AIMS/HYPOTHESIS: Opening of ATP-sensitive potassium (K(ATP)) channels during myocardial ischaemia shortens action potential duration and is believed to be an adaptive, energy-sparing response. Thiazolidinedione drugs block K(ATP) channels in non-cardiac cells in vitro. This study determined whether thiazolidinedione drugs block cardiac K(ATP) channels in vivo. METHODS: Experiments in 68 anaesthetised pigs determined: (1) effects of inert vehicle, troglitazone (10 mg/kg i.v.) or rosiglitazone (0.1 or 1.0 mg/kg i.v.) on epicardial monophasic action potential (MAP) during 90 min low-flow ischaemia; (2) effects of troglitazone, rosiglitazone or pioglitazone (1 mg/kg i.v.) on response of MAP to intracoronary infusion of a K(ATP) channel opener, levcromakalim; and (3) effects of inert vehicle, rosiglitazone (1 mg/kg i.v.) or the sarcolemmal K(ATP) blocker HMR-1098 on time to onset of ventricular fibrillation following complete coronary occlusion. RESULTS: With vehicle, epicardial MAP shortened by 44+/-9 ms during ischaemia. This effect was attenuated to 12+/-8 ms with troglitazone and 6+/-6 ms with rosiglitazone (p<0.01 for both vs vehicle), suggesting K(ATP) blockade. Intracoronary levcromakalim shortened MAP by 38+/-10 ms, an effect attenuated to 12+/-8, 13+/-4 and 9+/-5 ms during co-treatment with troglitazone, rosiglitazone or pioglitazone (p<0.05 for each), confirming K(ATP) blockade. During coronary occlusion, median time to ventricular fibrillation was 29 min in pigs treated with vehicle and 6 min in pigs treated with rosiglitazone or HMR-1098 (p<0.05 for both vs vehicle), indicating that K(ATP) blockade promotes ischaemic ventricular fibrillation in this model. CONCLUSIONS/ INTERPRETATION: Thiazolidinedione drugs block cardiac K(ATP) channels at clinically relevant doses and promote onset of ventricular fibrillation during severe ischaemia.
AIMS/HYPOTHESIS: Opening of ATP-sensitive potassium (K(ATP)) channels during myocardial ischaemia shortens action potential duration and is believed to be an adaptive, energy-sparing response. Thiazolidinedione drugs block K(ATP) channels in non-cardiac cells in vitro. This study determined whether thiazolidinedione drugs block cardiac K(ATP) channels in vivo. METHODS: Experiments in 68 anaesthetised pigs determined: (1) effects of inert vehicle, troglitazone (10 mg/kg i.v.) or rosiglitazone (0.1 or 1.0 mg/kg i.v.) on epicardial monophasic action potential (MAP) during 90 min low-flow ischaemia; (2) effects of troglitazone, rosiglitazone or pioglitazone (1 mg/kg i.v.) on response of MAP to intracoronary infusion of a K(ATP) channel opener, levcromakalim; and (3) effects of inert vehicle, rosiglitazone (1 mg/kg i.v.) or the sarcolemmal K(ATP) blocker HMR-1098 on time to onset of ventricular fibrillation following complete coronary occlusion. RESULTS: With vehicle, epicardial MAP shortened by 44+/-9 ms during ischaemia. This effect was attenuated to 12+/-8 ms with troglitazone and 6+/-6 ms with rosiglitazone (p<0.01 for both vs vehicle), suggesting K(ATP) blockade. Intracoronary levcromakalim shortened MAP by 38+/-10 ms, an effect attenuated to 12+/-8, 13+/-4 and 9+/-5 ms during co-treatment with troglitazone, rosiglitazone or pioglitazone (p<0.05 for each), confirming K(ATP) blockade. During coronary occlusion, median time to ventricular fibrillation was 29 min in pigs treated with vehicle and 6 min in pigs treated with rosiglitazone or HMR-1098 (p<0.05 for both vs vehicle), indicating that K(ATP) blockade promotes ischaemic ventricular fibrillation in this model. CONCLUSIONS/ INTERPRETATION:Thiazolidinedione drugs block cardiac K(ATP) channels at clinically relevant doses and promote onset of ventricular fibrillation during severe ischaemia.
Authors: John A Dormandy; Bernard Charbonnel; David J A Eckland; Erland Erdmann; Massimo Massi-Benedetti; Ian K Moules; Allan M Skene; Meng H Tan; Pierre J Lefèbvre; Gordon D Murray; Eberhard Standl; Robert G Wilcox; Lars Wilhelmsen; John Betteridge; Kåre Birkeland; Alain Golay; Robert J Heine; László Korányi; Markku Laakso; Marián Mokán; Antanas Norkus; Valdis Pirags; Toomas Podar; André Scheen; Werner Scherbaum; Guntram Schernthaner; Ole Schmitz; Jan Skrha; Ulf Smith; Jan Taton Journal: Lancet Date: 2005-10-08 Impact factor: 79.321
Authors: XiaoYong Tong; Lisa M Porter; GongXin Liu; Piyali Dhar-Chowdhury; Shekhar Srivastava; David J Pountney; Hidetada Yoshida; Michael Artman; Glenn I Fishman; Cindy Yu; Ramesh Iyer; Gregory E Morley; David E Gutstein; William A Coetzee Journal: Am J Physiol Heart Circ Physiol Date: 2006-02-24 Impact factor: 4.733
Authors: Ya Xu; Michael Gen; Li Lu; Jennifer Fox; Sara O Weiss; R Dale Brown; Daniel Perlov; Hasan Ahmad; Peili Zhu; Clifford Greyson; Carlin S Long; Gregory G Schwartz Journal: Am J Physiol Heart Circ Physiol Date: 2004-11-04 Impact factor: 4.733
Authors: N Szentandrássy; G Harmati; L Bárándi; J Simkó; B Horváth; J Magyar; T Bányász; I Lorincz; A Szebeni; V Kecskeméti; P P Nánási Journal: Br J Pharmacol Date: 2011-06 Impact factor: 8.739
Authors: Li Lu; Shuyu Ye; Rebecca L Scalzo; Jane E B Reusch; Clifford R Greyson; Gregory G Schwartz Journal: Diabetologia Date: 2017-05-11 Impact factor: 10.122