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Updated: Sep 28, 2026

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
Chronic administration of amiodarone does not affect Na+/Ca2+ exchange current in guinea pig cardiac ventricular
Yasuhide Watanabe1, Isao Matsuoka, Junko Kimura
1Department of Ecology and Clinical Therapeutics, School of Nursing, Fukushima Medical University, Japan. w-yasu@tm.hama-med.ac.jp
Abstract:
We investigated chronic effects of amiodarone on Na+/Ca2+ exchange current (INCX) and on the level of Na+/Ca2+ exchanger (NCX1) mRNA in guinea pig ventricular myocytes using the whole-cell clamp technique and RT-PCR analysis, respectively. Guinea pigs were intraperitoneally injected with 80 mg/kg per day of amiodarone or the vehicle (saline) for 1 or 4 weeks. Single ventricular cells were isolated from the hearts of both groups of animals. Action potential duration at 90% repolarization level was prolonged to 143% and 165% of the control values by treatment with amiodarone for 1 and 4 weeks, respectively. INCX density and the level of NCX1 mRNA were not significantly changed by chronic treatment with amiodarone. The level of thyroid hormone (T4) within the blood was not changed by the treatments. These results suggest that chronic treatment with amiodarone does not affect the Na+/Ca2+ exchanger, with respect to the level of its mRNA and current density in guinea pig ventricular myocytes.
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