title: Inhibitory effect of glybenclamide on mitochondrial chloride channels from rat heart.
abstract: Glybenclamide is used as a pharmacological tool in studies of mitochondrial functions supposing its main role to block ATP-dependent potassium (KATP) channel. The aim of this study was to test whether glybenclamide might interact with the mitochondrial chloride channels. Mitochondrial membranes, isolated from rat heart muscle, were incorporated into lipid bilayer membrane and single chloride channel currents were measured in 250/50 mM KCl cis/trans solutions. The observed chloride channels (N=11) with mean conductance 120±14 pS were sensitive to glybenclamide, which decreased the open probability (IC50=129 μM) and affected the channel gating kinetics (IC50=12 μM) by perturbing its open state. It did not influence the channel conductance or reversal potential. These results indicate that glybenclamide interacts with chloride channels what should be taken into consideration, when glybenclamide is used as a specific inhibitor of KATP channels.
authors.affiliation: Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia.
authors.forename: Viera
authors.initials: V
authors.lastname: Kominkova
authors.forename: Karol
authors.initials: K
authors.lastname: Ondrias
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Tomaskova
mesh_terms: D000818:Animals; D018118:Chloride Channels / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005905:Glyburide / Q000378:metabolism / Q000494:pharmacology*; D007004:Hypoglycemic Agents / Q000378:metabolism / Q000494:pharmacology; D015640:Ion Channel Gating / Q000187:drug effects* / Q000502:physiology; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D051336:Mitochondrial Membranes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D011188:Potassium / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018118:Chloride Channels; D007004:Hypoglycemic Agents; D008051:Lipid Bilayers; D011189:Potassium Chloride; D011188:Potassium; D005905:Glyburide