Insulin-activated amiloride-blockable nonselective cation and Na+ channels in the fetal distal lung epithelium.
1. The apical membrane of fetal distal lung epithelium had two types of amiloride-blockable Na(+)-permeant cation channels; (1) nonselective cation (NSC) channel with a single channel conductance of 27 pS and (2) Na+ channel with a single channel conductance of 12 pS around resting membrane potential. 2. The IC50 of amiloride to the Na+ channel was 1-2 microM, while the IC50 of amiloride to the NSC channel was less 1 microM. The open probability of the Na+ channel was about 10-fold larger than that of the NSC channel. 3. Insulin (100 nM) increased the open probability of both channels.
Tohda
H
H
MRC Group in Lung Development, Hospital for Sick Children Research Institute, University of Toronto Faculty of Medicine, Ontario, Canada.
Marunaka
Y
Y
D000584:Amiloride / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism*; D008168:Lung / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D018408:Patch-Clamp Techniques; D011650:Pulmonary Alveoli / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D015222:Sodium Channels / Q000187:drug effects / Q000378:metabolism*
D007328:Insulin; D007473:Ion Channels; D015222:Sodium Channels; D000584:Amiloride