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)

Using quantitative cytochemistry, activities of Na, K-ATPase, succinate dehydrogenase (SDH) and alpha-keto-glutarate dehydrogenase (alpha-KDH) was investigated in cells of renal tubules at different levels of sodium reabsorption in the kidney. The activity of these enzymes in mammals and birds renal tubule cells was found to be higher than in the cells of corresponding renal tubules of cold-blooded vertebrates. This corresponds to the increased total amount of reabsorbed sodium in the kidney of warm-blooded animals. The summer frogs, as compared to the winter ones, exhibit higher activities of SDH and Na,K-ATPase in the proximal tubule cells where changes in sodium reabsorption are also noted. In the kidney of marine teleosts, a negative correlation between U/PNa and the activity of SDH and Na,K-ATPase in the cells of proximal and distal tubule was observed. Aldosterone was found to stimulate sodium reabsorption and to activate Na,K-ATPase.SDH and alpha-KDH mainly in the distal convoluted tubule. Furosemide was observed to inhibit sodium reabsorption and to reduce SDH and Na,K-ATPase activities in cells of the proximal tubule and Henle's loop. In the kidney of adrenalectomized rats, both sodium reabsorption and activities of Na,K-ATPase, SDH, alpha-KDH decreased in all the segments of the nephron. The data obtained suggest that changes in sodium reabsorption may be coupled with those in the activities of the investigated enzymes.
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PMID:[A cytophotometric analysis of the activity of oxidative enzymes and Na, K-ATPASE in vertebrate nephrons at different levels of sodium transport in the kidney]. 13 80

Microsomal ATPase isolated from rat kidney papilla was compared to that from kidney medulla. Microsomal Na, K-ATPase from papilla was more sensitive to inhibition by ouabain, Cad N-ethyl-maleimide, Hg++, Thiomerin, ethacrynic acid and Furosemide than the enzyme from the medulla. Mg-ATPase of the papilla was less sensitive than the medullary enzyme to inhibition by Ca++, Cd++, N-ethyl-maleimide, Hg++, ethacrynic acid and Furosemide. Papillary Mg-ATPase was less sensitive than papillary Na, K-ATPase to all the inhibitors mentioned. Medullary Mg-ATPase was more sensitive than medullary Na, K-ATPase to inhibition by ethacrynic acid and Furosemide but less sensitive than medullary Na, K-ATPase to all the other inhibitors. Papillary Na, K-ATPase is the most sensitive to inhibition and papillary Mg-ATPase is the most resistant to inhibition by various diuretic drugs. The possible significance of these characteristics is discussed.
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PMID:Microsomal ATPase of kidney papilla: sensitivity to diuretics and other inhibitors. 14 22

Effects of three diuretics on the urinary Ca2+ excretion and on the microsomal Ca2+-activated ATPase were examined in the rat kidney. Furosemide and bumetanide increased Na+, K+, and Ca2+ excretion in the rats. Acetazolamide increased Na+ and K+ excretion but not Ca2+. Urinary inorganic phosphate excretion was not affected during the administration of acetazolamide. It is suggested that acetazolamide inhibits Na+ transport without affecting Ca2+ reabsorption in the rat nephron. Microsomal ATPase of the rat kidney cortex was stimulated by Ca2+ or Mg2+ alone and an additive effect of the two cations was not observed. Microsomal ATPase activated by Ca2+ or Mg2+ was not inhibited by furosemide, bumetanide, and acetazolamide. These data suggest that the inhibitory effect of furosemide and bumetanide on the Ca2+ reabsorption is not related to the inhibition of Ca2+-activated ATPase.
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PMID:Effects of diuretics on calcium excretion and Ca2+-activated ATPase in rat kidney. 14 65

