23Na NMR measurement of the maximal rate of active sodium efflux from human red blood cells

1989 ◽  
Vol 9 (2) ◽  
pp. 261-272 ◽  
Author(s):  
T. L. Knubovets ◽  
A. V. Revazov ◽  
L. A. Sibeldina ◽  
U. Eichhoff
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Maximal Rate ◽  
Active Sodium ◽  
Sodium Efflux ◽  
Human Red Blood Cells ◽  
23Na Nmr

scholarly journals The Kinetics of Ouabain Inhibition and the Partition of Rubidium Influx in Human Red Blood Cells

1971 ◽  
Vol 57 (5) ◽  
pp. 576-592 ◽  
Author(s):  
L. A. Beauge ◽  
Norma Adragna
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Energy Supply ◽  
Time Lag ◽  
Active Sodium ◽  
Human Red Blood Cells ◽  
Rubidium Influx ◽  
Extrusion Mechanism ◽  
Sodium Extrusion ◽  
Ouabain Inhibition

In the development of ouabain inhibition of rubidium influx in human red blood cells a time lag can be detected which is a function of at least three variables: the concentrations of external sodium, rubidium, and ouabain. The inhibition is antagonized by rubidium and favored by sodium. Similar considerations could be applied to the binding of ouabain to membrane sites. The total influx of rubidium as a function of external rubidium concentration can be separated into two components: (a) a linear uptake not affected by external sodium or ouabain and not requiring an energy supply, and (b) a saturable component. The latter component, on the basis of the different effects of the aforementioned factors, can be divided into three fractions. The first is ouabain-sensitive, inhibited by external sodium at low rubidium, and requires an energy supply; this represents about 70–80% of the total uptake and is related to the active sodium extrusion mechanism. The second is ouabain-insensitive, activated by external sodium over the entire range of rubidium concentrations studied, and dependent on internal ATP; this represents about 15% of the total influx; it could be coupled to an active sodium extrusion or belong to a rubidium-potassium exchange. The third, which can be called residual influx, is ouabain-insensitive, unaffected by external sodium, and independent of internal ATP; this represents about 10–20% of the total influx.

scholarly journals A kinetic analysis of Na-Li countertransport in human red blood cells.

1986 ◽  
Vol 87 (3) ◽  
pp. 353-368 ◽  
Author(s):  
P A Hannaert ◽  
R P Garay
Keyword(s):  
Red Blood Cells ◽  
Kinetic Analysis ◽  
Blood Cells ◽  
Kinetic Properties ◽  
Maximal Rate ◽  
Apparent Dissociation Constant ◽  
Human Red Blood Cells ◽  
Ping Pong ◽  
Na Efflux ◽  
Cation Sites

We examined the kinetic properties of the interactions between inner and outer cation sites of the Na-Li countertransport system in human red blood cells. Li-stimulated Na efflux [V(Na)] was measured as a function of external Li [(Li)o] and internal Na [(Na)i] contents. At each (Li)o, a Hanes plot of (Na)i/V(Na) vs. (Na)i allowed us to calculate the apparent dissociation constant for internal Na (KiNa) and the maximal rate of Na efflux [Vmax(Na)]. In erythrocytes from 10 different subjects, the Vmax(Na)/KiNa ratios were independent of the external Li concentrations. In other experiments, Na-stimulated Li efflux [V(Li)] was measured as a function of external Na and internal Li contents. In three subjects studied, the Vmax(Li)/KiLi ratios were independent of the external Na concentrations. The data strongly suggest that the countertransport mechanism is consecutive ("ping-pong").

scholarly journals Transbilayer distribution and mobility of phosphatidylinositol in human red blood cells.

1990 ◽  
Vol 265 (27) ◽  
pp. 16035-16038 ◽  
Author(s):  
P Bütikofer ◽  
Z W Lin ◽  
D T Chiu ◽  
B Lubin ◽  
F A Kuypers
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Human Red Blood Cells
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