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, Avera ged half-inactivation potential (V-1/2) and the slope factor (k) values wer e -26 mV and 6, respectively. It showed a monoexponential decay with an ina ctivation time constant of about 600 ms at +60 mV, The deactivation time co nstant at -60 mV,vas 30 ms and the reversal potential was estimated at -80 mV, suggesting that current was carried by potassium ions. The scorpion ven om peptides charybdotoxin (5 nM) and margatoxin (1 nM), inhibited K+ curren t at all membrane potentials with a rapid and a slow reversibility respecti vely, Both tetraethylammonium (10 mM) and il-aminopyridine (50 mu M) reduce d K+ current by similar to 40%, We conclude that plasma membranes of latera l and dorsal rat prostate epithelial cells contain Ky K+ channels that hare biophysical and pharmacological properties consistent with those of the Kv 1.3 family. (C) 1999 Federation of European Bioehemical Societies.