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)

The effect of calcitonin (CT) on Ca-ATPase activity in the plasma membrane fraction of rat liver was investigated. CT (80 MRC mU/100 g BW) administered subcutaneously to rats, caused a significant decrease in serum calcium, while increasing liver calcium. The administration of CT produced a rapid decrease of Ca-ATPase activity in the plasma membrane fraction of liver, whereas CT did not cause a significant alteration of p-nitrophenyl phosphatase activity. The maximal response of CT was obtained with 80 MRC mU/100 g BW. Meanwhile, the administration of imidazole (30 mg/100 g BW) which has a hypocalcemic effect, like CT, produced a significant increase in liver calcium and a corresponding fall in Ca-ATPase activity of the plasma membrane fraction. The reduction of Ca-ATPase activity produced by imidazole was significantly potentiated by the simultaneous administration of CT, and the rise in liver calcium was enhanced slightly. The present results suggest that the action of CT on liver calcium involves the decrease of Ca-ATPase activity in the plasma membrane of rat liver.
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PMID:Effect of calcitonin on Ca-ATPase activity of plasma membrane in liver of rats. 16 Aug 70

Except in thin muscles, the analysis of muscle capillary depends on direct ultrastructural visualization or histochemical identification of the capillaries using stains for basement membrane or reactions for endothelial cell enzymes. The accuracy of existing histochemical methods for detecting capillaries has not been systematically tested, however. The purpose of the present study was to compare muscle capillarity determined by two methods currently in use, Griffonia simplicifolia I lectin (GSI) and ATPase, with two alternative capillary markers, Lycopersicon esculentum lectin (LEA) and MRC OX.43 antigen. Capillarity, expressed as capillaries around fibers (CAF), was determined in the soleus, extensor digitorum longus, and sternomastoid muscles from 4-month-old female rats. The GSI, LEA, and MRC OX.43 capillary markers gave identical results for each muscle, confirming their validity as cytochemical probes. In contrast, the capillary ATPase method gave significantly lower CAF determinations, with a differential effect of preincubations at pH 4.4 vs 4.0. These data suggest that capillary ATPase acid stability varies within the capillary bed. The use of one or more of the alternative capillary markers tested is suggested for studies of muscle capillarity to confirm that binding sites or enzyme activity used for a given probe is expressed under both control and experimental conditions.
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PMID:Alternative histochemical markers for skeletal muscle capillaries: a statistical comparison among three muscles. 138 5

The mutagenicity of N-nitrosobis(2-oxopropyl)amine was measured in the V79 assay using homogenates of acinar cells and duct tissue from the pancreases of Syrian hamsters and MRC-Wistar rats as the activating systems. Mutations at the sodium/potassium ATPase and hypoxanthine:guanine phosphoribosyltransferase loci were measured by resistance to ouabain and 6-thioguanine (TG). The order of effectiveness in generating mutagens from BOP was hamster duct, hamster acinar, rat duct, rat acinar. These data show extensive differences in BOP activation by hamster acinar and duct tissue.
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PMID:The mutation of V79 cells by N-nitrosobis(2-oxopropyl)amine activated by pancreas acinar and duct tissue from Syrian hamsters and MRC-Wistar rats. 215 24

We have previously assigned human ecto-5'-nucleotidase (NT) to chromosome 6 on the basis of conversion of exogenously supplied [14C]AMP to adenosine by whole cells of human and Chinese hamster hybrids carrying chromosome 6. In this paper we demonstrate that the activity on human MRC-5 fibroblasts is typical of previously described and purified ecto-5'-nucleotidases. In contrast to MRC-5 cells, Chinese hamster V79A2 cells weakly express an AMPase activity that is not NT. The cytosolic form of NT in human and hybrid fibroblasts is similar to the ectoenzyme in substrate specificity. Hybrids that lack chromosome 6 express neither the ecto- nor the cytosolic enzyme, suggesting that both forms may be coded by the same gene on chromosome 6. Ecto-ATPase, ecto-ADPase, and ecto-ADP kinase activities are each expressed at similar levels in MRC-5 and V79A2. The ATPase, ADPase and NT activities of MRC-5 cells act sequentially to generate adenosine. A similar cascade acts on V79A2 cells but the lack of NT causes the accumulation of AMP.
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PMID:Nucleotide ectoenzyme activities of human and Chinese hamster fibroblasts in tissue culture. 256 Jun 29

