The effects of anions on sodium transport



  • 1Substitution of chloride by isethionate reduces the short circuit current (SCC) and increases the potential of isolated frog skin. In sodium isethionate Ringer antidiuretic hormone and choline chloride increase the SCC, whereas theophylline is ineffective.
  • 2Frog skins treated on the outside with copper ions always show an increased potential when bathed in normal Ringer solution. The SCC may be moderately increased or decreased.
  • 3Theophylline increases skin thickness and cell volume in non-short-circuited skins.
  • 4The ways in which the theophylline-induced increase in chloride permeability affects sodium transport is discussed, together with the requirements for a permeant anion in both short- and open-circuited skins.