|
|
|
|
|
|
|
||
ARTICLE |
Measurements have been made on the permeability of the human erythrocyte to Na and K in vitro, using radioactive tracers to observe the system in the steady state. The average inward K flux is 1.67 m.eq./liter cells hour, and the apparent activation energy is 12,300 ± 1300 calories/mol. The inward K flux is independent of the external K concentration in the range of concentrations studied (4 to 16 m.eq. K/liter plasma). Rb appears to compete with K for transport into the cell, whereas Na and Li do not. The average inward Na flux is 3.08 ± 0.57 m.eq. Na/liter cells hour, and the apparent activation energies are 20,200 ± 2700 calories/mol for inward transport, and 14,900 ± 3,400 calories/mol for outward transport. The inward Na flux is dependent on the external Na concentration, but not in a linear fashion. Li appears to compete with Na for inward transport, whereas K and Rb do not.
An approximate maximum estimate shows that the energy required for cation transport is only 8.8 calories/mol liter cells hour of the 110 calories/mol liter cells hour available from the consumption of glucose. A working hypothesis for the transport of Na and K is presented.
Submitted on March 13, 1952
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  G. C. HENEGAR, R. W. FRISKEY, and F. W. PRESTON In Vitro Incorporation of Rb86 by the Erythrocyte as an Index of Intracellular Potassium Arch Surg, June 1, 1959; 78(6): 862 - 867. [Abstract] [PDF]
|
|
|
|
 |
|
 R. E. Bernstein Potassium and Sodium Balance in Mammalian Red Cells Science, September 17, 1954; 120(3116): 459 - 460. [PDF]
|
|
|
|
