Single-channel properties of swelling-activated anion conductance
in rat inner medullary collecting duct cells.
Boese, Stefan H., Rolf K. H. Kinne, and Frank Wehner.
Max-Planck-Institut f[umlaut]ur molekulare Physiologie, Abteilung
Epithelphysiologie
APStracts 3:0161F, 1996.
Single-channel properties of the volume-activated outwardly rectifying
Cl- conductance of rat IMCD cells were studied in primary cultures by
means of the patch-clamp technique in the whole-cell and in the
outside-out configuration. Measurements were performed by noise
analysis and in single-channel recordings during voltage-induced
current inactivation and reactivation, and in long-lasting
experiments at constant membrane voltages. Unitary conductances could
be defined for the voltage range of -100 to -50 mV and between +50
and +120 mV and chord conductances of 34.1 and 76.6 pS, respectively,
can be calculated. The overall current-to-voltage relationship very
much resembles that of the macroscopic Cl- con ductance and the open
probability of the activated channel is close to unity (Po = 0.98 to
0.99). The channel exhibits many similarities to volume-activated
outwardly rectifying Cl- channels found in other systems although
certain species differences do exist.
Received 9 July 1996; accepted in final form 3 September 1996.
APS Manuscript Number F190-6.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996