The effect of ouabain, meralluride and ethacrynic acid on respiration and glycolysis in kidney slices

Jones, Vernon D.; Landon, Erwin J.

doi:10.1016/0006-2952(67)90015-9

Cited by 30 publications

(11 citation statements)

References 34 publications

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“…The present work shows that the compound inhibited ATPase activity and lactate production in human red cells, and again it was different from ouabain in also decreasing the parts of the activities which were independent of the Na pump. Respiration and glycolysis in kidney slices and mitochondrial respiration are also inhibited by etha-130 H. LUBOWITZ AND R. WHITTAM crynic acid in a different way from ouabain (Jones & Landon, 1967;Landon, 1967). So far as the inhibition of unidirectional ion movements is concerned we have confirmed and extended the work of Hoffman & Kregenow (1966) and Hoffman (1966).…”

Section: Discussionsupporting

confidence: 74%

Ion movements in human red cells independent of the sodium pump

Lubowitz¹,

Whittam²

1969

The Journal of Physiology

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SUMMARY1. A study was made of the dependence on external Na of the movements of Na and K in human red cells. Special attention was given to ouabain-insensitive movements. The effect of internal Na on Na influx, and the influence of some sulphydryl inhibitors on ion movements and metabolism was also investigated.2. External Na stimulated ouabain-insensitive Na efflux and K influx. There was also a ouabain-insensitive component of Na influx that was raised on increasing the internal Na concentration. Exchange diffusion of Na appears to occur in the presence of ouabain and external K.3. Net transport of Na and K in the presence of ouabain was independent of external Na, as was also lactate production.4. Ethacrynic acid partially inhibited the Na pump; the Na-dependent components of Na efflux and K influx in the presence of ouabain were completely inhibited by ethacrynic acid. Both ouabain-sensitive and ouabain-insensitive adenosinetriphosphatase activities were inhibited by ethacrynic acid indicating a non-specific effect of this compound. Jodoacetamide decreased only the ouabain-insensitive ATPase activity.5. The results suggest that when the Na pump is blocked by ouabain, part of the residual ion movements can be attributed to exchange diffusion.

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Section: Discussionsupporting

confidence: 74%

Ion movements in human red cells independent of the sodium pump

Lubowitz¹,

Whittam²

1969

The Journal of Physiology

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“…The remarkable decrease of 3-phosphoglycerate (from 193 to 54 nmoles/g dry weight) indicates that the two last-mentioned enzymes are rate-limiting. This is in accord with observations on ouabain-treated cerebral cortex slices [30], kidney slices [31] or erythrocytes [32]. An argument against phosphofructokinase activation is the decrease of AMP, a powerful effector of this kinase [12].…”

Section: Ouabain Effectsupporting

confidence: 88%

Short‐Term Effects of Calcium, Potassium, and of Ouabain on Metabolite Levels in the Frog Heart in vivo

Arese

Bosìa

Rossini

1969

European Journal of Biochemistry

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The short-term effects of calcium (7.2 mM), potassium (10.7 mM), and of ouabain (O.lO/,,) have been studied in the frog heart in vivo. No dynamic alterations occurred a t 30 see, whereas positive inotropism was observed at 60 see in the high-Ca and ouabain treatment; in all cases heart arrest occurred a t 120 see. 18 metabolites (glucose, glucose-I-P, glucose-6-P, fructose-6-P, fructose-1,6-Pz , dihydroxyacetone-P , glyceraldehyde-3-P , a-P-glycerol, pyruvate, lactate, oxaloacetate, malate, a-ketoglutarate, P-creatine, creatine, ATP, ADP, AMP) and 17 added parameters (mass-action ratios of the phosphoglucomutase, phosphohexose isomerase, triosephosphate isomerase, phosphofructokinase, aldolase, adenylate kinase, creatine kinasc ; redox ratios ; ratios P-creatine/creatine, ATP/AI>P; sums P-creatine + creatine, ATP + ADP + AMP, lactate + pyruvate) were computerized by the stepwise discriminant analysis. Highly significant discrimination between control and treated hearts (thanks to the sensitivity of the statistical method employed) shows that ionic shifts and ouabain elicited modifications of the metabolite pattern which always preceded the effects on heart contractility.The most meaningful results were as follows: 1. High calcium effect: At 30 see, the phosphofructokinase-catalyzed step and the pyruvate, a-P-glycerol and oxaloacetate-depleting reactions are activated ; the P-creatine and ATP balance is negative ; ADP and AMP are increased. At 60 and 120 see the phosphorylase system, phosphofructokinase, and the whole glycolytic sequence are activated.2 . High-potassium effect : At 30 see the phosphofructokinase-step and the glycolytic flux are activated. Glucose entry into the cell is impaired. P-creatine, ATP, AMP, ATP/ADP, P-ereatinel creatine are increased. At 60 see, all glycolytic substrates are increased.3. Ouabain effect: At 30 sec glucose extraction from the perfusing fluid decreases, lactate, pyruvate, a-P-glycerol and malate accumulate; P-creatine and ATP are increased. At 60 see there is no evidence for activation of the phosphorylase system ; the glycolytic pattern points to activation of glucose extraction and of the glucose shunt, and to inhibition of the glyceraldehyde-3 -P dehydrogenase and 3-P-glycerate kinase steps. P-creatine, ATP, and AMP are decreased, creatine and ADP increased. The partial overlapping of the high-calcium and ouabain patterns suggests that the glycoside not only raises the intracellular free-calcium level but also depresses the glyceraldehyde-3-P dehydrogenase, 3-P-glacerate kinase and adenylate cyclase activity. The observed effects are only partially in accord with the inhibition of Na+-K+-dependent adenosinetriphosphatase.Unusual Abbreviations. Adenosine 3',5'cyclophosphate, ryclic AMP. Other abbreviations are according to CBN rilles [European J. Bioehem.

