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

---

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

The autopsy report of an asymptomatic, non familial cardiomyopathy with widespread fatty infiltration of the right ventricular wall in two alcoholic subjects, who were also heavy smokers and suffering from a serious laryngeal obstruction, led the Authors to investigate, on the basis of a thorough review of the literature, the possibility that hypoxia, alcoholism and smoke could have caused the development of the cardiac lesion. The presence of myocardial fatty infiltration is explained, under conditions of high-flow hypoxia, by the reduced fatty acid oxidation. The higher tissue levels of fatty acyl-CoA, fatty acyl-carnitine and alpha-glycerophosphate thereby lead to the increased conversion of the FFA into tissue lipids. Under hypoxic conditions there is also an increased polyols synthesis. The reduced conversion of dyacylglycerol into phosphatidic acid causes its tissutal increase and the interaction with fatty acyl-CoA to produce triacylglycerol and CoASH. In alcoholic patients reduced oxidation and increased FFA synthesis is sustained by the altered mitochondrial respiratory control and excess of acetate, with the consequent increase in acetyl-CoA, fatty acyl-CoA and alpha-glycerophosphate concentration. In addition, fatty acid ethyl esters normally absent in the myocardium are formed. The fact that, in hypoxic or alcoholic subjects with cardiomyopathy, an impaired myocardial contractility has been noted as the most relevant haemodynamic factor may be explained by both the reduced energy production following the decrease in aerobic glycolysis and FFA oxidation, and specific genetic changes that lead to both the production of a myosin with lower Ca2 + ATPase activity and a reduced protein (and therefore myofibrillar) synthesis. This fact can result in a severe atrophy of the cardiac myocytes. The lower their contractile activity, the more evident the process of atrophy. The lesion principally affects the right ventricle for both metabolic and anatomical reasons. It has been shown how, under normal conditions, the RV metabolism is suited to a relatively reduced O2 supply situation, with a high lactate dehydrogenase and alpha-hydroxybutiratedehydrogenase activity. It is more likely to be affected therefore whenever there is a chronic state of high-flow hypoxia. While alpha-HBDH allows the RV extensive utilization of ketone bodies as an energy source, its notable increase under hypoxic conditions further increases the synthesis of fatty acids and therefore fatty infiltration of the myocardium. The relatively lower capacity for oxygen extraction and lower tissue perfusion of the RV compared with the left ventricle make an adequate oxygen supply in the case of increased O2 demand even more difficult.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Hypoxic right ventricular cardiomyopathy. A morphological and pathogenetic study on the myocardial atrophy and fatty infiltration. 209 33

Reactive oxygen species are noxious to gastrointestinal mucosa and contribute to a variety of gastrointestinal diseases. We examined whether 16.16 dimethyl prostaglandin E2 (PG) is protective against the oxidizing action of 6% H2O2 causing gross hemorrhagic lesions in rat gastric mucosa. Male Wistar rats were treated with PG, 0.005-5 micrograms/kg, either intragastrically (i.g.) or subcutaneously, 30 min prior to i.g. administration of 6% H2O2, 0.5 ml/100 g. Further animals received 25 mg of the mucus dissolvent N-acetyl-cystein (NAC) following oral PG treatment or 30 mumol/kg of the H+K(+)-ATPase inhibitor BY 831-78 (BY), 4 h before onset of the experiments. Volume, pH and beta-N-acetyl-glucosaminidase and lactate dehydrogenase as parameters of cell damage were determined in the gastric juice. i.g. PG treatment achieved 60 and 55% reduction of the mucosal lesions in doses between 5 and 0.05 micrograms/kg, respectively. i.p. PG administration was effective in all doses tested. Gastric juice volume was only slightly and enzymes were not significantly affected by PG treatment. NAC did not diminish PG efficacy or aggravate mucosal lesions. Gastric acid suppression did not increase PG-induced protection but was strongly protective by itself, reducing damage by 75%. Low-dose PG treatment achieves an effective protection against oxidative damage in gastric mucosa, which is not the result of dilution or enhanced mucus production.
...
PMID:Effect of 16.16 dimethyl prostaglandin E2, N-acetyl-cysteine and the proton pump inhibitor BY 831-78 on hydrogen peroxide-induced mucosal damage in the rat stomach. 214 65

