Journal of Pharmacological Sciences (Jan 2004)

Effect of Cilnidipine on L- and T-type Calcium Currents in Guinea Pig Ventricle and Action Potential in Rabbit Sinoatrial Node

  • Kentaro Takeda,
  • Reiko Yamagishi,
  • Haruko Masumiya,
  • Hikaru Tanaka,
  • Koki Shigenobu

DOI
https://doi.org/10.1254/jphs.scj04001x
Journal volume & issue
Vol. 95, no. 3
pp. 398 – 401

Abstract

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Cilnidipine, a dihydropyridine Ca2+ channel antagonist, is known to have inhibitory effects on both L- and N-type Ca2+ currents. In the present study, we examined the effect of cilnidipine on myocardial L- and T-type Ca2+ currents and sinoatrial node action potential configuration. In voltage clamped guinea pig ventricular myocytes, cilnidipine concentration-dependently decreased L- and T-type Ca2+ currents. In rabbit sinoatrial node tissue, cilnidipine increased cycle length through reduction of phase 4 depolarization slope. In conclusion, cilnidipine has inhibitory effects on T-type Ca2+ current, which may contribute to its negative chronotropic potency. Keywords:: cilnidipine, T-type Ca2+ channel, cardiomyocyte