Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cardiac tissue obtained by left-ventricular endomyocardial biopsy from patients with valvular heart-disease was assayed for marker enzyme activities of subcellular organelles and these were correlated with left ventricular function as assessed by haemodynamic studies. In patients with poor left ventricular function, calcium-dependent adenosine-triphosphatase (A.T.P.ase) activity, predominantly localised to the myofibrils, was strikingly reduced. Activity of lactate dehydrongenase, a cytosol enzyme, was significantly increased in tissue from patients with poor left ventricular function. The activity of enzymes associated with sarcolemma (5'-nucleotidase), mitochondria (glutamate dehydrogenase and monoamine oxidase), microsomes (neutral alpha-glucosidase), and lysosomes (acid phosphatase, N-acetyl-beta-glucosaminidase) was no different in patients with good or poor left ventricular function. It is suggested that reduced myofibrillary A.T.P.ase concentration is the biochemical basis for the impaired ventricular function.
 ...
PMID:Enzymic analysis of cardiac biopsy material from patients with valvular heart-disease. 5 85

1. Homogenates of guinea-pig left ventricle were fractionated by differential pelleting and by centrifugation on continuous sucrose density gradients. 2. The principal subcellular organelles of myocardium, characterized by their marker enzyme content, were resolved by density gradient centrifugation in a small-volume zonal rotor. The equilibrium densities (p) of the principal organelles are (with marker enzymes in parentheses): sarcolemma, 1-12 (5'-nucleotidase); lysosomes, 1-16 (N-acetyl-beta-glucosaminidase); mitochondria, 1-17 (cytochrome oxidase); peroxisomes, 1-18 (catalase); cytosol (lactate dehydrogenase). 3. The subcellular distribution of various adenosine triphosphatase activities and previously unassigned enzymes was determined. Leucyl-beta-naphthylamidase and gamma-glutamyl transpeptidase showed both cytosol and sarcolemma components. Ca2+-dependent adenosine triphosphatase showed dual localization to the mitochondria and to the sarcolemma.
 ...
PMID:Analytical subcellular fractionation of guinea-pig myocardium. 14 54

The application of zonal centrifugation to the analysis of homogenates of cardiac and skeletal muscle permits selection of fractions that are enriched in markers for lysosomes, sarcolemma, sarcoplasmic reticulum, and mitochondria. The method of disruption of normal and pathological tissue alters significantly the distribution of total protein and peaks of enzymatic activity on the gradient. Total activities of cathepsin, N-acetyl-beta-glucosaminidase, beta-glucuronidase, and para-nitrophenylphosphatase are distributed at different concentrations of sucrose on the gradient. Beta-Glucuronidase appears to "mark" the sarcoplasmic reticulum, as well as lysosomes, of skeletal muscle, para-Nitrophenylphosphatase, a common marker of acid phosphatase of lysosomes, is enriched in those fractions of cardiac muscle containing the highest specific activity of ouabain-inhibited Na-K-ATPase. Thus, these two enzymes appear to have a localization in at least two separate organelles. On the other hand, these results may indicate the isolation of several "populations" of lysosomes that are associated constantly with distribution peaks of other organelles. In any event, attempts to correlate changes in structure of organelles of normal and pathological specimens of tissue with functional impairment, e.g., Ca2+ uptake, activity of Na-K-ATPase, etc., must include consideration of dual localization of enzymatic markers or cross contamination by populations of other organelles.
 ...
PMID:Lysosomes of cardiac and skeletal muscle: resolution by zonal centrifugation. 17 16

In order to ascertain the pathogenesis of myocardial cell vulnerability in spontaneously hypertensive rats (SHR), several enzyme activities were examined by using subcellular fractions of myocardium and compared to those in Wistar-Kyoto rats (WKY). In the normotensive WKY heart, both 5'-nucleotidase and Na+/K(+)-ATPase, which are plasma membrane associated enzymes, increased with age. But in the SHR heart, both enzymes were lower at 16 weeks than they were at 10 weeks of age. Moreover, at 16 weeks of age they were lower in SHR than in WKY. On the other hand, NADP(+)-isocitrate dehydrogenase activity, a mitochondria associated enzyme, was higher in SHR than in WKY at 6 weeks, but lower at 10 and again at 16 weeks of age. The activities of both acid phosphatase and N-acetyl-beta-glucosaminidase, which are lysosomal enzymes, decreased with age in SHR but not in WKY. These results suggest that an enzymatic alteration in the plasma membrane and mitochondria may be one of important factors behind myocardial vulnerability in the SHR heart.
 ...
PMID:Some enzyme characteristics of spontaneously hypertensive rats myocardium. 223 22

