Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In Duchenne muscular dystrophy the activity of (Na+ + K+)ATPase in erythrocyte ghosts is reduced and its reaction to ouabain is paradoxical both in low sodium and high sodium systems. No such changes were seen in a case of Becker dystrophy, in limb-girdle dystrophy, and in neurogenic atrophy of muscles. In myotonic dystrophy and congenital myotonia the activity of ATPase and its inhibition by ouabain were depressed.
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PMID:Erythrocyte ghosts (Na+ + K+) ATPase activity in Duchenne's dystrophy and myotonia. 6 28

Active ion exchanges across erythrocyte membrane from patients with Duchenne muscular dystrophy were studied by two methods: --erythrocyte ghosts (Na+,K+)ATPase activity and its sensibility to ouabain, using an enzymatic method; --active sodium outflux and its sensibility to ouabain using a radioisotopic method. (Na+,K+)ATPase activity and active sodium outflux were decreased in dystrophic patients compared to normal sex- and age-matched controls. Enzymatic activity and active sodium outflux were inhibited by ouabain 10(-4) M in patients and in controls. Inhibition of the active sodium outflux was lower in patients than in controls. The results are discussed in light of the literature.
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PMID:The sodium pump of erythrocytes from patients with Duchenne muscular dystrophy: effect of ouabain on the active sodium flux and on (Na+, K+)ATPase. 7 65

The cation-stimulated adenosine triphosphatase (ATPase) activities of erythrocyte ghosts and erythrocyte ghost plasma membrane fragments of patients with Duchenne muscular dystrophy (DMD) were compared with activities in age-matched normal male controls. DMD Mg++-stimulated ATPase activity was within the normal range. The specific activity of DMD erythrocyte ghost Na+,K+-stimulated, Mg++-dependent ATPase was also normal, and was inhibited by 10(-4) M ouabain to an extent comparable with controls. Ca++-stimulated, Mg++-dependent ATPase activity of DMD erythrocyte ghost plasma membrane fragments, assayed at 0.5 mM free Ca++, was 21% above that in age-matched male controls (n = 22, 2-tailed paired t-test, P less than 0.01). Kinetic studies indicated that the DMD erythrocyte Ca++-stimulated, Mg++-dependent ATPase has greater affinity for MgATP than the enzyme in control erythrocytes.
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PMID:Erythrocyte cation-activated adenosine triphosphatases in Duchenne muscular dystrophy. 14 27

A defective membrane mechanism has been suggested [Arch. Neurol. 33, 315 (1976)] for the pathogenesis of Duchenne muscular dystrophy. The characteristic clinical and biological findings, including leakage of cellular enzymes into the serum in the disease, have been duplicated by the imipramine/serotonin rat myopathy model. Sarcolemma was prepared from quadriceps femoris muscles of control and myopathy-affected animals. The activities of sarcolemmal adenosinetriphosphatase and acetylcholinesterase were inhibited in vitro by imipramine and serotonin. The inhibition by imipramine of these sarcolemma-bound enzyme systems decreased the Vmax and increased the Km. This mixed type of inhibition is consistent with an imipramine-induced interference at these enzyme sites and a disruption of lipid-protein interrelations. We hypothesize that such conformational membrane changes might contribute to the leakage of macromolecules such as enzymes from the cell interior.
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PMID:Mechanisms of cellular enzyme release. II. Inhibition of sarcolemmal enzymes by myopathy-inducing agents. 14 73

The adenosine triphosphatase activity of erythrocyte ghosts from patients with Duchenne muscular dystrophy was inhibited by 10(-4) M ouabain to a smaller extent than in normals, when measured in the presence of either high or low concentrations of sodium or potassium ions. The inhibition by ouabain of the enzyme in normal ghosts, measured with low sodium or potassium ions, was less if the erythrocytes were first incubated with plasma from Duchenne patients than if incubated with normal plasma. Similar results were obtained when the ghosts themselves were incubated with Duchenne or normal plasma before assay.
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PMID:Effect of ouabain upon erythrocyte membrane adenosine triphosphatase in Duchenne muscular dystrophy. 14 73

The histochemical profile of individual human skeletal muscle fibres was analysed by correlating mitochondrial oxidative enzyme activity and that of myofibrillar ATPase at pH 9.5 and after pre-incubation at pH 4.3 and pH 4.6. In normal control muscle, only a small percentage of fibres did not conform to one or other of the normal variants of Type I and Type II fibres. In biopsies from early cases of Werdnig-Hoffmann disease, the denervated fibre populations contained many abnormal Type I and Type II fibres, including "IIc" fibres, but the basic distinction between Type I and Type II was preserved. However, in infantile spinal muscular atrophy patients aged two years and over, this distinction was progressively lost, leading to the total dedifferentiation of the atrophied fibres. In the Kugelberg-Welander form of spinal muscular atrophy, many of the constituent fibres of re-innervated groups displayed normal or near-normal histochemical profiles, but chronically denervated fibres became totally dedifferentiated. In Duchenne dystrophy, the spectrum of histochemical types appeared to be more continuous due to the emergence of fibres with properties intermediate between those of the normal variants, but the basic distinction between Type I and Type II fibres was preserved in the majority of cases. The percentage of severely abnormal fibres was higher in Type II than Type I and probably contributed to the observed decrease in the overall proportion of Type II fibres. Although very small atrophied fibres were observed in biopsies from cases of Becker and Duchenne dystrophy, these did not show the total dedifferentiation seen in the chronically denervated fibres in cases of spinal muscular atrophy.
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PMID:Patterns of abnormal histochemical fibre type differentitation in human muscle biopsies. 15 Apr 55

