Journal of Pharmacological Sciences (Jan 2004)

The R(−)-Enantiomer of Efonidipine Blocks T-type but Not L-type Calcium Current in Guinea Pig Ventricular Myocardium

  • Hikaru Tanaka,
  • Chisa Komikado,
  • Hideaki Shimada,
  • Kentaro Takeda,
  • Iyuki Namekata,
  • Toru Kawanishi,
  • Koki Shigenobu

Journal volume & issue
Vol. 96, no. 4
pp. 499 – 501

Abstract

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In guinea pig ventricular cardiomyocytes, the R(−)-enantiomer of efonidipine concentration-dependently blocked T-type Ca2+ current with 85% inhibition at 1 μM. In contrast, R(−)-efonidipine (1 μM) 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. Keywords:: R(−)-efonidipine, T-type Ca2+ channel, cardiomyocyte