Sodium-coupled sugar transport: effects on intracellular sodium activities and sodium-pump activity

Science ◽  
1984 ◽  
Vol 224 (4654) ◽  
pp. 1237-1239 ◽  
Author(s):  
R. Hudson ◽  
S. Schultz
Keyword(s):  
Sodium Pump ◽  
Sugar Transport ◽  
Intracellular Sodium ◽  
Pump Activity ◽  
Transport Effects

Chlormadinone acetate, a progesterone derivative that binds to the digitalis receptor, inhibits the sodium pump in the isolated rat diaphragm

1985 ◽  
Vol 63 (1) ◽  
pp. 44-47 ◽  
Author(s):  
Ivan Bihler ◽  
Frank S. LaBella ◽  
P. C. Sawh
Keyword(s):  
Sodium Pump ◽  
Sugar Transport ◽  
Diaphragm Muscle ◽  
Rat Diaphragm ◽  
Bathing Medium ◽  
Chlormadinone Acetate ◽  
Muscle Tissues ◽  
Pump Activity ◽  
Intact Muscle ◽  
Resting Muscle

Rb+ uptake, intracellular Na+ and K+ levels, and the tissue–medium distribution of the nonmetabolized glucose analog, 3-O-methyl-D-glucose (3-MG) were measured in rat diaphragms incubated with chiormadinone acetate, 6-chloro-4,6-pregnadien-17-ol-3,20-dione 17-acetate (CMA), in the presence and absence of ouabain. CMA in concentrations of 5 × 10−7 M or higher significantly depressed 86Rb uptake, and promoted an increase in internal Na+ and a decrease in internal K+, indicating inhibition of the sodium pump. Sugar transport in resting muscle parallels the changes in internal Na+ levels and is an additional indicator of sodium pump activity. Equilibration of 3-MG between tissue and medium was accelerated by CMA, in parallel to the rise in internal Na+ level. Effects of CMA on Na+ levels and sugar transport, but not on Rb+ uptake, were additive to those of various concentrations of ouabain, suggesting interaction with sites not affected by ouabain. These results on diaphragm muscle confirm our previous studies on isolated cardiac muscle preparations showing that CMA, added to the aqueous bathing medium, inhibits the sodium pump in intact muscle tissues.

Ethanol predominantly alters sodium influx in human leucocytes

1990 ◽  
Vol 78 (2) ◽  
pp. 235-238 ◽  
Author(s):  
J. Main ◽  
T. Thomas
Keyword(s):  
Sodium Transport ◽  
Sodium Pump ◽  
Sodium Content ◽  
Intracellular Sodium ◽  
Exact Nature ◽  
Sodium Influx ◽  
Pump Activity

1. Although ethanol appears to alter cellular sodium transport, the exact nature of its effects has not been clearly defined. We have studied the effects of different concentrations of ethanol on human leucocyte sodium content, and on the rise in leucocyte sodium content which occurs during sodium pump blockade with ouabain. 2. Sodium content was significantly reduced after a 20 min incubation with ethanol at concentrations between 17 and 170 mmol/l. 3. The rise in sodium content during a 20 min incubation with ouabain was significantly less in the presence of 170 mmol/l ethanol as compared with 17 mmol/l ethanol. 4. These results suggest that the effect of ethanol on intracellular sodium content is independent of sodium pump activity, i.e. it is mediated through reduced sodium influx.

Interaction of alcohol and kola nut on brain sodium pump activity in Wistar rats

2009 ◽  
Vol 91 (2) ◽  
pp. 357-362
Author(s):  
G.O. Obochi ◽  
A.E. Abara ◽  
S.P. Malu ◽  
M.U. Eteng ◽  
I.B. Umoh
Keyword(s):  
Wistar Rats ◽  
Sodium Pump ◽  
Pump Activity

scholarly journals Inhibition of Na,K-ATPase by oleandrin and oleandrigenin, and their detection by digoxin immunoassays

1996 ◽  
Vol 42 (10) ◽  
pp. 1654-1658 ◽  
Author(s):  
S A Jortani ◽  
R A Helm ◽  
R Valdes
Keyword(s):  
Sodium Pump ◽  
Serum Proteins ◽  
Cross Reactivity ◽  
Pump Activity ◽  
Ic50 Values ◽  
On Line ◽  
Atpase Inhibition ◽  
Free Serum ◽  
Derivatives Of ◽  
Rule Out

