Referenced in: none

Automatically associated channels: Kir2.3

Title: Two types of potassium current in rabbit cultured Schwann cells.

Authors: J R Howe, J M Ritchie

Journal, date & volume: Proc. R. Soc. Lond., B, Biol. Sci., 1988 Oct 22 , 235, 19-27

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/2467306

Abstract
Voltage-gated outward currents were studied in rabbit cultured Schwann cells with the 'whole-cell' configuration of the patch-clamp method. Four components of such currents were identified. The first, which was abolished by replacement of the external chloride ions by the large impermeant anion gluconate, was identified as a chloride current. The second and third were identified as potassium currents. One type of potassium current was reduced substantially by either 4-aminopyridine (4-AP) or tetraethylammonium ion (TEA). Its sensitivity to blocking by 4-AP was highly voltage-dependent: the equilibrium dissociation constant (K) was threefold greater when measured at +10 mV than when measured at -40 mV (where it was about 80 microM). The second type of potassium current was relatively insensitive to 4-AP, but was blocked by TEA. The TEA sensitivity of the two types of potassium currents was similar and displayed no obvious voltage-dependence (K approximately 200 microM). The fourth component of current was not reduced by 4-AP or TEA at concentrations less than 10 mM. Whether or not this last component is a potassium current is unclear.