Open AccessEffects of Amphetamine on Calcium and Potassium Currents in Rat Heart
Author(s) -
Óscar Casis,
Laura Espiña,
Mónica Gallego
Publication year - 2000
Publication title -
journal of cardiovascular pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.762
H-Index - 100
eISSN - 1533-4023
pISSN - 0160-2446
DOI - 10.1097/00005344-200009000-00016
Subject(s) - cardiac transient outward potassium current , amphetamine , repolarization , ventricle , chemistry , medicine , ventricular fibrillation , calcium , membrane potential , anesthesia , electrophysiology , patch clamp , endocrinology , biochemistry , dopamine
We used the patch-clamp technique to study the effects of amphetamine on the membrane currents responsible for rat cardiac action-potential duration. Amphetamine has no effect on the slow inward Ca2+ current (I(Ca)-L), the inwardly rectifying K+ current (I(K1) and the outward K+ delayed rectifier (I(K)) and sustained (I(SS)) currents. Amphetamine blocks the transient outward K+ current (I(to)) both in the open and in the rested state. The transient outward K+ current is largely responsible for action-potential repolarization and for the regional differences in action-potential duration in rat ventricle. Therefore, the reduction of the transient outward K+ current (I(to)) caused by amphetamine may facilitate the appearance of ventricular tachycardia and fibrillation, a reported cause of death in amphetamine users.