A chloride channel reconstituted from fetal rat brain growth cones.
Chloride channels were reconstituted into planar lipid bilayers isolated from a preparation of growth cone particles (GCPs) isolated from fetal rat brain. One type of channel was predominantly seen and some of its biophysical and pharmacological properties were studied. The single channel i-V relationship was curvilinear with a chord conductance of 75 pS at +30 mV in symmetric 200 mM NaCl solutions buffered with phosphate. The channel was inactivated by depolarization, and this inactivation was reversed rapidly upon returning to -25 mV. The Cl- channel was significantly permeant to Na+ ions (PNa/PCl = 0.26), and the relative halide permeabilities were determined to be: I(1.92) > Br(1.73) > Cl(1.0) > F(0.34). The channel was inhibited by the common stilbene compounds (DIDS, SITS, DNDS), as well as by Zn2+ ions and an indanyloxyacetic acid derivative. A developmental role for the GCP Cl- channel is suggested by the observation that adult rat brain synaptosomal membranes were nearly devoid of this type of Cl- channel.
Anesthesia Research Laboratories, Brigham and Women's Hospital, Boston, Massachusetts 02115.
J A
JA
DeBin
M R
MR
Wood
K H
KH
Pfenninger
G R
GR
Strichartz
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000166:cytology; D002462:Cell Membrane / Q000502:physiology*; D018118:Chloride Channels / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D008567:Membranes, Artificial; D051381:Rats; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology; D013267:Stilbenes / Q000494:pharmacology; D013574:Synaptosomes / Q000502:physiology
D018118:Chloride Channels; D008567:Membranes, Artificial; D013267:Stilbenes; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; C022306:4,4'-dinitro-2,2'-stilbenedisulfonic acid; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid