Dopamine receptor agonists differ in their actions on cardiac ion channels

• Published in: European journal of pharmacology 2003-12, Vol.482 (1), p.31-37
• Main Authors: Hurst, Raymond S., Higdon, Nicole R., Lawson, Judy A., Clark, Michael A., Rutherford-Root, Karen L., McDonald, William G., Haas, Joseph V., McGrath, James P., Meglasson, Martin D.
• Format: Article
• Language: English
• Subjects: Action potential duration; Action Potentials - drug effects; Action Potentials - physiology; Animals; Biological and medical sciences; Cation Transport Proteins - antagonists & inhibitors; Cation Transport Proteins - metabolism; CHO Cells; Cricetinae; Dogs; Dopamine Agonists - pharmacology; Dopamine receptor agonist; Dose-Response Relationship, Drug; Ether-A-Go-Go Potassium Channels; hERG channel; In Vitro Techniques; Male; Medical sciences; Parkinson's disease; Pharmacology. Drug treatments; Potassium Channel Blockers - pharmacology; Potassium Channels - metabolism; Potassium Channels, Voltage-Gated; Purkinje Fibers - drug effects; Purkinje Fibers - metabolism; Receptors, Dopamine - physiology
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/j.ejphar.2003.09.054

Four dopamine receptor agonists used for the treatment of Parkinson's disease (apomorphine, pergolide, ropinirole and sumanirole) were evaluated for the ability to block human ether-a-go-go related gene (hERG) K + channels and to modify the duration of canine Purkinje fiber action potentials. Apomorphine, pergolide and ropinirole blocked the hERG-mediated currents with IC 50 values of 2.4, 0.12 and 1.2 μM, respectively. When evaluated in an action potential duration assay, pergolide significantly shortened action potential duration at 90% repolarization (APD 90) whereas apomorphine and ropinirole significantly prolonged repolarization. Sumanirole only partially blocked hERG K + channels at the highest tested concentration (10 μM) and did not modify action potential duration over the tested concentration range (0.65–65 μM). Taken together, these data provide evidence that dopamine receptor agonists developed for the treatment of Parkinson's disease differentially influence hERG K + channel function and cardiac action potential duration.