2 cardiac syndrome caused by the specific PRKAG2-R302Q mutation can be alleviated by small molecules inhibiting AMPK activity and be rescued with CRISPR-Cas9 mediated genome correction. Our results showed that disease-specific hiPSC-CMs and genetically-corrected hiPSC-cardiomyocytes would be a very useful platform for understanding the pathogenesis of, and testing autologous cell-based therapies for, PRKAG2 cardiac syndrome.

Topics: Adult; AMP-Activated Protein Kinases; Base Sequence; Calcium; Cardiomegaly; Cell Differentiation; Electrophysiological Phenomena; Glycogen; Heart Diseases; Humans; Induced Pluripotent Stem Cells; Male; Mitochondria; Models, Biological; Mutation; Myocardial Contraction; Myocytes, Cardiac; Oxidation-Reduction; Phenotype; Reproducibility of Results; Syndrome

The purpose of the present study was to determine calorimetric parameters to predict obesity adverse effects on oxidative stress and cardiac energy metabolism. Male Wistar 24 rats were divided into three groups (n = 8): given standard chow and water (C), receiving standard chow and 30% sucrose in its drinking water (S), and given sucrose-rich diet and water (SRD). After 45 days, both S and SRD rats had obesity, serum oxidative stress, and dyslipidemic profile, but the body weight gain and feed efficiency (FE) were higher in SRD than in S, whereas the obesity-related oxidative stress, myocardial triacylglycerol accumulation, and enhanced cardiac lactate dehydrogenase (LDH) activity were higher in S than in SRD rats. Myocardial beta-hydroxyacyl coenzyme-A-dehydrogenase was lower in SRD and in S than in C, whereas glycogen was only depleted in S rats. Myocardial pyruvate dehydrogenase (PDH) was lowest in S rats indicating depressed glucose oxidation. There was higher myocardial LDH/citrate synthase (CS) ratio and lower adenosine triphosphate (ATP)-synthetase indicating delayed aerobic metabolism in S rats than in the others. Cardiac ATP-synthetase was positively correlated with energy expenditure, namely resting metabolic rate (RMR), and with oxygen consumption per body weight (VO(2)/body weight). Myocardial lipid hydroperoxide (LH)/ total antioxidant substances (TAS) ratio and triacylglycerol accumulation were negatively correlated with RMR and with VO(2)/body weight. In conclusion, the present study brought new insights into obesity because the study demonstrated for the first time that reduced energy expenditure and oxygen consumption may provide novel risk factors of obesity-induced reduced energy generation for myocardial contractile function. The results serve to highlight the role of calorimetric changes as novel biomarkers of risk to obesity-induced cardiac effects.

Topics: Animals; Antioxidants; ATP Synthetase Complexes; Basal Metabolism; Biomarkers; Blood Glucose; Citrate (si)-Synthase; Dietary Sucrose; Energy Metabolism; Enzymes; Glycogen; Heart; Heart Diseases; Lipid Peroxides; Male; Myocardium; Obesity; Oxidation-Reduction; Oxidative Stress; Oxidoreductases; Oxygen Consumption; Rats; Rats, Wistar; Triglycerides; Weight Gain

Pharmacological and metabolic effects of Galleria mellonella larvae extract used in Russian folk medicine to treat cardiovascular and senile diseases were studied. It was shown that the extract possesses adaptogenic, cardiotropic, cardioprotective, and hypocoagulant properties. The extract possesses low toxicity and does not cause significant changes in biochemical parameters in the blood serum of laboratory animals. Increase in catecholamine content in the heart and aortic tissues and their decrease in adrenal glands are unfavourable effects of high doses of the extract.