The effect of calcitonin (CT) on calcium content and enzyme activity in the hepatic mitochondria of intact rats was investigated. A single subcutaneous administration of CT (80 MRC mU/100 g BW) produced a significant increase in the content of calcium, the activity of pyruvate carboxylase, succinate dehydrogenase and ATPase 15 min after the hormone treatment. The significant increases in calcium content and pyruvate carboxylase activity were also observed 30 min after CT administration, while succinate dehydrogenase and ATPase activity began to decrease. A physiological dose of CT (20 MRC mU/100 g BW) caused a marked increase in calcium content and pyruvate carboxylase activity but not succinate dehydrogenase of ATPase-activity. The removal of calcium by 10 mM EGTA washing of the mitochondria produced a remarkable reduction in pyruvate carboxylase activity increased by CT administration. The addition of calcium ion of 2.5 x 10(-2) - 2.5 x 10(1) nmoles Ca2+ per mg mitochondrial protein produced a marked increase in pyruvate carboxylase activity. The present results suggest that calcium taken up by the hepatic mitochondria after CT administration activates pyruvate carboxylase.
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PMID:Calcitonin increases pyruvate carboxylase activity in hepatic mitochondria of rats. 621 4

The change of subcellular phosphorus content in the liver was investigated after a single sc administration of synthetic [Asu1,7] eel calcitonin (CT) to fed rats. Administration of CT (80 MRC mU/100 g body weight) produced a significant increase in phosphorus content in the mitochondrial fraction, while this increase was not observed in fractions containing plasma membrane, nuclei, microsomes and cytosol. A significant increase in the mitochondrial phosphorus content was observed even at the lowest dose of CT (40 MRC mU/100 g body weight). A single ip administration of 2,4-dinitrophenol (0.1 mg/100 g body weight), an inhibitor of oxidative phosphorylation, did not prevent significant increases in phosphorus contents of the homogenate and the mitochondria caused by administration of CT (80 MRC mU/100 g body weight), although the drug markedly inhibited ATPase activity in the mitochondria. Administration of CT did not produce a significant alteration in the mictochondrial ATPase activity. These results suggest that phosphorus taken up by the liver cells after CT administration is largely located in the mitochondria, and that this increase is not related to oxidative phosphorylation. Presumably the hepatic mitochondria play a role in the storage of intracellular phosphorus increased by CT.
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PMID:Synthetic [Asu1,7] eel calcitonin increases phosphorus content in the hepatic mitochondria of rats. 622 93

The effects of calcitonin (CT), epinephrine and glucagon on the plasma membrane Ca-ATPase activity and the calcium content in the liver were investigated 30 min after a single subcutaneous administration of hormones to rats. Ca-ATPase activity in the plasma membrane fraction was significantly decreased by CT (80 MRC mU/100 g BW), while it was not significantly lowered by insulin (100 mU/100 g BW), epinephrine (100 micrograms/100 g BW), glucagon (50 micrograms/100 g BW), or parathyroid hormone (25 U/100 g BW). The calcium content in the liver was markedly increased by CT, while it was not significantly elevated by epinephrine or glucagon. Meanwhile, the decrease of Ca-ATPase activity in the plasma membrane fraction produced by CT was significantly prevented by simultaneous administration of epinephrine or glucagon, and also the increase in liver calcium was noticeably interfered with. The present results suggests that the action of CT on liver calcium may differ from that of epinephrine or glucagon which causes an increase in cyclic AMP in the liver cells.
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PMID:Comparison of calcitonin, epinephrine and glucagon effects on plasma membrane Ca-ATPase activity and calcium content in liver of rats. 644 62

