The R(-)-enantiomer of efonidipine blocks T-type but not L-type calcium current in guinea pig ventricular myocardium.
In guinea pig ventricular cardiomyocytes, the R(-)-enantiomer of efonidipine concentration-dependently blocked T-type Ca2+ current with 85% inhibition at 1 microM. In contrast, R(-)-efonidipine (1 microM) had no effect on the L-type Ca2+ current and Ca2+ transient in cardiomyocytes and contractile force in papillary muscles. Thus, R(-)-efonidipine is a highly selective blocker of the T-type Ca2+ current in native myocardia.
Tanaka
Hikaru
H
Department of Pharmacology, Toho University School of Pharmaceutical Sciences, Chiba 274-8510, Japan. htanaka@phar.toho-u.ac.jp
Komikado
Chisa
C
Shimada
Hideaki
H
Takeda
Kentaro
K
Namekata
Iyuki
I
Kawanishi
Toru
T
Shigenobu
Koki
K
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D020746:Calcium Channels, L-Type / Q000187:drug effects*; D020747:Calcium Channels, T-Type / Q000187:drug effects*; D004095:Dihydropyridines / Q000494:pharmacology*; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006352:Heart Ventricles; D009596:Nitrophenols / Q000494:pharmacology*; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D013237:Stereoisomerism
D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D020747:Calcium Channels, T-Type; D004095:Dihydropyridines; D009596:Nitrophenols; D009943:Organophosphorus Compounds; C066425:efonidipine