In a previous study we compared the effects of patulin (PAT) and ouabain, a specific inhibitor of the Na(+)-K+ ATPase, and found significant differences with regard to the kinetics of Na+ influx and K+ efflux, and sulfhydryl reactivity in LLC-PK1 cells. The purpose of the present study was to determine the relationship between Na+ influx, K+ efflux, membrane potential ([3H]tetraphenylphosphonium accumulation), cellular viability [lactate dehydrogenase (LDH) release], and changes in cell morphology (blebs). The effects of PAT are concentration and time dependent. At concentrations of PAT above 10 microM there is a transient increase in intracellular electronegativity (less than 1 hr) followed by a sustained depolarization (greater than 1 hr) which is correlated with complete Na+ influx, K+ efflux, total LDH release, and bleb formation. However, at PAT concentrations of 5-10 microM there is a sustained increased intracellular electronegativity (4-8 hr) which is associated with partial Na+ influx and K+ efflux, no significant LDH release, and relatively few blebs. The hyperpolarizing effect may be a result of increased permeability to K+ relative to Na+. At times and concentrations which result in increased intracellular electronegativity, PAT has no effect on [3H]ouabain binding and thus increased Na+/K+ pump turnover does not seem to be the cause of the transient hyperpolarizing effect of PAT. These results are consistent with the hypothesis that PAT causes alterations in plasma membrane permeability which favor K+ efflux relative to Na+ influx. The toxic effects of PAT are irreversible in LLC-PK1 cells after even short pretreatment with PAT. The primary toxic lesion appears to be at some level other than that involving inhibition of macromolecular synthesis, perhaps the plasma membrane itself.
...
PMID:Chronology of patulin-induced alterations in membrane function of cultured renal cells, LLC-PK. 215 17

The half maximal inhibitory concentrations (IC50) of substituted benzimidazoles for the H+, K(+)-ATPase in hog gastric vesicles were measured by using the pyruvate kinase-lactate dehydrogenase-linked system in which hydrolysis of ATP was coupled with the oxidation of NADH. The vesicles were incubated in a solution containing a high concentration of KCl, valinomycin and Mg-ATP, and the intravesicular medium was acidified. The inhibitor was activated in the acidic medium and reacted with SH groups on the luminal (intravesicular) side of the ATPase. The active compound formed in the extravesicular medium (pH 6.11) was quenched by GSH. Under these conditions, IC50 of new compound E3810, 2[(4-(3-methoxypropoxy)-3-methylpyridine-2-yl)methyl-sulfinyl]-1H- benzimidazole sodium salt, was 0.072 microM and that of omeprazole was 0.47 microM at 25 degrees. On the other hand, the rates of formation of active compounds, tetracyclic sulfenamide derivatives, from original substituted benzimidazoles in 0.1 N HCl (k) were determined by measuring optical density at the characteristic wavelengths of the active compounds. There was a good correlation between IC50 and k for various substituted benzimidazoles including E3810, methoxy derivative of E3810, omeprazole, Ro 18-5364, H compound, picoprazole and timoprazole. This fact suggest that the rate of the formation of the acid-activated compound is a main factor determining the potency of the inhibitor.
...
PMID:The potency of substituted benzimidazoles such as E3810, omeprazole, Ro 18-5364 to inhibit gastric H+, K(+)-ATPase is correlatedwith the rate of acid-activation of the inhibitor. 215 89

Hexokinase, lactate dehydrogenase, acylphosphatase, (Na+,K+)-ATPase and Ca2(+)-ATPase of selected areas from postmortem Alzheimer's disease brains were studied. Hexokinase and lactate dehydrogenase were significantly changed in all the examined subcortical nuclei. (Na+,K+)-ATPase activity was altered in several areas of Alzheimer's disease brains. No changes in Ca2(+)-ATPase and acylphosphatase were observed. The main alterations of the assayed enzymes were observed in subcortical areas but not in cortical areas of Alzheimer's disease brains.
...
PMID:Changes in Na+,K(+)-ATPase, Ca2(+)-ATPase and some soluble enzymes related to energy metabolism in brains of patients with Alzheimer's disease. 216 43

