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An upper limit to the number of sodium channels in frog skin epithelium
Author(s) -
Cuthbert A. W.
Publication year - 1973
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1973.sp010106
Subject(s) - amiloride , frog skin , sodium , sodium channel , chemistry , epithelial sodium channel , epithelium , biophysics , biology , genetics , organic chemistry
1. Binding of [ 14 C]amiloride to the mucosal surface of frog skin epithelium has been measured in the presence and absence of an excess of unlabelled amiloride. Simultaneous records were obtained of the sodium transport through the skin as indicated by the short circuit current. 2. The number of binding sites with affinities for amiloride of 5 × 10 7 l./mole was around 400/μm 2 . 3. The relation between the binding sites and sodium channels is discussed. 4. Making certain assumptions it is concluded that when frog skin epithelium is bathed in Ringer solution each sodium channel can handle 8000 sodium ions/sec.