Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Monoclonal antibody PM4A2B was prepared by immunizing mice with calmodulin affinity purified Ca2+-Mg2+-adenosine triphosphatase from rabbit erythrocytes and screening the clones with a plasma membrane-enriched fraction (F1) from rabbit stomach smooth muscle. On Western blots, PM4A2B reacted with F1 and with ghosts, right-side-out vesicles, and inside-out vesicles prepared from erythrocytes giving one major band at 130 kDa and minor lower molecular weight bands whose intensity increased on freezing and thawing the membranes. On enzyme-linked immunosorbent assay, PM4A2B reacted with inside-out vesicles, but not with the right-side-out vesicles or ghosts prepared from erythrocytes. It activated the ATP-dependent Ca2+ uptake by F1 and by the inside-out vesicles prepared from the erythrocytes. PM4A2B should be useful in determining membrane sidedness as well as in investigating the mechanism of the sarcolemmal Ca2+ pump.
J Biol Chem 1988 Dec 25
PMID:Monoclonal antibody against an epitope on the cytoplasmic aspect of the plasma membrane calcium pump. 246 40

This study examined effects of extracellular magnesium (Mg++0) on the positive inotropic and toxic actions of cardiotonic steroids in cardiac muscle isolated from guinea pig heart. Increasing concentrations of Mg++0 produced a negative inotropic effect in electrically paced, left atrial muscle and decreased the sensitivity to arrhythmogenic actions of digoxin without affecting the maximum developed tension observed before dysrhythmic activity. Other signs of toxicity such as contracture were less sensitive to the antagonistic effects of Mg++0. Estimates of fractional occupancy suggested that the increased tolerance to digoxin-induced arrhythmias was mediated by an altered responsiveness to given levels of receptor binding. Experiments in partially purified membrane preparations demonstrated that elevations in Mg++ increased affinity for [3H]ouabain without affecting binding site density. Na+,K+-adenosine triphosphatase activity in these membrane preparations was also enhanced by Mg++; however, increases in buffer Mg++ concentration had no effect on the Na+-pump in intact tissue. In summary, these results indicate that elevations in Mg++0 act directly on myocardium to diminish the sensitivity to cardiotonic steroid-induced arrhythmias. Furthermore, data suggest that this antagonistic action of Mg++0 is not mediated by alterations in receptor binding or Na+-pump reserve capacity.
J Pharmacol Exp Ther 1989 Dec
PMID:Extracellular magnesium and cardiotonic steroid toxicity in isolated myocardial preparations. 253 49

Fischer F344 rats were given a cyclical diet of 0.06% 2-acetylaminofluorene (AAF), which progressively induced oval cell proliferation, cirrhosis and hyperplastic (or neoplastic) nodules. Primary liver tumours developed from 7 months after ceasing the diet. Liver samples taken during and after AAF administration and specimens of primary tumours were processed into frozen sections and examined microscopically for morphological changes in cell populations, stained histochemically for gamma-glutamyl transpeptidase (GGTase) and four phosphatases, and stained by the immunoperoxidase technique for the presence of antigens detected by seven anti-liver cell monoclonal antibodies and monoclonal antibodies to six oncoproteins. During and after AAF treatment several of the anti-liver antibodies revealed foci of aberrantly or heterogeneously-stained cells, although anti-oncoprotein antibodies showed no consistent changes. Foci of cells positive for GGTase and heterogeneous for adenosine triphosphatase (ATPase) were also seen. Nodules invariably showed heterogeneous antigenicity, raised GGTase and abnormal ATPase expression. Primary tumours exhibited varying degrees of positivity, negativity and heterogeneity with the anti-liver monoclonal antibodies, and all were positive for GGTase. Comparison between various parameters and different lesions showed the greatest concordance between nodules and tumours, suggesting that nodules are probably the precursors of malignant tumours in this system.
Br J Exp Pathol 1989 Dec
PMID:Heterogeneity of hepatocyte antigen expression in rat liver carcinogenesis: concordance between neoplastic nodules and tumours. 253 34