We have undertaken the analytical fractionation of epithelial cells from toad urinary bladder, a tissue extensively used to study epithelial transport of ions and water. In an attempt to establish markers for the main subcellular organelles, a number of enzymes were assayed in cell homogenates. The nearly ubiquitous plasma membrane marker 5'-nucleotidase, and the transferases that donate N-acetylglucosaminyl, galactosyl, and sialyl residues to glycoproteins and glycolipids in the Golgi complex were not detectable. Glucose-6-phosphatase activity was low in relation to that of nonspecific phosphatases and, therefore, not suitable for identifying the endoplasmic reticulum. Like the cytosolic enzyme lactate, dehydrogenase, catalase was essentially found in the high-speed supernatant, with a noteworthy part of aminopeptidase (substrate, leucyl-beta-naphthylamide) and NAD glycohydrolase. Other enzymes, including cytochrome c oxidase, acid phosphatase, acid N-acetyl-beta-glucosaminidase, alkaline phosphatase, alkaline phosphodiesterase I, nucleoside diphosphatase (substrate ADP), oligomycin-resistant Mg++-ATPase, and mannosyltransferase (acceptor, dolichylphosphate) were fairly active and largely sedimentable. After differential centrifugation, cytochrome oxidase, acid phosphatase, and acid N-acetyl-beta-glucosaminidase were typically associated with the large granule fraction, whereas the other sedimentable enzymes exhibited a broad distribution profile overlapping the nuclear, large granule, and microsome fractions. Their behavior in density equilibrium centrifugation is examined in a companion paper.
 ...
PMID:Subcellular fractionation of epithelial cells from toad urinary bladder. 1. Assay of marker enzymes and differential centrifugation. 250 71

Cytoplasmic granules obtained from toad urinary bladder epithelial cells were brought to buoyancy in a linear sucrose gradient. The gradient was loaded either with untreated cytoplasmic granules, or with granules treated with Na pyrophosphate (PPi), with digitonin, or with PPi and digitonin in succession. The following enzymes were assayed in the gradient subfractions: oligomycin-insensitive Mg++-ATPase, alkaline phosphodiesterase I, alkaline phosphatase, acid N-acetyl-beta-glucosaminidase, cytochrome oxidase, nucleoside diphosphatase (substrate, ADP), aminopeptidase (substrate, leucyl-beta-naphthylamide), and mannosyltransferase (acceptor, dolichylphosphate). Comparison of the density distributions of enzymes in untreated and treated preparations led to the characterization of 4 distinct subcellular entities. In agreement with the properties of mitochondria from other cell types, cytochrome oxidase buoys at 1.18 within a narrow density range and its behavior is not significantly altered by PPi or digitonin. Under all conditions, acid N-acetyl-beta-glucosaminidase is recovered over a broad density range in the lower part of the gradient and appears as a qualified lysosomal marker. Mg++-ATPase, alkaline phosphodiesterase I, and alkaline phosphatase belong to a group with the distinguishing features of a low equilibrium density in native cytoplasmic granules and a marked shift (+0.03 density units) after digitonin treatment. Such properties are typical of the plasma membranes. Part of the aminopeptidase activity probably also belongs to plasma membrane-derived elements. Minor differences between alkaline phosphatase and the other 2 members of that group make it possible that their distribution domains in the membrane do not overlap or coincide.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Subcellular fractionation of epithelial cells from toad urinary bladder. 2. Isopycnic centrifugation and effect of density perturbants. 255 74

The substituted benzimidazole, omeprazole, is a potent inhibitor of the ATP-dependent proton pump of the parietal cell. Since there is accumulating evidence that hepatic lysosomes also possess an ATP-dependent proton pump system to maintain internal acidification, and since antibodies to the putative lysosomal proton pump protein are immunologically similar to the parietal cell (H+ + K+) ATPase, we studied the effects in rats of six days of omeprazole treatment on hepatic lysosomal function. Omeprazole, 5 mg kg-1, a dose five times the ED50 for gastric acid secretion inhibition in rats, did not alter the activity of three representative lysosomal enzymes in liver (acid phosphatase, beta-galactosidase and N-acetyl-beta-glucosaminidase) nor did it alter lysosomal enzyme latency, a measure of the integrity of the lysosomal membrane. Furthermore, bile flow and the secretion of lysosomal enzymes into bile were also unaffected by omeprazole. These data indicate that in rats short-term treatment with omeprazole, in doses that markedly inhibit gastric acid secretion, has no major biological effect on liver lysosomal integrity and lysosomal enzyme activity.
 ...
PMID:Lack of effect of omeprazole, a potent inhibitor of gastric (H+ + K+) ATPase, on hepatic lysosomal integrity and enzyme activity. 287 Jan 66

