Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

(1) The histochemical staining pattern of succinic dehydrogenase (SDH) does not show unequivocal differentiation between the type I red and type II red fibres in mammalian striated muscles. (2) Since high biochemical activity of beta-hydroxybutyric dehydrogenase (beta-HOBDH) occurs in mitochondria of the type I red fibres, the histochemical localization of this enzyme may show a pattern of staining reciprocal to that seen for myofibrillar ATPase. (3) It remains to be confirmed that the type I red fibres, which are possibly slow-twitch physiologically, possess the highest concentration of myoglobin. The histochemical correlation of myoglobin and myofibrillar ATPase in serial sections should be studied. (4) In order to achieve a more realistic picture, various glycolytic and glycogenolytic enzymes should be incubated according to the gelatin film technique, or semipermeable membrane technique or collagen polypeptide technique. A histochemical correlation of phosphorylase, LDH, PFK, alpha-glycerophosphate dehydrogenase, and myofibrillar ATPase in adjacent muscle sections may throw light on the histochemical characteristics of the different fibre-types. (5) The specific histochemical demonstration of AMPase is achieved following preincubation of tissue sections. (6) ADPase has been demonstrated by the calcium precipitation technique only (GUTH and YELLIN, 1971). A number of studies claim, however, that ADPase is not demonstrable histochemically in muscle fibres. (7) The presence of magnesium ions is a prerequisite for the adequate histochemical demonstration of mitochondrial ATPase. The latter is inhibited almost completely by 40 mM Ca++ (when Mg++ is not added) at both neutral and alkaline pH values. (8) The histochemical activity of SR-AT-Pase seen as continuous reticula but without punctuate and sub-sarcolemmal staining possibly represents the extra ATPase of SR. (9) On the basis of myofibrillar ATPase reaction, an inherent heterogeneity, between the type II red and type II white may be recognized. In addition, the above fibre-types possess their respective sub-populations. (10) Following diK+ EDTA preincubation, some type II red fibres show selective lability. These are the mitochondria-rich fibres. Thus in the total absence of both punctuate and subsarcolemmal staining, the presence of mitochondrial ATPase activity under the histochemical conditions for myofibrillar ATPase is unlikely. (11) The reaction pattern of CK/ATPase (coupled reaction) at pH 6.9 is distinctly intermyofibrillar and unlike SDH-pattern. This reticular reaction is associated mainly with the SR and hence the importance of transphosphorylation in this organelle for the Ca++ uptake and muscle relaxation. (12) The CK/ATPase reaction at pH8.0 has shown important histoenzymatic characteristics. At this pH value the type I red fibres and slow-twitch soleus show myofibrillar reaction pattern. This identical histochemical behaviour suggests that type I red fibres are possibly slow-contracting...
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PMID:Histochemical characteristics of vertebrate striated muscle: a review. 18 61

This communication presents the results obtained in tubular aggregates of 24 enzyme histochemical techniques for demonstrating activity of oxidoreductases, transferases, hydrolases and isomerases. The activity characteristics of the tubular aggregates in m. gluteus medius of 18 patients with diseases of the neuromuscular system were almost identical. A high activity of the mitochondrial enzymes, NADPH: tetrazolium oxidoreductase, NADH:tetrazolium oxidoreductase and cytochrome c oxidase, could be shown in the pathological structures, whereas the activity of the mitochondrial enzymes, glycerol-3-phosphate:menadione oxidoreductase, succinate:PMS oxidoreductase, malate:NAD+ oxidoreductase and isocitrate:NAD+ oxidoreductase, and the partial mitochondrial enzymes, malate:NADP+ oxidoreductase and isocitrate:NADP+ oxidoreductase, was very slight or even absent. There was a moderate to strong activity of the glycolytic enzymes lactate:NAD+ oxidoreductase, glyceraldehyde-3-phosphate:NAD+ oxidoreductase, phosphofructokinase, phosphoglucomutase and glucose phosphate isomerase. In contrast, the activity of alpha-glucan phosphorylase was slight. The activity of phosphogluconate:NADP+ oxidoreductase, glucose-6-phosphate:NADP+ oxidoreductase and 5'-nucleotidase was slight, whereas there was no activity of myosin ATPase and mitochondrial ATPase, acid phosphatase or alkaline phosphatase. The high activity of AMP-deaminase was very striking. The activity of peroxidase was moderate. Results obtained with adsorption studies point to adsorption of some of the enzymes studied to the tubular aggregates in vivo and this phenomenon very probably determined the histochemical characteristics of these structures.
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PMID:Histochemical features of tubular aggregates in diseased human skeletal muscle fibres. 317 98