Merocyanine 540 (MC 540) is a photosensitizing dye that is used clinically for the purging of autologous bone marrow grafts and preclinically for the inactivation of enveloped viruses in blood products. Its mechanism of action is not yet well understood. This paper investigates the sites of MC 540-mediated photodamages in L1210 leukemia cells by examining the effects of MC 540-sensitized photoirradiation on several soluble and membrane-bound marker enzymes. When exposed to MC 540 and white light under a standard set of conditions, the activities of Na+/K(+)-ATPase, Mg2(+)-ATPase, and 5'-nucleotidase (three plasma membrane-bound enzymes) were reduced by 54, 49, and 55%, respectively. None of the intracellular enzymes included in this survey was affected by MC 540-sensitized photoirradiation as long as the plasma membrane remained intact. The two soluble enzymes, lactate dehydrogenase and malate dehydrogenase, remained refractory to MC 540-sensitized photoirradiation even after the plasma membrane had been disrupted. By contrast, the activities of the membrane-bound enzymes, NADPH-cytochrome c reductase and succinate dehydrogenase, were reduced in cell lysates by 55 and 81%, respectively. Purified NADPH-cytochrome c reductase was about 3 times less sensitive than the microsomal enzyme, suggesting that the membrane environment facilitated photoinactivation. The MC 540-sensitized photoinactivation of enzymes was accelerated in the presence of deuterium oxide and inhibited if oxygen in the medium was displaced by nitrogen or azide was added to the medium. Taken together, these data support the view that the plasma membrane is a major target of MC 540-mediated photodamages, that the inactivation of membrane-bound enzymes is an oxidative process, and that at least some photodynamic damages are mediated by type II chemistry.
...
PMID:Merocyanine 540-sensitized photoinactivation of soluble and membrane-bound enzymes in L1210 leukemia cells. 217 31

A case of mitochondrial encephalomyopathy with a partial cytochrome c oxidase deficiency was reported with special reference to electrophysiological studies. A 56-year-old man was readmitted to Himeji Central Hospital due to mental deterioration and character change. At the age of 44 when he was attacked by his first epileptic seizure, he was admitted to Himeji Central Hospital, where EEG abnormalities and cerebral atrophy were found. Anticonvulsants helped to relieve his generalized convulsions but the EEG abnormalities persisted. At age 46, he had the second generalized seizure, so he quit his job as a crane operator. His family began to notice deterioration of his intellectual function and hyperaggressive behavior. His daily activities, intellectual performance and mental condition gradually deteriorated (WAIS FIQ less than 60). Other clinical and laboratory findings are as follows: bilateral impaired hearing, no optic nerve atrophy, no disturbance of extra ocular muscle movements, mild wasting and weakness of his extremities, normal coordination and sensation, no myoclonus or other involuntary movements, normal laboratory data of serum creatinine kinase, lactate dehydrogenase and aldolase, and increased amount of lactate and pyruvate in serum and cerebrospinal fluid (CSF), no abnormal amino acids in urine. A biopsy specimen of right biceps brachii muscle revealed numerous ragged-red fibers in frozen sections stained by the Gomori trichrome method. These fibers did not react to a cytochrome c oxidase staining. An ATPase staining demonstrated an atrophy of type-2 fibers. An electron micrograph showed many mitochondria in the sarcoplasm but few paracrystalline inclusions. A biochemical analysis of the muscle biopsy also revealed a significant decrease in the cytochrome c oxidase activity.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:[A mitochondrial encephalomyopathy due to partial cytochrome c oxidase deficiency with giant evoked potentials--a case report]. 217 89

