Influence of Ethacrynic Acid on Muscle Surface Enzymes and of Ethacrynic Acid and Ouabain on Na, K, and H2O in Frog Muscle

1972 ◽  
Vol 50 (5) ◽  
pp. 432-444 ◽  
Author(s):  
J. R. Riordan ◽  
J. F. Manery ◽  
E. E. Dryden ◽  
T. S. Still
Keyword(s):  
Adenylate Kinase ◽  
Ethacrynic Acid ◽  
Narrow Range ◽  
Total Concentration ◽  
Frog Muscle ◽  
Muscle Membrane ◽  
Amp Deaminase ◽  
Passive Permeability ◽  
Minimum Concentration ◽  
Presence And Absence

Isolated frog muscles were exposed to concentrations of ethacrynic acid (2,3-dichloro-4-(2-methylene-butyryl)phenoxyaceticacid)ranging from 10−8 to 10−2 M. The diuretic (EA) at a concentration (10−3 M) which is sufficient to markedly inhibit net Na and K movements had no effect on three muscle surface enzymes (ATPase, adenylate kinase, 5′-AMP deaminase). The minimum concentration of EA required for inhibition of Na and K movement lies within the narrow range of 0.2 × 10−3 M to 10−3 M. The degree of inhibition increased with EA concentration up to 10−2 M. Concentrations of 0.2 × 10−3 M caused some contracture of the muscles as well. EA causes an increased K loss over that caused by ouabain alone both in the presence and absence of external Na. Na concentrations are not affected. Ouabain causes increased K loss over that caused by EA alone both in the presence and absence of external Na. Frog muscle has a component of K movement (about 35% of the total concentration) dependent upon external Na. This component is distinct from the ouabain-inhibited component and equal to the EA-inhibited component. The results are consistent with inhibition of the active transport of Na and K by EA as well as by ouabain and suggest that in the presence of Ca, EA also increases the passive permeability of the muscle membrane to K.

Characteristics of nucleotide-converting enzymes at muscle surfaces with special reference to ion sensitivity

1968 ◽  
Vol 46 (3) ◽  
pp. 537-547 ◽  
Author(s):  
J. F. Manery ◽  
J. R. Riordan ◽  
E. E. Dryden
Keyword(s):  
Adenylate Kinase ◽  
Inorganic Phosphate ◽  
Enzyme System ◽  
Choline Chloride ◽  
Frog Muscle ◽  
Magnesium Ions ◽  
Amp Deaminase ◽  
Ultraviolet Range ◽  
Incubation Periods ◽  
Sodium And Potassium

Spectral analyses in the ultraviolet range, paper chromatography, and determinations of the release of inorganic phosphate were used to extend the investigation of the surface enzymes (frog muscle) which catalyze the conversion of ATP→ADP→AMP→IMP. ATPase and 5′-AMP deaminase appear to adhere firmly to the muscle cell surface, even after three successive incubation periods of 4 h each, whereas the adenylate kinase is more loosely bound. The observed loss of the activity of the complete enzyme system with time was shown to be due to a suboptimal substrate concentration and not to the accumulation of products of the reaction. The AMP deaminase activity was inhibited if sodium and potassium chloride were replaced by choline chloride in the incubation media. Cation analyses of media and the determination in muscle of Na, K, water, and the sorbitol-14C space permitted a calculation of the actual intra- and extra-cellular cation concentrations. In choline-containing media the intracellular potassium was in part replaced by choline. The data indicated that the deaminase was influenced by the external, not the internal, cation concentrations. Magnesium ions stimulated the inorganic phosphate release catalyzed by ATPase and adenylate kinase but inhibited the AMP deaminase. Intact frog muscle also converted GTP, CTP, UTP, and ITP in the medium to the corresponding nucleoside monophosphate.

Distribution of enzymes of adenylate and guanylate nucleotide metabolism in rat nephron

1982 ◽  
Vol 243 (4) ◽  
pp. F349-F355
Author(s):  
B. R. Cole ◽  
A. E. Hays ◽  
J. G. Boylan ◽  
H. B. Burch ◽  
O. H. Lowry
Keyword(s):  
Adenylate Kinase ◽  
Metabolic Pathways ◽  
High Energy ◽  
Nucleotide Metabolism ◽  
Thick Ascending Limb ◽  
Amp Deaminase ◽  
Patterns Of Distribution ◽  
Degradative Enzyme ◽  
Convoluted Tubules ◽  
Nephron Heterogeneity

In a previous study of discrete segments of rat nephron, we reported the levels of high-energy adenylate and guanylate phosphates to be highest in the distal straight and convoluted tubules. Those findings stimulated the study of the distribution of seven enzymes involved in the following metabolic pathways of these nucleotides [Formula: see text]. The patterns of distribution of enzymes in each pathway differed greatly. The phosphodiesterases, 1 and 2, were high in glomeruli and distal tubular segments and low in proximal segments. Adenylate kinase, 3, in contrast, was high in glomeruli, proximal segments, thick ascending limb of Henle, and distal convoluted tubules. Guanylate kinase levels, 4, however, were similar in all segments. The pattern of nucleosidediphosphate kinase, 5, was high in proximal convoluted, thick ascending limb, and distal convoluted tubules. The pattern of the degradative enzyme, 5'-nucleotidase, 6, whose levels were highest in proximal segments, was opposite from that of AMP deaminase, 7, highest in the distal nephrons. These dissimilar patterns underscore the extent of nephron heterogeneity.

scholarly journals The activity of creatine kinase in frog skeletal muscle studied by saturation-transfer nuclear magnetic resonance