Topics: Adaptation, Physiological; Animals; Anura; Blood Coagulation; Epinephrine; Glycogen; Heart; Heart Diseases; In Vitro Techniques; Kidney Function Tests; Moths; Muscle, Smooth, Vascular; Myocardium; Norepinephrine; Organ Size; Physical Endurance; Rats; Strophanthins; Tissue Extracts

Prevention by manganese ions of heart injury induced by the calcium paradox was studied in isolated perfused rat heart. Lactate dehydrogenase (LDH) release, ATP and glycogen content, and 45Ca2+ accumulation were used as markers of the injury. If Mn2+ substituted Ca2+ in the perfusion buffer after Ca2+-free perfusion, LDH release from the heart was inhibited but the inhibition was eliminated by Ca2+ readmission. However, Mn2+ (0.2-2.5 mM), added from the beginning of Ca2+-free perfusion, prevented heart injury at the time of Ca2+ repletion. LDH release and 45Ca2+ accumulation in the myocardium were reduced by 90-99%; ATP, glycogen and water content in the heart as well as perfusion pressure and heart rate remained within control values. The observed protective effect of Mn2+ was proportional to its concentration, and to the duration of Ca2+-free perfusion. A possible explanation for the protective effect of Mn2+ ions can be competition with Ca2+ binding sites related to sarcolemma integrity.

Topics: Adenosine Triphosphate; Animals; Binding Sites; Calcium; Calcium Radioisotopes; Glycogen; Heart Diseases; L-Lactate Dehydrogenase; Male; Manganese; Myocardium; Rats; Rats, Inbred Strains; Sarcolemma

It has been established that sodium hydroxybutyrate, prolactin, propranolol and ionol are capable of preventing the depression of the contractile function of the heart and of decreasing the glycogen level in the myocardium, provoked by emotional stress.

Topics: Animals; Butylated Hydroxytoluene; Drug Evaluation, Preclinical; Glycogen; Heart Diseases; Humans; Male; Myocardial Contraction; Myocardium; Prolactin; Propranolol; Rats; Sodium Oxybate; Stress, Psychological

A comparative study of the beta-receptor blockers propranolol, pindolol and carazolol, with respect to their cardio-protective properties against stress (hypoxia or isoprenaline injection) in rats showed the following. The beta-blockers investigated protected the heart against glycogen depletion during hypoxia. Carazolol was active at considerably lower doses than pindolol (about 25 times less) and propranolol (about 100 times later). All three beta-blockers protected against the induction of cardiac necroses by isoprenaline, but only carazolol produced almost complete protection. There is a good correlation between the protection against the development of cardiac necroses and the inhibition of tachycardia induced by isoprenaline (r = 0.96). The results are discussed from the point of view of the possible mechanisms by which the beta-blockers prevent cardiac damage induced by stress situations.

Topics: Adrenergic beta-Antagonists; Animals; Coronary Disease; Glycogen; Heart Diseases; Isoproterenol; Membranes; Myocardium; Pindolol; Propanolamines; Propranolol; Rats; Rats, Inbred Strains

Furazolidone (FZ) at 700 ppm was added to feed mixtures fed turkey poults 2--5 weeks after hatching to induce acute experimental cardiomyopathy. Poults in the control pen received the same ration but without FZ. From EKG data obtained at weekly intervals, poults were selected for sacrifice at 5 and 10 weeks of age. Poults were sacrificed by cervical dislocation and appropriate samples of tissue from the left ventricle, liver, pectoralis and tibialis cranialis muscles were removed for glycogen assays. Character of glycogen, as determined by percent of branching and number of glucose units per segment, was not significantly altered in poults with spontaneous round heart disease or FZ-induced cardiomyopathy. This suggests that the glycogen accumulation noted in these conditions most closely resembles type II glycogenosis.

Topics: Animals; Cardiomyopathies; Furazolidone; Glucose; Glycogen; Glycogen Storage Disease; Glycogen Storage Disease Type II; Heart Diseases; Liver; Liver Glycogen; Muscles; Myocardium; Pectoralis Muscles; Poultry Diseases; Turkeys

Ten dogs underwent orthotopic cardiac transplantation after preservation of the donor heart for 24 hours in an oxygenated hypothermic, hypertonic, intracellular solution, either with (five dogs) or without (five dogs) continuous, oxygenated, low-pressure perfusion. Eight dogs survived for 24 hours after transplantation, at which time they were put to death. The two nonsurvivors were among the five with nonperfused hearts. Examination of all 10 donor hearts showed differences between the two groups: Four of five nonperfused hearts showed severe transmural myocardial coagulation necrosis but only small foci of contraction band necrosis (myofibrillar degeneration). The perfused hearts, however, showed more extensive subendocardial areas of contraction-band necrosis, but only minimal and focal coagulation necrosis, indicating less severe hypoxic damage. These results indicate that oxygenated perfusion with a hypothermic, hypertonic, intracellular solution may permit improved transplant survival after extended cardiac preservation.