The purpose of this study was to determine whether myocardial adenosine triphosphatase (ATPase) activities were reduced in pigs with naturally occurring hypertrophic cardiomyopathy (HCM). The selection of hearts for the HCM and the normal control groups depended on histological examination. Specific ATPase activity and 5'-nucleotidase activity were measured in left ventricular myocardium obtained from HCM (n = 7) and normal control (n = 7) animals. The histological features of HCM included marked disorientation of muscle cells, thickening of the intramural coronary arterial wall with a narrowed lumen, endocardial fibrosis and myocardial fibrosis. The HCM group showed significant increases in both heart weight (32%) and heart weight to body weight ratio (46%). The total ATPase activity in crude homogenates from the HCM group was significantly decreased by 16%. Azide-sensitive ATPase (mitochondrial ATPase) activity, ouabain-sensitive ATPase (Na+, K+-ATPase) activity, basal Mg(2+)-ATPase activity and Ca(2+)-ATPase activity were all significantly decreased by 18%, 30%, 20% and 50%, respectively. In contrast, no significant decrease was found in the mean values for 5'-nucleotidase activity. These results suggest that myocardial ATPase activities are suppressed in pigs with naturally occurring HCM.
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PMID:Altered adenosine triphosphatase activities in pigs with naturally occurring hypertrophic cardiomyopathy. 764 94

Extracellular nucleotides interact with specific receptors on the cell surface and are locally metabolized by ecto-nucleotidases. Biochemical characterization of the ATPase and ADPase activities detected in rat heart sarcolemma, under conditions where mitochondrial ATPase and adenylate kinase were blocked, supports our proposal that both activities correspond to a single enzyme, known as ATP-diphosphohydrolase or apyrase. The physiological function of this enzyme could be dephosphorylation of the nucleotides present in the interstitial heart compartment acting together with 5'-nucleotidase. Both hydrolytic activities have similarities in: sarcolemma localization, bivalent metal ion dependence, optimum pH, effect of several amino acid residue modifiers, competitive inhibition of nucleotide analogs, and broad nucleoside di-and triphosphate specificity. The ATPase activity could not be separated from the ADPase either through isoelectrofocusing or electrophoresis under acid conditions.
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PMID:ATP-diphosphophydrolase activity in rat heart tissue. 886 7

Preconditioning is an effective mean of protecting the heart against prolonged ischemia by pretreating it with a minor insult, and the present paper reviews various controversies in this highly active field of research. In many models, adenosine plays a role by triggering the activation of protein kinase C. It may work in conjunction with other agents, such as bradykinin, but the putative role of noradrenaline is uncertain. Regulation of the enzyme producing adenosine (i.e., 5'-nucleotidase) has been reported during preconditioning but, because its activity does not seem to be associated with infarct size, it is unlikely that the hydrolase plays a pivotal role. Controversial data have been published on the involvement of mitochondrial ATPase, which may be ascribed to the poor time resolution of the experiments described; however, we do not believe that either acidosis or tissue ATP are important factors in triggering preconditioning. The role of glycolysis in the preconditioning effect remains to be firmly established; opposite mechanisms are activated in low-flow and stop-flow protocols. Although species differences regarding preconditioning exist, they seem to be more of a quantitative than a qualitative nature. The phenomenon could be clinically relevant because evidence is accumulating that preconditioning may take place during bypass surgery and coronary angioplasty if longer balloon-occlusion times are used.
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PMID:Controversies in preconditioning. 911 Jan 21