Na+-K+-ATPase was inhibited by 1 times 10-4M ethacrynic acid and mercuderamide, and by 1 times 10-3M hydrochlorothiazide and furosemide. A modification of Gilman's (1970) protein displacement assay has been used to measure c-AMP levels in toad bladder epithelial cells. Vasopressin (50 mU/ml) caused c-AMP levels to rise from 4.27 to 9.27 pmol/mg protein. Ethacrynic acid had no effect on cellular c-AMP levels after 10 min exposure to the drug, but at 90 min caused a reduction of both basal and vasopressin stimulated levels. Furosemide caused an apparent rise in c-AMP levels, dilution ratio measurements indicated interference by this drug in the assay procedure, mecuderamide also caused substantial interference with the c-AMP assay. Hydrochlorothiazide had no effect on basal or hormone stimulated levels of c-AMP. It was concluded that the inhibition of sodium transport produced by ethacrynic acid in toad bladder is probably due to inhibition of adenylate cyclase, an effect not shared by other dieuretics.
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PMID:The effect of diuretics on Na+-K+-ATPase and c-AMP levels in toad bladder epithelial cells. 16 90

To investigate the role of Cl(-)-stimulated Mg(2+)-ATPase (Cl(-)-ATPase) in neurons, we examined the effects of ethacrynic acid (0.3 mM), which completely inhibits Cl(-)-ATPase on the intracellular Cl- concentrations of cultured rat hippocampal neurons, using Cl(-)-sensitive fluorescent probes. Ethacrynic acid and ATP consuming treatment increased the intracellular Cl- concentration, but elevation of the extracellular K+ concentration up to 10 mM, inhibition of Na+/K(+)-ATPase, or dissolution of H+ gradients had no effect. Furosemide (0.1 mM), an inhibitor of Na+/K+/Cl- co-transport, decreased the intracellular Cl- concentrations. These results indicate that an ethacrynic acid-sensitive and ATP-driven Cl- pump functions to reduce intraneural Cl- concentrations.
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PMID:An ATP-driven Cl- pump regulates Cl- concentrations in rat hippocampal neurons. 166 80

The addition of substrate in the form of lactate (L), but not glucose (G), increases the respiration of canine thick ascending limb (TAL) segments in a saturable (above 2 mM) fashion. More than 60% of this stimulation is ouabain-sensitive (1 mM ouabain) even if L and G transport are both sodium-insensitive processes in TAL. Thus L, but not G, specifically stimulates Na+ entry in TAL cells and its subsequent transport by the Na+,K(+)-ATPase. If chloride is substituted for by gluconate, no significant substrate-induced stimulation of ouabain-sensitive respiration is observed. SITS (4-acetamino-4'-isothiocyanostilbene-2,2'-disulfonic acid) also interferes with the L-induced stimulation of respiration. Thus L entry in TAL appears to be directly or indirectly coupled to the transepithelial flux of Cl-. Furosemide (F), but not amiloride, also inhibits this stimulation suggesting that the accelerated Na+ entry triggered by the application of L occurs through the F-sensitive carrier or that lactate transport is F-sensitive in TAL cells. In accord, F specifically impairs the metabolism of L (as compared to G). These data suggest that in intact TAL tubules both lactate uptake and oxidation are directly or indirectly influenced by the transcellular flux of NaCl. This organization may participate to maintain a stoichiometry between the transport of NaCl and the availability of L to support the energetic needs of TAL cells.
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PMID:Metabolism of lactate by a suspension of dog thick ascending limbs: relations with transport. 170 3

Infection of MA-104 cells with the OSU strain of rotavirus induced an increase in Na+ and a decrease in K+ intracellular concentrations, starting at 4 h post-infection. These changes were not related to an inhibition of the Na+/K+ pump since ouabain-sensitive 86Rb uptake was augmented in rotavirus-infected cells compared to control cells, whereas the [3H]ouabain binding and Na+/K+ ATPase activity in the cell homogenate were unaffected. Furosemide-sensitive 86Rb uptake (Na+/K+/2Cl- cotransport) was not modified by the infection. Passive 86Rb efflux and 22Na influx were augmented in infected cells suggesting an increase in the plasma membrane permeability. The increase in intracellular Na+ concentration might be responsible for the observed stimulation of the Na+/K+ pump. This effect was dependent upon the synthesis of viral proteins because it was abolished by addition of cycloheximide up to 4 h post-infection. Prevention of the increase in intracellular Na+ by the use of low Na(+)-containing media did not modify the pattern of protein synthesis. This suggests that changes in intracellular Na+ and K+ concentrations were not related to shutoff of cellular protein synthesis. Alterations of ion contents in the rotavirus-infected enterocytes might impair intestinal absorptive capacity before the appearance of histopathological lesions.
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PMID:Rotavirus infection alters Na+ and K+ homeostasis in MA-104 cells. 184 90

