• Joseph D. Robinson
Part of the People and Ideas Series book series (PEOPL)


By the 1930s, chemical analyses of vertebrate tissues—chiefly muscle—and of isolated cells—chiefly red blood cells—had demonstrated a peculiar and puzzling asymmetry. Tissues and cells generally contained high concentrations of potassium ions (K+) relative to sodium ions (Na+); by contrast, the environments of these tissues and cells, such as the blood plasma, contained the opposite concentration ratio: high Na+/low K+. Meanwhile, studies on the changeable contents of tissues and cells suggested that a membrane, although not visible by the microscopy of that time, surrounded each cell. Such a membrane could then have different permeabilities to solutes such as Na+ and K+. And investigations of excitable tissues, such as nerve and muscle, also focused on Na+ and K+ contents, with the electrical activity explained by some in terms of varying permeabilities to ions.


Permeability Hydrolysis Fermentation Chlorophyll Adenosine 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© American Physiological Society 1997

Authors and Affiliations

  • Joseph D. Robinson
    • 1
  1. 1.Department of PharmacologyState University of New York Health Science CenterSyracuseUSA

Personalised recommendations