Two-micrometer sections of methacrylate-embedded kidney were used to investigate the enzymatic activities of mouse kidney where the proximal tubule and Bowman's capsule from the same corpuscle were viewed in the same section. Alkaline phosphatase, acid phosphatase, 5'-nucleotidase, gamma-glutamyl transpeptidase, N-acetyl-beta-glucosaminidase, leucine aminopeptidase, alpha-naphthyl butyrate esterase, and adenosine triphosphatase activities were observed in the proximal tubule, but only 5'-nucleotidase, alpha-naphthyl butyrate esterase, and alkaline phosphatase were observed in the squamous portion of the parietal epithelium of Bowman's capsule. The use of methacrylate-embedded tissue allowed more precise localization of enzymatic activity than is possible with most frozen sections. This may provide interesting applications not only for characterization of kidney diseases but also for characterization of other normal and abnormal tissues.
 ...
PMID:Enzymatic histochemistry of mouse kidney in plastic. 288 Aug 90

Reversal of myocardial biochemical changes with insulin treatment (4 and 8 wk) was studied in 8 and 12 wk streptozotocin (STZ)-diabetic rats. STZ-induced diabetes was characterized by elevations in blood glucose, serum cholesterol, and triglycerides and depressed serum insulin levels. Insulin treatment for 4 and 8 wk completely restored the serum alterations to control values. The polyuria, polydipsia, and polyphagia were also markedly diminished by the insulin treatment. Diabetic rats had pronounced decreases in body, heart, and left ventricular weights, all of which were completely reversed by the insulin treatment. Hydroxyproline accumulation in diabetic rat hearts was only reversed by the 8-wk and not by the 4-wk insulin treatment. STZ produced a significant depletion of left ventricular magnesium content as well as depression of K+-stimulated sarcoplasmic reticulum and myofibrillar ATPase activities. Both the 4- and 8-wk insulin treatment produced a complete recovery of the myocardial magnesium content. No significant changes in sarcolemmal Na+-K+-ATPase and K+-stimulated p-nitrophenyl phosphatase activities were observed in diabetic animals compared with control. The decreased latency of the lysosomal hydrolase, N-acetyl-beta-glucosaminidase, and the increased collagen deposition observed in the diabetic hearts were only partially reversed by the 4-wk insulin treatment, but completely reversed by the 8-wk treatment period.
 ...
PMID:Insulin reversal of biochemical changes in hearts from diabetic rats. 294 95

Long-chain acylcarnitines are membrane-active intermediates of fatty acid metabolism whose intracellular accumulation has been implicated in the myocardial injury associated with both streptozotocin-induced diabetes and acute ischemia. In the present study, rats treated with streptozotocin (50 mg/kg i.v.) exhibited increases in myocardial long-chain acylcarnitines comparable to those previously reported to occur in moderate to severe ischemic injury. With the exception of a reduction in the sedimentable (lysosome-associated) fraction of myocardial N-acetyl-beta-glucosaminidase and a decrease in sarcoplasmic reticulum K+, Ca++-stimulated ATPase activity, other characteristic indices of myocardial ischemic damage, notably inhibition of sarcolemmal and mitochondrial ATPase activities as well as alterations in the ionic composition of myocardial tissue, were not apparent in the hearts of the streptozotocin-diabetic animals. On the basis of in vitro studies using palmitylcarnitine, it does not seem that differential sensitivity to long-chain acylcarnitine inactivation can explain the preferential inhibition of the sarcoplasmic reticulum ATPase enzyme observed in vivo. Our data are consistent with the findings of others suggesting that long-chain acylcarnitines are unlikely to be the most important or sole mediators of myocardial ischemic injury. However, a modulatory role of these substances in myocardial ischemic injury or in determining the increased susceptibility of diabetics to the complications of ischemic heart disease cannot be excluded at present.
 ...
PMID:Subcellular myocardial abnormalities in experimental diabetes: role of long-chain acylcarnitines. 294 27


1 2 Next >>