The ciliary muscle of the primate eye was stained histochemically with enzymes used to differentiate fiber types in the skeletal muscle. Differences between the outer meridional section and the rest of the muscle were found with all enzymes. Staining for myosin-ATPase with acid and alkaline preincubation, as well as for lactate dehydrogenase (LDH), resulted in a stronger reaction in the meridional section, while the reticular and circular portions showed minor activities. In contrast, succinate dehydrogenase (SDH) revealed a stronger activity in the reticular and circular muscle cells. Ultrastructurally, the meridional muscle cells contained fewer mitochondria, but more myofibrils in the cytoplasm, while circular and reticular muscle cells showed just the opposite. Therefore, the cells of the meridional ciliary muscle section resemble in some respects the rapid type-II skeletal muscle fibers, and the circular und reticular muscle cells are comparable to the slow type-I fibers of the skeletal muscle.
...
PMID:[Structural differences in the structure of the ciliary muscles in eyes of primates. A histochemical and morphological study]. 221 May 68

The biceps femoris muscle was surgically incised and sutured in 10 clinically healthy mongrel dogs, aged 1-2 yr and weighing 10-15 kg. The surgical wounds of 5 dogs were exposed to shortwave diathermy for 5 min daily for 7 days, starting a day after the creation of trauma. The remaining 5 dogs served as control. After 15 days of healing, the tissues from biceps femoris muscle were collected and subjected to histomorphological and histochemical examination. Mature collagen bundles were seen at healing site in diathermy treated animals while there were immature collagen fibres and more number of fibroblasts in control animals. Normal muscle fibres could be seen on either side of the healing tissue in treated animals whereas in control animals, atrophied and necrosed muscle fibres were encountered. The neutral and acid mucopolysaccharides, lipid droplets in the intermyofibrillar area and the activity of alkaline phosphatase, adenosine triphosphatase and lactate dehydrogenase at the healing site was better in treated as compared to controls.
...
PMID:Histomorphochemical effects of shortwave diathermy on healing of experimental muscular injury in dogs. 225 71

While the molecular mechanism underlying triethyllead (TEL) neurotoxicity is unknown, we hypothesize that triethyllead mediates an accelerated Cl-/OH exchange across neuronal membranes leading to prolonged depolarization and neuronal cell injury. As a test of this hypothesis we have investigated the effect of external ion modulation on triethyllead neurotoxicity in cerebellar granule cell culture. Cultures were prepared from neonatal rats and used 10-20 days in vitro. Cytotoxicity was assessed by lactate dehydrogenase (LDH) release and trypan blue exclusion. A slow, dose-dependent (1-30 microM TEL) release of LDH occurred after a variable latent period dependent upon [TEL]. External replacement of [Cl-]e by Na isothionate dramatically shifted the dose response curve to the left reflecting an accelerated stimulation of LDH release, while replacement of extracellular [Na+]e with equimolar choline chloride had a minimal protective effect. Similarly, high [Mg2+]e or low [Ca2+]e did not protect or potentiate TEL cytotoxicity. The low [Cl-]e accelerated TEL cytotoxicity was dependent on medium pH: alkaline pH potentiated the cytotoxicity. Low [Cl-]e had no significant effect on culture ATP over 5 hrs. ATP reduction was markedly stimulated by TEL in low Cl- medium in contrast to the minimal decline in [ATP] in the control medium. The reduction of ATP in the low [Cl-]e medium occurred prior to LDH or trypan blue staining release confirming that such reduction in [ATP] was not secondary to cell damage. Substituting K sulfate or Na sulfate for the Cl(-)-free medium revealed marked loss of ATP without LDH release in control and TEL supplemented cultures. These observations provide supporting evidence for the role of an abnormal Cl- flux in mediating TEL-induced neurotoxic injury. Specifically, the membrane depolarization is proportional to the gradient imposed by Cl- efflux/OH influx, stimulated by low [Cl-]e. The rapid loss in ATP appeared early, was not a secondary reflection of neuronal damage but a result of a combination of increased ion flux at the plasma membrane, stimulation of Na+/K+ ATPase and direct TEL-induced inhibition of mitochondrial oxidative phosphorylation.
...
PMID:Ionic modulation of triethyllead neurotoxicity in cerebellar granule cell culture. 228 48


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---