Topics: Animals; Dogs; Glycogen; Heart; Heart Diseases; Heart Transplantation; Hemorrhage; Hypertonic Solutions; Hypothermia, Induced; Myocardium; Organ Preservation; Organ Size; Perfusion; Postoperative Complications; Tissue Preservation; Transplantation, Homologous

Topics: Animals; Benzoates; Ganglionic Blockers; Glycogen; Heart Diseases; Muscle Proteins; Myocardial Contraction; Myocardium; Quaternary Ammonium Compounds; Rats; RNA

Topics: Adult; Animals; Cardiomegaly; Cell Nucleus; Child; Glycogen; Heart Diseases; Histocytochemistry; Humans; Male; Mice; Middle Aged; Myocardium; Phosphorylases; Rats

Multifocal Purkinje cell tumors were found in the heart of a nine-month-old black female infant who died with arrhythmias which had become progressively more frequent and severe until they were completely intractable. The Purkinje cell tumors were composed of exactly the same type of cells found in the left bundle branch and the right bundle branch, and they were also located in the expected region of the His bundle. In none of these locations were these Purkinje cells forming normal longitudinally oriented Purkinje fibers, however, and no such fibers were found anywhere in this heart. The cells of the tumors contained glycogen but not in excess of that normally expected to be present in Purkinje cells. No evidence for a generalized abnormality of glycogen metabolism or storage was present. Except for the Purkinje cells, the remaining myocardial cells of the heart were all normal. The fundamental fault appeared to be failure of the Purkinje cells to organize into the normal histological pattern which is characterized by longitudinally oriented Purkinje fibers. Instead, all the Purkinje cells were rounded or polygonal and generally aggregated together into small discrete nodules of varying size. Future cases of this nature deserve careful attention to the nature of their cardiac rhythm and conduction, and in fatal cases there should be special studies of the histological appearance of their cardiac centers of impulse formation and conduction.

Topics: Arrhythmias, Cardiac; Autopsy; Cell Differentiation; Diagnosis, Differential; Electrocardiography; Female; Glycogen; Glycogen Storage Disease; Heart; Heart Diseases; Humans; Inclusion Bodies; Infant; Microscopy, Electron; Myocardium; Purkinje Cells

The present study was undertaken to determine the involvement of cardiac lyososomes in injury to the myocardium after cardiopulmonary bypass. Twenty conditioned mongrel dogs, weighing 15 to 18 kilograms, were fasted overnight, anesthetized with sodium pentobarbital (30 mg. per kilogram), intubated, and maintained on positive-pressure ventilation. The femoral artery and femoral vein were cannulated for pressure measurements. After median sternotomy, intravenous heparin was administered (3 mg. per kilogram) before the aorta and the superior and inferior venae cavae were cannulated for bypass. Bypass was instituted with a Travenol modular pump and a Bentley pediatric bubble oxygenator and heat exchanger. The ultrastructural effects on the myocardium and the acid phosphatase activity in the left ventricle were compared in dogs exposed to bypass for 1 hour with varying types of myocardial support: perfusion of the coronary arteries, normothermic ischemic arrest, or selective cardiac hypothermia. The morphology of control hearts and hearts fixed after 1 hour of coronary perfusion were similar. The distribution and structure of subcellular lysosomes were the same and showed identical patterns of acid phosphatase activity. Normothermic ischemic arrest was associated with a loss of glycogen stores, disrupted sarcoplasmic reticulum and T tubules, vacuolization and decrease in matrix density of mitochondria, and separation of the intercalated discs. Lysosomal activity was absent except for occasional residual bodies in the nuclear pole zone of the myocardial cells. Selective cardiac hypothermia produced results superior to those from normothermic ischemic arrest. Although these hearts showed proliferation of the lysosomal compartment, the organelles responsible for excitation-contraction coupling were spared.

