title: K+ channel currents in rat ventral prostate epithelial cells.
abstract: BACKGROUND
  Electrophysiological function of the normal prostate has not been extensively studied. In particular, ion channel currents and their regulation have not been studied in freshly-isolated prostate cells.
  
  
  METHODS
  Rat prostate secretory epithelial (RPSE) cells were isolated by collagenase treatment. Columnar epithelial cells were used for nystatin-perforated, whole-cell voltage clamp, and the intracellular Ca(2+) concentration ([Ca(2+)](i)) was measured using fura-2.
  
  
  RESULTS
  Step-like depolarizing pulses (900 msec) starting from - 90 mV induced outwardly rectifying K(+) currents without inactivation. ACh (10 microM) or ATP (100 microM) increased the outward current and hyperpolarized the cell membrane potential. Ionomycin (0.1 microM), a Ca(2+) ionophore, induced a similar increase in the outward current. TEA (5 mM), charybdotoxin (50 nM), and iberiotoxin (30 nM) inhibited the effect of ACh (or ATP) on the outward current, whereas apamin (100 nM) had no effect. The [Ca(2+)](i) of RPSE cells was increased by ACh, ATP, and UTP.
  
  
  CONCLUSIONS
  RPSE cells have iberiotoxin-sensitive Ca(2+)-activated K(+) channels that may play an important role in the exocrine secretions of the prostate.
authors.affiliation: Department of Physiology, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea.
authors.forename: Jun Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Eun-Kyung
authors.initials: EK
authors.lastname: Hong
authors.forename: Hee Sook
authors.initials: HS
authors.lastname: Choi
authors.forename: Seung-Joon
authors.initials: SJ
authors.lastname: Oh
authors.forename: Kwang Myung
authors.initials: KM
authors.lastname: Kim
authors.forename: Dae-Yong
authors.initials: DY
authors.lastname: Uhm
authors.forename: Sung Joon
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology; D004553:Electric Conductivity; D004847:Epithelial Cells / Q000502:physiology; D007425:Intracellular Membranes / Q000378:metabolism; D008297:Male; D009994:Osmolar Concentration; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000819:agonists / Q000187:drug effects / Q000502:physiology*; D011467:Prostate / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015221:Potassium Channels; D000255:Adenosine Triphosphate; D000109:Acetylcholine; D002118:Calcium