The expression of Ha-ras in quiescent NIH3T3 cells carrying a glucocorticoid-inducible human Ha-ras gene (Val-Gly mutation at codon 12) stimulates total 86Rb+ influx. This effect is predominantly due to an elevated 86Rb+ uptake through an ouabain-resistant, furosemide-sensitive system. The ouabain-sensitive Na+/K(+)-ATPase is less affected. The transport which is resistant to both inhibitors is not altered by Ha-ras. Overexpression of the Ha-ras proto-oncogene causes only a marginal increase in total 86Rb+ uptake. The stimulation of the furosemide-sensitive influx by Ha-ras is paralleled by an increase in mean cell volume which can be inhibited by furosemide. A rapid stimulation of the furosemide-sensitive Rb+ influx is also observed after addition of bombesin to growth-arrested cells. Furosemide inhibits the mitogenic response after expression of Ha-ras or addition of bombesin. Both the Ha-ras and the bombesin-induced stimulation of the furosemide-sensitive Rb+ transport can be blocked by protein kinase C depletion or the protein kinase C inhibitor staurosporine. In contrast to bombesin-induced phosphatidylinositol-4,5-bisphosphate hydrolysis which is down-modulated by Ha-ras, the stimulation of the furosemide-sensitive Rb+ influx by bombesin is elevated in Ha-ras-expressing cells. This is in accordance with the increased mitogenic activity of bombesin in Ha-ras-expressing cells.
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PMID:Stimulation of K+ transport systems by Ha-ras. 202 40

To study the short-term uptake of potassium across the basolateral membrane into individual tubule cells, rubidium was used and measured by electron microprobe analysis. Changes of rubidium uptake were interpreted to reflect altered sodium entry and basolateral Na-K-ATPase activity. The effects of hydrochlorothiazide, amiloride and furosemide were determined in saline-loaded animals. Hydrochlorothiazide inhibited rubidium uptake in proximal convoluted and distal convoluted tubule cells. The effect was largest in distal convoluted tubule cells. Amiloride reduced rubidium uptake in principal cells as well as in proximal convoluted, distal convoluted and connecting tubule cells. Furosemide depressed rubidium uptake in distal convoluted tubule cells, but increased uptake in principal cells. Rubidium uptake into intercalated cells was not affected by any of the diuretics used. Hydrochlorothiazide and amiloride altered rubidium uptake also in cells not associated with the main diuretic action. These effects of hydrochlorothiazide and amiloride may be due to interference with cell transport mechanisms of Na-H and anion exchange.
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PMID:Effect of diuretics on cell potassium transport: an electron microprobe study. 216 64

Stimulation-induced changes in Cl- content and O2 consumption of collagenase-isolated rat parotid acini were measured. In less than 10 s, carbachol caused a net Cl- efflux, corresponding to approximately 50% of the Cl- content, and increased the O2 uptake by 100%. The increase was inhibitable by ouabain and was dependent on the presence of extracellular Ca2+. Furosemide reduced the unstimulated 36Cl- uptake and prevented the reuptake of Cl- after carbachol-induced release. This suggests that a cotransport system is operating in both the unstimulated and stimulated states. Furthermore, furosemide inhibited the stimulated ouabain-sensitive O2 uptake. Raising intracellular Ca2+ by the calcium ionophore A23187 evoked the same pattern of Cl- loss and O2 uptake as carbachol. Our results are compatible with the following hypothesis. Carbachol raises intracellular Ca2+, causing an increased Cl- permeability of the luminal membrane, resulting in a net Cl- efflux. A subsequently enhanced influx of Cl- and Na+ via a furosemide-sensitive cotransport system increases intracellular Na+. This stimulates the Na+-K+-ATPase and thereby the O2 consumption.
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PMID:Effects of Ca2+ and furosemide on Cl- transport and O2 uptake in rat parotid acini. 242 56


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