Mesenteric lymphadenectomy in rats is followed by union of peripheral and central lymphatics, allowing the collection of intestine-derived peripheral lymph cells via the thoracic duct for several days. These cells include a proportion of nonlymphoid cells (NLC) that show irregular and heterogeneous surface morphology including long pseudopodia and veils. They stain variably for nonspecific esterase and acid phosphatase and are ATPase-positive. Their nuclei are irregular and some contain cytoplasmic inclusions, some of which show peroxidase activity and/or contain DNA. NLC have a range of densitites generally lower than that of lymphocytes. Freshly collected NLC express the leukocyte-common antigen (defined by monoclonal antibody MRC Ox 1) and Ia antigens (I-A and I-E subregion products defined by monoclonal antibodies) but they show a relative lack of other surface markers normally found on rat B or T lymphocytes (W3/13, W3/25, MRC Ox 12 (sIg), MRC Ox 19) or rat macrophages (FcR, C'R, mannose R, W3/25). In general NLC are only weakly adherent to glass or plastic. Although a subpopulation of NLC appear to have had a phagocytic past, freshly collected NLC fail to phagocytose a variety of test particles in vitro. NLC also appear incapable of pinocytosis in vitro. This heterogeneity may represent distinct subpopulations of NLC or different stages in the development of a single cell lineage. Direct cannulation of mesenteric lacteals shows that the majority of NLC are derived from the small intestine and their precursors appear to be present both in lamina propria and Peyer's patches. Kinetic studies, following irradiation or intravenous tritiated thymidine, show that the majority of NLC turn over rapidly in the intestine with a modal time of 3-5 d. Studies with bone marrow chimeras show that they are derived from a rapidly dividing precursor present in normal bone marrow. NLC occur at very low frequencies in normal thoracic duct lymph at all times following cannulation. The evidence presented suggests that NLC closely resemble mouse lymphoid dendritic cells. This conclusion is supported by evidence already obtained showing that NLC are potent stimulators of the semi-allogeneic rat primary mixed leukocyte reaction. In addition to the ceils resembling dendritic cells rare monocytoid cells are found in thoracic duct lymph of lymphadenectomized specific pathogen-free rats. The proportion of these cells increases greatly when the animals are conventionally housed. It seems probable that the physiological function of NLC is to act as accessory cells in the lymph nodes to which they normally drain. Methods for enriching NLC and thus facilitating analysis of their functions are discussed.
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PMID:Characterization of nonlymphoid cells derived from rat peripheral lymph. 685 8

The normal human fibroblast line, TIG-3 which senesces at around 80 population doubling levels (PDLs), expressed interferon (IFN)-inducible genes such as 6-16, 2', 5'-oligoadenylate synthetase (2,5-A) and HLA B7 near the end of the proliferative lifespan. Other normal fibroblast line such as MRC-5 also expressed IFN-inducible genes when senesced. Clones transformed with SV40 T-antigen, which extended their proliferative lifespan by about 20-30 PDLs, also expressed IFN-inducible genes during their extended life. Anti-IFN-beta antibodies added in culture medium repressed the expression of IFN-inducible gene in both normal senescent and life-extended SV40-transformed cells. IFN-beta repressed DNA synthesis in normal TIG-3 and induced IFN-inducible genes in both normal and SV40-transformed TIG-3. Conditioned medium recovered from life-extended SV40-transformed cells contained IFN-beta, but not IFN-alpha, IFN-gamma or TNF-alpha and possessed an activity that inhibited DNA synthesis of young TIG-3. Addition of anti-IFN-beta antibodies into the medium enhanced the serum-induced DNA synthesis of near senescent (91% lifespan completed) TIG-3, while it neither induced DNA synthesis in fully senescent TIG-3 nor extended the proliferative lifespan of TIG-3. These results suggest that normal and SV40-transformed human fibroblasts increase expression of IFN-beta with increasing proliferative age especially near the end of their lifespan resulting in induction of IFN-inducible genes and possibly in growth repression.
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PMID:Increase in expression levels of interferon-inducible genes in senescent human diploid fibroblasts and in SV40-transformed human fibroblasts with extended lifespan. 756 72

Infection of permissive human embryo fibroblasts (MRC-5) with human cytomegalovirus (HCMV) increased the number of copies of the Na+,K(+)-ATPase (the Na+ pump) in the plasma membrane, measured as ouabain-binding sites. The increase was preceded by cell enlargement by about 24 hr, becoming significant between 48 and 72 hr after infection. Reduction in Na+ or Cl- concentration in the culture media immediately after infection partially prevented the increase in the number of ouabain-binding sites. The effect was reversible upon restoring Cl- or Na+ to the incubation medium, but withdrawal of either ion at 24 or 48 hr PE failed to prevent the increase in the number of binding sites. These results suggest that the processes that resulted in the increase of copies of the Na+,K(+)-ATPase required both Na+ and Cl- during the first 24 hr PE. Amiloride and ethylisopropylamiloride, two inhibitors of Na+ transport mechanisms of the plasma membrane have been previously shown to reduce the amount of virus yields and to prevent the onset of cytomegaly (Fons et al., 1991, Proc. Soc. Exp. Biol. Med. 196, 89-96). We show here that these agents partially block the increase in ouabain-binding sites caused by HCMV infection.
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PMID:Human cytomegalovirus infection increases the number of ouabain-binding sites in human fibroblasts. 811 38


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