Insulin-activated amiloride-blockable nonselective cation and Na+ channels in the fetal distal lung epithelium.

Tohda H, Marunaka Y

MRC Group in Lung Development, Hospital for Sick Children Research Institute, University of Toronto Faculty of Medicine, Ontario, Canada.

Gen Pharmacol. 1995 Jul;26(4):755-63. doi: 10.1016/0306-3623(94)00247-k.

Abstract

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.

摘要