The effects of MCC-134 on the ATP-sensitive K+ channels in pig urethra
Takakazu Yunoki1, Noriyoshi Teramoto, Naruaki Takano
1Faculty of Medicine, Department of Pharmacology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi Ward, Fukuoka 812-8582, Japan.
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.
More Related Videos
10:26Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology
Published on: August 18, 2014
12:48Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays
Published on: February 19, 2013
Related Concept Videos
G-Protein Gated Ion Channels
Sensory organs,...
ATP Driven Pumps III: V-type Pumps
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
ATP Driven Pumps II: P-type Pumps
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
ATP Driven Pumps I: An Overview
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
