A Cl- channel with large single-unit conductance and characteristic voltage-dependent inactivation was studied on cultured human fibroblasts. The channel was activated only after excision and lasting depolarization of the membrane patch. In inside-out configuration and in symmetrical 135 mM NaCl, the conductance was 300 pS. The channel was usually open at the membrane potentials between -20 to +20 mV, while more negative or positive voltages closed the channel. The time course of this apparent inactivation process was dependent on increasing potential. Recovery from inactivation was made possible by returning the membrane potential to 0 mV. The channel was selective to Cl- over Na+ with a PCl PNa of 6. The order of permeability among anions was: I>BrCl>isethionate>F>glutamate. The channel was blocked by internal application of a derivative of the diphenylamine-2-carboxilate (Blocker 144) but not by 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid.
|Number of pages||8|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - Jul 29 1988|
ASJC Scopus subject areas
- Molecular Biology