The purpose of this study was to determine whether the previously reported differences in adenylate cyclase activity between the sarcolemma of normal and dystrophic chick muscles are also found in the SR, to search for a possible relationship between the adenylate cyclase changes and the pathophysiology of dystrophy, and to investigate whether the findings can be extended to Duchenne human muscular dystrophy by studying the adenylate cyclase and ATPase activities of erythrocyte ghosts from DMD patients and carriers. Microsomes were separated by standard techniques from the pectoralis muscles of normal and dystrophic ckeckens of various ages. The microsomal yields were significantly larger in dystrophic muscles. Adenylate cyclase activities in dystrophic microsomes were higher than those in matched controls and increased with the progression of the disease. The ratio between the two rose from one at 2 weeks of age to nine at about 9--10 weeks. Kinetic analyses showed that the ks for MgATP2- was about 40 microM (at 3 mM Mg2+ and 0.3 mM Ca2+) both in normal and dystrophic microsomes, that calcium caused umcompetitive inhibition of the enzyme (Ki = 0.2 mM), that the effect of calcium was noncooperative (Hill coefficient, nH = 1), that calcium did not affect the cooperativity for MgATP2-, and that magnesium competitively removed the calcium inhibition and caused additional, cooperative stimulation of the enzymatic activity (ka = 1.5 mM; NH =2). The major difference between normal and dystrophic adenylate cyclase was a higher enzymatic velocity in the latter, suggesting a larger amount of enzyme. We investigated whether altered cAMP levels may effect calcium accumulation. Calcium uptake measured (in the presence of oxalate) at several ages revealed no difference between normal and dystrophic chickens. The extent of calcium binding was also similar, although the kd for Ca2+ was lower in dystrophic microsomes. Binding was enhanced in the presence of exogenous protein kinase, but the responses of normal and dystrophic tissues were similar. We concluded that the elevation of adenylate cyclase in dystrophy was not related to microsomal calcium accumultion. Ivestigation of the localization of microsomal adenylate cyclase supported this view. Separation of calcium-loaded microsomes on a discontinuous sucrose gradient into four fractions demonstrated that adenylate cyclase activity, measured in the presence of Lubrol-PX and EGTA, was inversely related to calcium-accumulating activity. Na+, K+-ATPase comigrated with adenylate cyclase. Highest specific activities were found in the lightest fraction. These observations were confirmed by histochemical studies. The reaction product from adenylate cyclase activity was present predominantly in the terminal cisternae of the SR. In the context of the literature, our findings suggest that the rises in adenylate cyclase and Na+, K+-ATPase in avian dystrophy are compensatory changes, elicited by a defect in ECC at the calcium release step...
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PMID:Adenylate cyclase in muscular dystrophy. 15 10

Basal adenylate cyclase activity was increased in red cell ghosts from both patients with Duchenne muscular dystrophy and their mothers when the activities were compared to proper age-matched controls. The activity of ATPase measured in the presence of Na+, K+, and Mg2+ was not found to be different in erythrocyte ghosts from Duchenne dystrophic patients, age-matched controls, or the mothers of Duchenne patients, and ouabain inhibited ATPase in ghosts to the same extent in all membrane preparations.
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PMID:Adenylate cyclase and ATPase activities in red cell membranes of patients and genetic carriers of Duchenne muscular dystrophy. 15 46

Some recently described abnormalities in the serum and red cell membranes in Duchenne dystrophy have been examined as methods of carrier detection in a single-blind controlled study. Twelve carriers (4 definite, 3 probable and 5 possible carriers previously found to have raised creatine kinase levels) and 12 normal female controls of the same age, were examined on 3 separate occasions at approximately two-weekly intervals. Analysis of age-dependent red cell shape changes, serum haemopexin levels, red cell K+ efflux rate, sensitivity of red cell ghost membrane ATPase to ouabain, membrane protein phosphorylation studies and lactate dehydrogenase isoenzyme profiles on agarose gel electrohoresis all failed to distinquish carriers from controls. The carriers suffered muscle cramps more frequently than the controls and all but one carrier and two control subjects were correctly identified by manual muscle strength testing, certain proximal muscles in paricular being consistently weaker in carriers than in the control group subjects. Scalar electrocardiography revealed higher values for the R/S ratio in Leads V1 and V2 and the sum (R-S) in V2.
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PMID:An evaluation of some carrier detection techniques in Duchenne muscular dystrophy. 16 Apr 46

Adenosine triphosphatase (ATPase) activity in erythrocyte membranes from patients with Duchenne dystrophy was inhibited by ouabain less than in normal individuals in assay systems containing high or low contents of salt. Epinephrine and cyclic adenosine monophosphate increased total ATPase activity in all samples, and epinephrine restored ouabain sensitivity to the Duchenne membranes. Basal adenyl cyclase activity in about twice that of controls. Epinephrine stimulated adenyl cyclase activity of normal membranes two to three times, but did not stimulate the enzyme in Duchenne membranes. These differences may reflect a genetic abnormality of the membrane.
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PMID:Biochemical abnormalities of erythrocyte membranes in Duchenne dystrophy. Adenosine triphosphatase and adenyl cyclase. 18 Sep 37


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