title: Calcium dependent K-channels in guinea pig and human urinary bladder.
abstract: This study provides evidence for the presence of large conductance Ca(2+)-dependent K-channels in guinea pig and human urinary bladder smooth muscle. A23187, a Ca(2+)-ionophore, increased charybdotoxin and iberiatoxin sensitive 42K efflux in human urinary bladder smooth muscle cells, suggesting that large conductance Ca(2+)-dependent K-channels are present in these cells. NS004, a large conductance Ca(2+)-dependent K-channel opener, relaxed guinea pig bladder strips precontracted with 15 mM KCl which is inhibited by iberiatoxin. In addition, NS004 also evoked an iberiatoxin sensitive increase in 86Rb/42K efflux in guinea pig and human urinary bladder smooth muscle cells, demonstrating that NS004 activates large conductance Ca(2+)-dependent K-channels to achieve its relaxation effect in the bladder.
authors.affiliation: Department of Pharmacology and Medicinal Chemistry, Zeneca Pharmaceuticals Group, Zeneca Inc., Wilmington, DE 19897, USA.
authors.forename: S
authors.initials: S
authors.lastname: Trivedi
authors.forename: L
authors.initials: L
authors.lastname: Potter-Lee
authors.forename: J H
authors.initials: JH
authors.lastname: Li
authors.forename: G D
authors.initials: GD
authors.lastname: Yasay
authors.forename: K
authors.initials: K
authors.lastname: Russell
authors.forename: C J
authors.initials: CJ
authors.lastname: Ohnmacht
authors.forename: J R
authors.initials: JR
authors.lastname: Empfield
authors.forename: D A
authors.initials: DA
authors.lastname: Trainor
authors.forename: S T
authors.initials: ST
authors.lastname: Kau
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D018999:Charybdotoxin; D002733:Chlorophenols / Q000494:pharmacology; D004553:Electric Conductivity; D006168:Guinea Pigs; D006801:Humans; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D010455:Peptides / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D011189:Potassium Chloride / Q000494:pharmacology; D012414:Rubidium Radioisotopes; D012604:Scorpion Venoms / Q000494:pharmacology; D001743:Urinary Bladder / Q000187:drug effects / Q000502:physiology*
chemical_list: D001562:Benzimidazoles; D002733:Chlorophenols; D010455:Peptides; D015221:Potassium Channels; D012414:Rubidium Radioisotopes; D012604:Scorpion Venoms; D018999:Charybdotoxin; D000001:Calcimycin; C083230:NS 004; D011189:Potassium Chloride; C064719:iberiotoxin; D002118:Calcium