Topics: Acid Phosphatase; Animals; Cardiopulmonary Bypass; Coronary Disease; Dogs; Extracorporeal Circulation; Glycogen; Heart Arrest; Heart Diseases; Lysosomes; Mitochondria, Muscle; Myocardium; Sarcoplasmic Reticulum; Time Factors

Vesicular myocardial change is a specific and common finding in the diseased hearts of humans and experimental animals. The small to large vesicles are generally bound by a double membrane. They are formed within myocardial cells and then possibly extruded into the extracellular space where they disintegrate or are phagocytosed by mononuclear cells. On the basis of our studies, most vesicles appear to be of mitochonrial origin. In humans, vesicular myocardial change appears to be most extreme in primary cardiomyopathy. It may also be present, but in lesser degree, in the apparently normal hearts of human adults. Vesicular myocardial change probably represents a specific mechanism by which myocardial cells eliminate damage mitochondria or other undesirable elements that build within them as a result of disease, aging, and perhaps normal physiological activity.

Topics: Adolescent; Adult; Animals; Cardiomyopathies; Extracellular Space; Female; Glycogen; Heart Diseases; Humans; Male; Membranes; Middle Aged; Mitochondria, Muscle; Myocardium; Myofibrils; Phagocytosis; Sarcolemma

The effect of ethanol on the myocardial metabolism of experimental animals was studied in acute and in chronic models. Thirty minutes after intraperitoneal injection of ethanol in a dose of 250 mg/100 gm of body weight there was a significant increase of glycolysis and slight decrease of mitochondrial respiration as well as of respiratory control ratio. No changes were observed in the concentration of high energy phosphates in the heart muscle. The metabolic changes in these acute experiments were of a transitory character; they disappeared parallel with the decline of ethanol level in the blood and in the myocardium. The chronic alcoholic model was observed for 10 weeks. Ethanol (250 mg/100 gm) was injected daily. The analyses of the heart muscle were carried out 24 hr after the last injection of ethanol. In this model ethanol also provoked considerable disturbances of metabolic processes in the myocardium: decrease of glycolysis and of glycogen content, decrease of mitochondrial respiration as well as of respiratory control ratio of isolated mitochondria and decrease of adenosine triphosphate and creatine phosphate with simultaneous increase of inorganic phosphate in the myocardium.

Topics: Adenosine Triphosphate; Animals; Ethanol; Glycogen; Glycolysis; Heart; Heart Diseases; Mitochondria, Muscle; Myocardium; Oxygen Consumption; Phosphates; Phosphocreatine; Rats

Topics: Animals; Glycogen; Heart Diseases; Isocitrate Dehydrogenase; Isoenzymes; L-Lactate Dehydrogenase; Lactates; Malate Dehydrogenase; Mitochondria, Muscle; Mitochondrial Swelling; Myocardium; Oxidative Phosphorylation; Oxygen Consumption; Plant Poisoning; Rabbits; Seeds; Senna Extract

Topics: Adenosine Triphosphate; Animals; Glucose; Glycogen; Heart; Heart Diseases; Hypoxia; Isoproterenol; Lactates; Male; Myocardium; Necrosis; Perfusion; Phosphocreatine; Rats; Time Factors

Topics: Cells, Cultured; Culture Media; DNA; Fibroblasts; Glucosidases; Glucosyltransferases; Glycogen; Glycogen Storage Disease; Glycogen Synthase; Glycoside Hydrolases; Heart Diseases; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Liver Diseases; Methods; Muscular Diseases; Phosphorylases; Proteins

Topics: Adult; Animals; Cardiomegaly; Cell Nucleus; Dogs; Endocardial Fibroelastosis; Glycogen; Heart Arrest; Heart Diseases; Heart Failure; Humans; Hypoxia; Male; Middle Aged; Mitochondria, Muscle; Myocardium; Tetralogy of Fallot; Wolff-Parkinson-White Syndrome

Topics: Animals; Coronary Circulation; Disease Models, Animal; Dogs; Extracorporeal Circulation; Glycogen; Heart Arrest, Induced; Heart Diseases; Heart Ventricles; Histocytochemistry; Ischemia; Magnesium Sulfate; Microscopy, Electron; Myocardium; Perfusion; Postoperative Complications; Time Factors

Topics: Adaptation, Physiological; Adult; Altitude; Animals; Bolivia; Disease Models, Animal; Glucose; Glycogen; Heart Diseases; Hexosephosphates; Humans; Hypoxia; Lactates; Oxygen Consumption; Peru; Pyruvates; Rats

