Potassium channels in rat prostate epithelial cells.
Voltage-dependent K(+) channels were identified and characterized in primary culture of rat prostate epithelial cells. A voltage-dependent, inactivating K(+) channel was the most commonly observed ion channel in both lateral and dorsal cells. The K(+) current exhibited a voltage threshold at -40 mV. Averaged half-inactivation potential (V(1/2)) and the slope factor (k) values were -26 mV and 6, respectively. It showed a monoexponential decay with an inactivation time constant of about 600 ms at +60 mV. The deactivation time constant at -60 mV was 30 ms and the reversal potential was estimated at -80 mV, suggesting that current was carried by potassium ions. The scorpion venom peptides charybdotoxin (5 nM) and margatoxin (1 nM), inhibited K(+) current at all membrane potentials with a rapid and a slow reversibility respectively. Both tetraethylammonium (10 mM) and 4-aminopyridine (50 microM) reduced K(+) current by approximately 40%. We conclude that plasma membranes of lateral and dorsal rat prostate epithelial cells contain Kv K(+) channels that have biophysical and pharmacological properties consistent with those of the Kv1.3 family.
Ouadid-Ahidouch
H
H
Laboratoire de Physiologie Cellulaire, Université de Lille I, INSERM EPI 9938, 59655, Villeneuve d'Ascq, France. halima.ouadid@univ-lille1.fr
Van Coppenolle
F
F
Le Bourhis
X
X
Belhaj
A
A
Prevarskaya
N
N
D000818:Animals; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism / Q000502:physiology; D016130:Immunophenotyping; D051664:Kv1.3 Potassium Channel; D008297:Male; D008564:Membrane Potentials; D015221:Potassium Channels / Q000096:biosynthesis* / Q000502:physiology; D024642:Potassium Channels, Voltage-Gated; D011467:Prostate / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
C496975:Kcna3 protein, rat; D051664:Kv1.3 Potassium Channel; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated