title: The effects of MCC-134 on the ATP-sensitive K+ channels in pig urethra.
abstract: We have investigated the effects of MCC-134 (1-[4-(1H-imidazol-1-yl)benzoyl]-N-methyl-cyclobutanecarbothioamide) on membrane currents and ATP-sensitive K(+) channel (K(ATP) channel) opener-induced currents in pig urethra by use of patch-clamp techniques (conventional whole-cell configuration and nystatin perforated patch recordings). Tension measurement was also performed to study the effects of MCC-134 on the resting tone of pig urethral strips. MCC-134 reduced the resting tone of pig urethra in a concentration-dependent manner (EC(50)=6 microM). The MCC-134 (30 microM)-induced relaxation was suppressed by glibenclamide. In voltage-clamp experiments, MCC-134 produced a concentration-dependent inward K(+) current which was suppressed by application of glibenclamide at a holding potential of -50 mV (symmetrical 140 mM K(+) conditions). Application of MCC-134 enhanced diazoxide-induced inward currents and inhibited pinacidil-induced inward currents in a concentration-dependent manner at -50 mV. These results suggest that MCC-134 induces glibenclamide-sensitive K(ATP) currents in pig urethra.
authors.affiliation: Faculty of Medicine, Department of Pharmacology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi Ward, Fukuoka 812-8582, Japan.
authors.forename: Takakazu
authors.initials: T
authors.lastname: Yunoki
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Teramoto
authors.forename: Naruaki
authors.initials: N
authors.lastname: Takano
authors.forename: Narihito
authors.initials: N
authors.lastname: Seki
authors.forename: Kate E
authors.initials: KE
authors.lastname: Creed
authors.forename: Seiji
authors.initials: S
authors.lastname: Naito
authors.forename: Yushi
authors.initials: Y
authors.lastname: Ito
mesh_terms: D000255:Adenosine Triphosphate / Q000502:physiology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D007093:Imidazoles / Q000494:pharmacology*; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D015221:Potassium Channels / Q000819:agonists / Q000502:physiology*; D013552:Swine; D013854:Thioamides / Q000494:pharmacology*; D014521:Urethra / Q000187:drug effects* / Q000502:physiology
chemical_list: D007093:Imidazoles; C403079:MCC 134; D015221:Potassium Channels; D013854:Thioamides; D000255:Adenosine Triphosphate