Aim: To investigate the effects of N6-cyclopentyladenosine (CPA, selective adenosine A1 receptor agonist) on afterdepolarizations and triggered activity induced by isoproterenol (Iso) in guinea pig papillary muscle. Methods: The stable and reproducible early afterdepolarization (EAD) and delayed afterdepolarization (DAD) of guinea pig papillary muscle were induced by Iso 50 nmol · L-1. The parameters of EAD and DAD were recorded using intracellular microelectrodes. Results: CPA markedly attenuated the development of EAD, DAD, and triggered activity (TA) induced by Iso in guinea pig papillary muscle. The inhibitory effects of CPA on Iso-induced EAD and DAD were antagonized by 8-phenyltheophylline (8-PT) and glibenclamide (Gli). Conclusion: ATP-sensitive K+ channels were involved in Iso-induced EAD and DAD, and in the inhibitory effects of CPA on EAD and DAD.
|Original language||English (US)|
|Number of pages||6|
|Journal||Acta Pharmacologica Sinica|
|State||Published - 1995|
- papillary muscles
ASJC Scopus subject areas
- Pharmacology (medical)