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“…The slow inhibitory action of EA on insulin secretion may be due to a slow penetration of this drug into the beta cell, where it probably binds to SH groups of enzymes of glycolysis and oxidative phosphorylation, as demonstrated in cell free preparations [17,18] and in intact cells [19][20][21]. Slow penetration into the beta-cell could be measured for other SH-groups blocking agents [5,[22][23][24].…”

Section: Discussionmentioning

confidence: 99%

Sulphydryl requirement for insulin release from the perfused pancreas

1978

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Summary. Using the isolated, perfused rat pancreas the importance of sulphydryl groups for the secretory process of insulin was investigated. It was found that ethacrynic acid (EA, 0.075-0.6 mmol/1) caused a dose-dependent, monophasic insulin release. Addition of EA to a glucose-stimulated (20 mmol/1) pancreas led to a sudden increase in hormone release, followed by a dose-dependent inhibition of release, which was not reversible after removal of EA. The same phenomenon was seen in the presence of 20mmol/1 leucine. Dithiothreitol (DTF, 0.1 and 1 mmol/1) had no effect on basal insulin secretion. Added to a glucose-stimulated pancreas DTF (1 mmol/1) caused a reversible inhibition of insulin release. The persistent inhibitory action of EA on glucose-induced insulin release could be reversed by simultaneous perfusion of EA and DTT. Sequential exposure of a glucose-stimulated pancreas to EA and DTT led to a rapid release of insulin, due to DTI'; however, the EA-induced inhibition of insulin secretion could not be prevented. Two kinds of thiol groups in the plasma membrane and in the beta cell might be responsible for the various kinetics of insulin release induced by EA and DTT. Ethacrynic acid (EA), another potent sulphydrylgroup blocking reagent, has been shown to prevent glyceryl-trinitrate-induced relaxation of smooth muscle, while dithiothreitol (DTT) has the opposite effect [7]. Since EA might also influence glucose tolerance, it is an interesting substance for further study of the role of SH-groups in the process of insulin secretion. Therefore, perfusions of isolated rat pancreas with each drug alone, with both drugs together and with the drugs in combination with glucose or leucine were performed. Materials and Methods MawrialsD-glucose and L-leucine were obtained from Merck AG, Darmstadt. Ethacrynic acid (sodium salt) was from Merck, Sharp and Dohme, Munich, and dithiothreitol (Cleland reagent) from Serva, Heidelberg. Bovine serum albumin (electrophoretic purity 100%) was purchased from Behringwerke, Marburg. Dextran (MW 60,000-80,000) from Knoll AG, Ludwigshafen, was dialyzed against twice distilled water to remove traces of contaminating glucose. The other reagents used were of analytical grade form Merck, Darmstadt. Animals and Perfusion ProcedureMale Sprague-Dawley rats, weighing between 160-350 g, fed ad libitum with Altromin ®, were used as pancreas donors. Details of the isolation and perfusion procedure are described elsewhere [8,9].

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The effect of ouabain, meralluride and ethacrynic acid on respiration and glycolysis in kidney slices

Cited by 30 publications

References 34 publications

Ion movements in human red cells independent of the sodium pump

Ion movements in human red cells independent of the sodium pump

Short‐Term Effects of Calcium, Potassium, and of Ouabain on Metabolite Levels in the Frog Heart in vivo

Sulphydryl requirement for insulin release from the perfused pancreas

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