Topics: Carbon Isotopes; Cardiomegaly; Cell Line; Chromatography, Paper; Disaccharides; Fibroblasts; Glucose; Glucosidases; Glycogen; Glycogen Storage Disease; Half-Life; Heart Defects, Congenital; Heart Diseases; Humans; Skin

Topics: Biopsy; Cardiomegaly; Child, Preschool; Glucosidases; Glycogen; Glycogen Storage Disease; Heart Defects, Congenital; Heart Diseases; Humans; Male; Microscopy, Electron; Oculomotor Muscles

Topics: Animals; Cardiomegaly; Chromatography, Gel; Cross Reactions; Female; Glucosidases; Glycogen; Glycogen Storage Disease; Heart Defects, Congenital; Heart Diseases; Humans; Hydrogen-Ion Concentration; Hydrolysis; Immunodiffusion; Immunoglobulins; Kinetics; Liver; Lysosomes; Maltose; Mice; Placenta; Pregnancy; Rabbits; Rats

Topics: Glycogen; Glycogen Storage Disease; Heart Diseases; Humans; Myocardium

Topics: Adult; Age Factors; Cell Membrane; Cells, Cultured; Cytoplasm; Fascia; Fibroblasts; Glucosidases; Glycogen; Glycogen Storage Disease; Heart Diseases; Histocytochemistry; Humans; Hydrogen-Ion Concentration; Maltose; Microscopy, Electron; Middle Aged; Muscular Diseases; Skin

Topics: Animals; Calcium; Coronary Disease; Endoplasmic Reticulum; Glycogen; Heart; Heart Diseases; Histocytochemistry; Isoproterenol; Male; Microscopy, Electron; Mitochondria; Myocardium; Propranolol; Rats

Topics: Blood; Cleft Lip; Glycogen; Glycolysis; Heart Diseases; Humans; Hypoxia; Immunization, Passive; Oxygen Consumption

Topics: Animals; Cardiomegaly; Glucosidases; Glycogen; Glycogen Storage Disease; Heart Defects, Congenital; Heart Diseases; Male; Microscopy, Electron; Rats; Syndrome

Topics: Biopsy; Cardiomegaly; Diagnosis, Differential; Glucose-6-Phosphatase; Glucosidases; Glucosyltransferases; Glycogen; Glycogen Storage Disease; Glycoside Hydrolases; Heart Defects, Congenital; Heart Diseases; Humans; Infant; Liver; Male; Methods; Muscles; Muscular Diseases; Skin

Topics: Acid Phosphatase; Axons; Brain; Brain Chemistry; Cell Nucleus; Cytoplasm; Glucosidases; Glucosyltransferases; Glycogen; Glycogen Storage Disease; Heart Diseases; Humans; Infant; Lysosomes; Male; Microscopy; Microscopy, Electron; Mitochondria; Myelin Sheath; Nervous System; Nervous System Diseases; Neuroglia; Neurons; Peripheral Nerves; Schwann Cells; Spinal Cord

1. The maltase and glucoamylase activities of acid alpha-glucosidase purified from rabbit muscle exhibited marked differences in certain physicochemical properties. These included pH stability, inactivation by thiol-group reagents, inhibition by alphaalpha-trehalose, methyl alpha-d-glucoside, sucrose, turanose, polyols, glucono-delta-lactone and monosaccharides, pH optimum and the kinetics and pH-dependence of cation activation. 2. The results are interpreted in terms of the existence of at least two specific substrate-binding sites or sub-sites. One site is specific for the binding of maltose and probably other oligosaccharides. The second site binds polysaccharides such as glycogen. 3. The sites appear to be in close proximity, since glycogen and maltose are mutually inhibitory substrates and interact directly in transglucosylation reactions. 4. Acid alpha-glucosidase exhibited intrinsic transglucosylase activity. The enzyme catalysed glucosyl-transfer reactions from [(14)C]maltose (donor substrate) to polysaccharides (glycogen and pullulan) and to maltose itself (disproportionation). The pH optimum was 5.1, with a shoulder or secondary activity peak at pH5.4. The glucose transferred to glycogen was attached by alpha-1,4- and alpha-1,6-linkages. Three major oligosaccharide products of enzyme action on maltose (disproportionation) were detected. 5. The kinetics of enzyme action on [(14)C]maltose showed that the rate of transglucosylation increased in a sigmoidal fashion as a function of substrate concentration, approximately in parallel with a decrease in the rate of glucose release. 6. The results are interpreted to imply competitive interaction at a specific binding site between maltose and water as glucosyl acceptors. 7. The results are discussed in terms of the possible existence of multiple subgroups of glycogen-storage disease type II.