Myosin light chain 1 slow (LC1slow) was purified from the bovine slow-twitch muscle masseter and used as an antigen in chicken. The antibody fraction from egg yolk was employed to show the distribution of LC1slow in samples of diverse bovine muscles. Adjacent cryosections were cut. One section was stained for myofibrillar adenosine triphosphatase (ATPase) activity and the other was challenged with the antibody fraction, followed by a fluorescently-labelled secondary antibody. The ATPase section (viewed with conventional optical microscopy) displayed fast and slow fibres, whereas the antibody-labelled section (viewed with epifluorescent optics) showed which of the slow fibres contained LC1slow. In some of the muscles examined, the slow fibres contained variable amounts of LC1slow. In other muscles, such as those involved in chewing, the slow fibres were all rich in LC1slow. Slow fibres in yet other muscles, for example deep hip muscles and an extraocular muscle, were devoid of LC1slow. Based on the probable functions of the muscles examined, the hypothesis is advanced that LC1slow is associated with movement, its absence from slow fibres signifying a postural role for those slow fibres. The present work also documents the LC1slow content and muscle fibre composition of 14 hind leg muscles of a single ox. The results suggest postural and locomotory roles for certain muscles.
J Muscle Res Cell Motil 1989 Dec
PMID:A possible role for myosin light chain 1 slow of bovine muscle. 253 19

The effect of vitamin A deficiency on the intestinal absorption of nutrients and the activities of brush border enzymes were studied in albino rats. Intestinal uptakes of D-glucose, L-methionine, L-tryptophan and L-histidine were significantly greater in vitamin A-deficient animals than in controls. The specific activities of total adenosine triphosphatase (ATPase), ouabain-sensitive ATPase, maltase and sucrase in the intestinal mucosa of vitamin A-deprived rats were 121, 124, 131 and 134 per cent respectively, of the corresponding values in control animals. The DNA content of the small intestine in vitamin A-deficient rats was 36.5 per cent lower than in control rats. The stimulation in digestive and absorptive capacity appears to be an adaptive change in vitamin A-deficiency which decreases the intestinal cell population.
Indian J Med Res 1989 Dec
PMID:Effect of vitamin A deficiency on rat intestinal digestive & absorptive functions. 253 19

The effects of leukotrienes (LTs) B4, C4, and D4 on acid production by enriched (80%-85%) rat parietal cells were investigated. Acid production was indirectly measured by [14C]aminopyrine uptake into the cells. Leukotriene B4 (10(-10)-10(-6) mol/L) had no effect on basal or prestimulated [14C]aminopyrine uptake. Leukotriene C4 and LTD4 (10(-10)-10(-6) mol/L) also did not change basal acid production but potentiated prestimulated [14C]aminopyrine uptake. Maximal effects were observed with 1 x 10(-7) mol/L LTC4 or with 3 x 10(-7) mol/L LTD4. At these concentrations LTC4 and LTD4 induced the indicated increases above the responses to the following prestimulants (= 100%): 10(-4) mol/L histamine (71% and 74%, respectively), 10(-5) mol/L forskolin (54% and 106%), 10(-4) mol/L dibutyryl cyclic adenosine monophosphate (34% and 81%), and 10(-4) mol/L carbamylcholine (160% and 116%). Yet, adenosine triphosphate (2.5-5 x 10(-3) mol/L)-induced [14C]aminopyrine uptake in digitonin-permeabilized parietal cells was not further increased by LTC4 or LTD4. At 10(-5) mol/L the selective LTD4 antagonist L-660,711 (MK-571) reduced the effect of 3 x 10(-7) mol/L LTD4 by 74% but had no effect on the potentiation by LTC4. We conclude that the sulfidopeptide LTs C4 and D4, but not LTB4, exert a direct effect on rat parietal cells, and that this effect seems to be mediated by separate specific receptors. Leukotriene C4 and LTD4 potentiate prestimulated H+ formation by interacting with an intracellular mechanism that is commonly activated upon occupation of histamine H2- as well as muscarinic receptors, and that is also activated by the postreceptor stimuli forskolin and dibutyryl cyclic adenosine monophosphate; yet, this mechanism seems to be localized proximal to the H+,K+-adenosine triphosphatase.
Gastroenterology 1989 Dec
PMID:Leukotrienes C4 and D4 potentiate acid production by isolated rat parietal cells. 255 44