1981 ◽  
Vol 194 (1) ◽  
pp. 215-228 ◽  
Author(s):  
D G Gadian ◽  
G K Radda ◽  
T R Brown ◽  
E M Chance ◽  
M J Dawson ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Adenylate Kinase ◽  
Relative Increase ◽  
Frog Muscle ◽  
Saturation Transfer ◽  
Large Magnitude ◽  
Forward Reaction ◽  
Reaction Flux ◽  
Creatine Kinase Reaction ◽  
Resting Muscle

1. The activity of creatine kinase in intact anaerobic frog muscle at 4 degrees C at rest and during contraction was investigated by using saturation-transfer 31P n.m.r. 2. At rest, the measured forward (phosphocreatine to ATP) reaction flux was 1.7 × 10(-3) M . s-1 and the backward flux was 1.2 × 10(-3) M . s-1. The large magnitude of both fluxes shows that creatine kinase is active in resting muscle, so the observed constancy of [phosphocreatine] demonstrates that the enzyme and its substrates are at equilibrium. 3. The apparent discrepancy between the fluxes must arise largely from an underestimation of the backward flux resulting from interaction of ATP with other systems, e.g. via adenylate kinase. For purposes of further calculation we have therefore adopted 1.6 × 10(-3) M . s-1 as an estimate of both fluxes. 4. During contraction, when the creatine kinase reaction is no longer at equilibrium, the net rate of phosphocreatine breakdown, estimated directly from the change in area of the inorganic phosphate peak, was 0.75 × 10(-3) M . s-1. Saturation transfer indicates that the forward reaction flux remains at approx. 1.6 × 10(-3) M . s-1 and the backward flux decreases to about 0.85 × 10(-3) M . s-1. 5. The activity of creatine kinase during contraction is large enough to account for the well-established observation that, during contraction, the concentration of ATP falls by less than 2-3%. The reaction catalysed by creatine kinase is driven forward during contraction by the large relative increase in the concentration of free ADP, which is more than doubled. 6. The observation that the forward flux does not increase during contraction and that the backward flux decreases can most simply be explained on the basis of competition of reactants for a limited amount of enzyme.

scholarly journals The Suppression of the Late After-Potential in Rubidium-Containing Frog Muscle Fibers

1965 ◽  
Vol 48 (6) ◽  
pp. 1003-1010 ◽  
Author(s):  
D. C. Hellam ◽  
D. A. Goldstein ◽  
L. D. Peachey ◽  
W. H. Freygang
Keyword(s):  
Membrane Potential ◽  
Potassium Concentration ◽  
Muscle Fibers ◽  
Frog Muscle ◽  
Muscle Membrane ◽  
Potassium Permeability ◽  
Intracellular Potassium ◽  
Intracellular Potassium Concentration

The late after-potential that follows trains of impulses in frog muscle fibers is virtually absent when most of the intracellular potassium is replaced by rubidium and the muscle is immersed in rubidium-containing Ringer's fluid. Its amplitude is also reduced in freshly dissected, potassium-containing muscle fibers that are immersed directly in Rb-Ringer's fluid. These findings are discussed in terms of the model for muscle membrane of Adrian and Freygang (1962 a, b) and in relation to the report of Adrian (1964) that Rb-containing muscle fibers do not exhibit the variations in potassium permeability as a function of membrane potential that are found in fibers with normal intracellular potassium concentration immersed in Ringer's fluid.

Normal activities of AMP-deaminase and adenylate kinase in patients with McArdle disease

2016 ◽  
Vol 38 (12) ◽  
pp. 1052-1055 ◽  
Author(s):  
Pushpa Raj Joshi ◽  
Thekla Apitz ◽  
Stephan Zierz
Keyword(s):  
Adenylate Kinase ◽  
Amp Deaminase ◽  
Mcardle Disease

scholarly journals Complete quantification of the total concentration of rat skeletal-muscle Na+ + K+-dependent ATPase by measurements of [3H]ouabain binding

1986 ◽  
Vol 240 (3) ◽  
pp. 725-730 ◽  
Author(s):  
K Kjeldsen
Keyword(s):  
Binding Sites ◽  
Binding Assay ◽  
Total Concentration ◽  
Muscle Membrane ◽  
Ouabain Binding ◽  
Dependent Atpase ◽  
Activity Measurements ◽  
Standard Assay ◽  
Specific Uptake ◽  
Old Rats

In the standard [3H]ouabain-binding assay for quantification of the Na,K-ATPase (Na+ + K+-dependent ATPase) concentration in rat skeletal muscles, samples are incubated for 2 × 60 min in 1 microM-[3H]ouabain at 37 degrees C followed by a wash-out for 4 × 30 min at 0 degree C. To obtain accurate determinations, values determined by this standard assay should be corrected for non-specific uptake and retention of [3H]ouabain (11% overestimation), loss of specifically bound [3H]ouabain during wash-out (21% underestimation), evaporation from muscle samples during weighing (4% overestimation), impurity of [3H]ouabain (5% underestimation) and incomplete saturation of [3H]ouabain binding sites (6% underestimation). Thus corrected the standard [3H]ouabain-binding assay determines the total Na,K-ATPase concentration. Hence, in the soleus muscle of 12-week-old rats the total [3H]ouabain-binding-site concentration is 278 +/- 20 pmol/g wet wt. This is at variance with the evaluation of the Na,K-ATPase concentration from Na,K-ATPase activity measurements in muscle membrane fractions, where the recovery of Na,K-ATPase is only 2-18%. Quantification of the total Na,K-ATPase concentration is of particular importance since it is a prerequisite for the discussion of quantitative aspects of the Na,K-ATPase.

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