Topics: Animals; Binding Sites; Carbon Isotopes; Glucose; Glucosidases; Glucosyltransferases; Glycogen; Glycogen Storage Disease; Glycoside Hydrolases; Heart Diseases; Humans; Hydrogen-Ion Concentration; Kinetics; Maltose; Muscles; Polysaccharides; Rabbits; Sulfhydryl Reagents; Water

Topics: Cardiomegaly; Electrocardiography; Electromyography; Female; Glucosidases; Glycogen; Glycogen Storage Disease; Heart; Heart Defects, Congenital; Heart Diseases; Heart Failure; Humans; Infant; Liver; Lymphocytes; Muscles; Myocardium; Radiography

Topics: Animals; Carbohydrates; Epinephrine; Glycogen; Heart Diseases; Histocytochemistry; Isoproterenol; Lysosomes; Male; Microscopy, Electron; Mitochondria; Myocardium; Myofibrils; Necrosis; Norepinephrine; Oxidoreductases; Phospholipids; Rats; Sarcoplasmic Reticulum

Topics: Adenosine Triphosphate; Altitude; Citric Acid Cycle; Glycogen; Heart Diseases; Humans; Hypoxia; Ischemia; Lactates; Muscles; Oxidative Phosphorylation; Oxygen Consumption; Physical Exertion; Pyruvates

Topics: Adenosine Triphosphatases; Alcohol Oxidoreductases; Autopsy; Death; Electron Transport Complex IV; Glucosyltransferases; Glycogen; Heart Diseases; Histocytochemistry; Humans; Hydrolases; Monoamine Oxidase; Myocardium; Succinate Dehydrogenase

Topics: Cardiomyopathies; Diagnosis, Differential; Glycogen; Heart Diseases; Histocytochemistry; Humans; Monoamine Oxidase; Myocardium; Pathology; Phosphorylases; Phosphotransferases; Rats; Research

Topics: Alcoholism; Animals; Cardiomyopathy, Alcoholic; Electrons; Endoplasmic Reticulum; Glycogen; Heart Diseases; Humans; Lipids; Lysosomes; Microscopy; Microscopy, Electron; Mitochondria; Myocardium; Myofibrils; Nerve Degeneration; Pathology

Topics: Angiocardiography; Autopsy; Blood Flow Velocity; Blood Pressure; Cardiac Catheterization; Electrocardiography; Endocardial Fibroelastosis; Glucagon; Glucose Tolerance Test; Glycogen; Glycogen Storage Disease; Heart Diseases; Hemoglobinometry; Humans; Infant; Metabolism; Oximetry; Radiography, Thoracic; Vectorcardiography

Topics: Coronary Disease; Electron Transport Complex IV; Electrons; Fluorescence; Glycogen; Heart Diseases; Histocytochemistry; Humans; Hypoxia; Isoproterenol; Lipids; Microscopy; Microscopy, Electron; Microscopy, Fluorescence; Mitochondria; Myocardial Infarction; Myocardium; Necrosis; Pathology; Rats; Research; Succinate Dehydrogenase

Topics: Alkaline Phosphatase; Blood Cells; Blood Chemical Analysis; Clinical Enzyme Tests; Glycogen; Heart Diseases; Heart Valve Diseases; Heart Valves; Humans; Lipids; Neutrophils; Oxidoreductases; Peroxidases

Topics: Cardiomyopathies; Disease; Glycogen; Glycogen Storage Disease; Heart Diseases; Heart Ventricles; Humans; Myocardium

Topics: Child; Glycogen; Glycogen Storage Disease; Glycogen Storage Disease Type II; Heart Diseases; Humans; Infant

Topics: Glycogen; Glycogen Storage Disease; Glycogen Storage Disease Type II; Heart; Heart Diseases; Humans

Topics: Child; Diabetes Mellitus; Female; Glycogen; Heart Diseases; Humans; Infant; Infant, Newborn; Infant, Newborn, Diseases; Metabolic Diseases; Mothers; Pregnancy