Sulfonylureas blockade of neural and cardiac HERG channels.
The human ether-a-go-go-related gene (herg) encodes a K+ current (I(HERG)) which plays a fundamental role in heart excitability and in neurons by contributing to action potential repolarization and to spike-frequency adaptation, respectively. In this paper we show that I(HERG), recorded in neuroblastoma cells and guinea-pig ventricular myocytes, was reversibly inhibited by the K(ATP) channel blocker glibenclamide (IC50 = 74 microM). The voltage and use dependence of glibenclamide blockade were also evaluated. Another sulfonylurea, glimepiride, had less effective results in blocking I(HERG). The findings of this study are relevant to the interpretation of glibenclamide effects on cellular electrophysiology and suggest that oral antidiabetic therapy with sulfonylureas may contribute to iatrogenic QT prolongation and related arrhythmias.
Rosati
B
B
Dipartimento di Fisiologia e Biochimica Generali, Università degli Studi di Milano, Milan, Italy.
Rocchetti
M
M
Zaza
A
A
Wanke
E
E
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D027682:Cation Transport Proteins; D002839:Chromans / Q000494:pharmacology; D004268:DNA-Binding Proteins; D004305:Dose-Response Relationship, Drug; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; D005905:Glyburide / Q000494:pharmacology*; D006168:Guinea Pigs; D006801:Humans; D020128:Inhibitory Concentration 50; D051379:Mice; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D009447:Neuroblastoma; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D015737:Nisoldipine / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000378:metabolism; D024642:Potassium Channels, Voltage-Gated; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D013449:Sulfonamides / Q000494:pharmacology; D013453:Sulfonylurea Compounds / Q000494:pharmacology*; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG; D014407:Tumor Cells, Cultured
D027682:Cation Transport Proteins; D002839:Chromans; D004268:DNA-Binding Proteins; C072312:ERG protein, human; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C000606913:KCNH2 protein, human; C092509:KCNH6 protein, human; D010880:Piperidines; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D011725:Pyridines; D013449:Sulfonamides; D013453:Sulfonylurea Compounds; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG; C063968:E 4031; C103474:6-cyano-4-(N-ethylsulfonyl-N-methylamino)-3-hydroxy-2,2-dimethylchromane; D015737:Nisoldipine; C057619:glimepiride; D005905:Glyburide