Abstract Ingestion of oleander plant, containing the cardiac glycoside oleandrin, has been reported to induce fatal poisonings. Derivatives of oleandrin are structurally similar to digoxin. We investigated the cross-reactivities of oleandrin and its aglycone metabolite, oleandrigenin, in several commercially available digoxin immunoassays; assessed their ability to inhibit Na,K-ATPase catalytic activity; and measured their binding to proteins in serum. As assayed with ACS:180, Stratus, RIA, On-Line, and TDx digoxin assays, oleandrin at 100 micromol/L in digoxin-free serum gave apparent digoxin values of 0, 0.83, 2.24, 2.37, and 5.34 nmol/L, respectively, whereas oleandrigenin at that concentration gave results of 0, 0.52, 0.77, 4.94, and 1.40 nmol/L. Study of Na,K-ATPase inhibition showed IC50 values (micromol/L) of 0.22 for ouabain, 0.62 for oleandrin, 1.23 for oleandrigenin, and 2.69 for digoxin. At 25 degrees C, 96% of oleandrin and 48% of oleandrigenin were bound to serum proteins. Because detection of oleandrin and oleandrigenin by digoxin immunoassays is variable between assays as well as between congeners, assessment of cross-reactivity is warranted for each assay. The inhibition of Na,K-ATPase by oleandrin and oleandrigenin confirms that they likely exert their toxic effects through inhibition of sodium pump activity. In cases of digitalis-like poisoning with suspicion of oleander ingestion, a combination of digoxin immunoassays may be useful to effectively rule out the presence of oleander.

Regulation of cellular growth by sodium pump activity

1976 ◽  
Vol 87 (3) ◽  
pp. 377-387 ◽  
Author(s):  
Brenda Buckhold Shank ◽  
Nancy Egan Smith
Keyword(s):  
Sodium Pump ◽  
Cellular Growth ◽  
Pump Activity

scholarly journals Actions of vanadate on vascular tension and sodium pump activity in cat isolated cerebral and femoral arteries

1988 ◽  
Vol 93 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Carlos F. Sánchez-Ferrer ◽  
Jesús Marín ◽  
Magdalena Lluch ◽  
Angel Valverde ◽  
Mercedes Salaices
Keyword(s):  
Sodium Pump ◽  
Femoral Arteries ◽  
Pump Activity

Effects of Sodium Pump Activity on Spontaneous Firing in Neurons of the Rat Suprachiasmatic Nucleus

2006 ◽  
Vol 96 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Yi-Chi Wang ◽  
Rong-Chi Huang
Keyword(s):  
Suprachiasmatic Nucleus ◽  
Time Course ◽  
Sodium Pump ◽  
Membrane Depolarization ◽  
Inhibitory Response ◽  
Voltage Response ◽  
Spontaneous Firing ◽  
Whole Cell ◽  
Pump Activity ◽  
Cell Recording

Cell-attached and whole cell recording techniques were used to study the effects of electrogenic sodium pump on the excitability of rat suprachiasmatic nucleus (SCN) neurons. Blocking the sodium pump with the cardiac steroid strophanthidin or zero K+ increased the spontaneous firing of SCN neurons to different degrees with different recording modes, whereas turning the sodium pump into a nonselective cation channel with the marine toxin palytoxin invariably increased the spontaneous firing to the point of total blockade. Current-clamp recordings indicated that strophanthidin increased the rate of membrane depolarization and reduced the peak afterhyperpolarization potential (AHP), whereas zero K+ also increased the rate of depolarization, but enhanced the peak AHP. The dual effect of zero K+ was reflected by the biphasic time course of voltage responses to zero K+: an inhibitory phase with enhanced peak AHP and slower firing, followed by a delayed excitatory phase with faster rate of membrane depolarization and faster firing. In the presence of strophanthidin to block the sodium pump, zero K+ consistently decreased firing by enhancing the peak AHP. Repetitive applications of K+-free solution gradually turned the biphasic inhibitory-followed-by-excitatory voltage response into a monophasic inhibitory response in cells recorded with the whole cell (but not the cell-attached) mode, suggesting rundown of sodium pump activity. Taken together, the results suggest that spontaneous firing of SCN neurons is regulated by sodium pump activity as well as the AHP, and that sodium pump activity is modulated by intracellular soluble substances subject to rundown under the whole cell conditions.

scholarly journals Leucocyte sodium pump activity after meals or insulin

BMJ ◽  
1988 ◽  
Vol 296 (6617) ◽  
pp. 292-292 ◽  
Author(s):  
J. Main ◽  
T H Thomas ◽  
R Wilkinson
Keyword(s):  
Sodium Pump ◽  
Pump Activity
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