1. A circulating ouabain-like factor which inhibits the Na+,K(+)-pump has been implicated in volume-expanded states. To assess the role of this putative factor in normovolaemic rats, we measured erythrocyte and renal Na+,K(+)-adenosine triphosphatase activity after the infusion of a mixture of high-affinity digoxin-binding Fab fragments (Digibind) capable of removing digoxin from pump sites. 2. Compared with either saline (vehicle) or sheep immunoglobin G, infusion of the antidigoxin antibody caused a moderate increase of Na+,K(+)-adenosine triphosphatase activity in the erythrocyte (saline 348 +/- 12; immunoglobulin G 339 +/- 16; antidigoxin antibody 432 +/- 22 nmol h-1 mg-1; P less than 0.005 by analysis of variance) and a larger increase in the renal cortex (saline 9.7 +/- 0.9; immunoglobulin G 9 +/- 1.4; antidigoxin antibody 24.3 +/- 1.8 mumol h-1 mg-1; P less than 0.0005 by analysis of variance) without a change in blood pressure. 3. These results are consistent with the presence of a digoxin-like inhibitor of the Na+,K+-pump in normal rats.
Clin Sci (Lond) 1989 Dec
PMID:Stimulation of erythrocyte and renal Na+,K+-adenosine triphosphatase activity by antidigoxin antibody in normal rats. 255

The Na,K-adenosine triphosphatase (ATPase) alpha 2 subunit gene was found to display restriction fragment length polymorphisms (RFLPs) between the genomes of normotensive and hypertensive rats when digested with the restriction enzymes Bgl II and Hind III. In normotensive rats, we tested the spontaneously hypertensive rat (SHR) and its substrain, the stroke-prone spontaneously hypertensive rat (SHR-SP). Rat (SD) complementary (c) DNA encoding the alpha 2 subunit of Na,K-ATPase was used as a probe. When the probe was dissected these RFLPs were found to occur in the vicinity of the genomic locus encoding the middle part of the messenger (m) RNA for the alpha 2 subunit of Na,K-ATPase. A Northern blot analysis indicated that these RFLPs did not influence the alpha 2 subunit with regard to either size or amount of mRNA.
J Hypertens 1989 Dec
PMID:The Na,K-ATPase alpha 2 subunit gene displays restriction fragment length polymorphisms between the genomes of normotensive and hypertensive rats. 257 29

Calcium-activated myosin adenosine triphosphatase (ATPase) activity has been measured in sections of rat ventricles that were rapidly frozen to preserve the structure and regulatory state of myosin occurring in vivo. These results were related to myosin isozyme composition measured in ventricles by native gel electrophoresis and by quantitative immunocytochemistry. Both total ATPase activity and percent alpha-heavy chain rapidly rise during the first month following birth. However, ATPase activity remains constant at a high level from 1 to 12 months following birth, even though percent alpha-heavy chain declines during this period. The ATPase activity of V1 myosin was specifically determined using sections in which V3 myosin had been completely inhibited by exposure to alkaline pH in the absence of adenosine 5'-triphosphate (ATP). Relative V1 specific activity, taken as the ratio of V1 ATPase activity to percent alpha-heavy chain, doubles in the first 2.0 months after birth and then remains approximately constant at this higher level until at least 4 months after birth. The specific activity of V1 can be further increased by the addition of adenosine-3',5'-cyclic monophosphate (cAMP). This effect of cAMP is age dependent, increasing threefold between 1 and 2 months following birth and then declining as V1 is replaced by V3.
Circ Res 1987 Dec
PMID:cAMP regulation of myosin ATPase activity in the maturing rat heart. 282 92

The distribution of Ca2+-dependent adenosine triphosphatase (EC 3.6.1.3.) and nonspecific (Na-K-Mg) adenosine triphosphatase activity in the tegument and subtegumental tissues of Schistosoma mansoni from both mixed and single sex infections was investigated cytochemically. Differences in the distribution of tegumental Ca-adenosine triphosphatase activity in 60- to 70-day-old female worms were found which could be related to the degree of sexual development in the two types of females, with little or no tegumental activity being found in 70-day-old females from single sex infections. In contrast, 28-day-old females from single sex infections showed low levels of tegumental Ca-adenosine triphosphatase activity, suggesting that the lack of tegumental activity in 70-day-old single sex females may be due to a loss or suppression of activity as a consequence of the failure of females in single sex infections to pair and develop to full sexual maturity. No differences in the distribution of nonspecific (Na-K-Mg) adenosine triphosphatase activity between females from mixed and single sex infections were found. The sexual status or age of male worms appeared to have little or no effect on the distribution of tegumental adenosine triphosphatases.
Exp Parasitol 1987 Dec
PMID:Schistosoma mansoni: fine structural localization of tegumental adenosine triphosphatases. 282 32


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