Recording of a large conductance chloride channel in normal rat
lactotrophs.
Fahmi, M., L. Garcia, A. Taupignon, B. Dufy, P. Sartor.
Laboratoire de Neurophysiologie, CNRS URA 1200, Universit[umlaut]a
de Bordeaux 2, 146 rue L[umlaut]ao Saignat, 33076 Bordeaux Cedex,
France
APStracts 2:0143E, 1995.
Membrane current fluctuations resembling channel openings and closings
were observed in the whole-cell configuration of the patch-clamp
technique in normal rat lactotrophs in primary culture. Using high
gain headstage in whole cell configuration, we characterized the
nature and pharmacological properties of the ionic channel underlying
these fluctuations. This channel, found in small numbers, less than
ten per cell, was specific for chloride (Cl-) since its reversal
potential varied with Cl- gradients, according to Nernsts equation,
and its unitary amplitude was linearly related to membrane potential
from - 100 to 0 mV. Slope conductance was close to 100 pS. Analyzing
open times, we demonstrated its Ca2+- and potential-dependence. Four
sublevels were observed. We suggest that this channel, belonging to
the background Cl- channel group, take part in the regulation of
intracellular chloride concentration of normal rat lactotrophs.
Received 21 March 1995; accepted in final form 21 June 1995.
APS Manuscript Number E130-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 11 July 1995.