Author(s)

Dina Kondratyeva, Sergey Afanasiev, Sergey Popov, Roman Batalov

Federal State Budgetary Institution Research Institute for Сardiology of Siberian Branch under the Russian Academy of Medical Sciences, Tomsk, Russia.
Federal State Budgetary Institution Research Institute for Сardiology of Siberian Branch under the Russian Academy of Medical Sciences, Tomsk, Russia..

The influence of amiodarone on intracellular transport of calcium ion in cardiomyocytes of rat was investigated. The experiments were performed on isolated papillary muscles of Wistar rats. Force-frequency dependence (0.7, 1, 2, 3, 4 Hz), extrasystolic and postextrasystolic contractions and post-rest (4-60 s) reactions of rat myocardium after amiodarone treatment (1 μM) were investigated. Decay potentiation coefficient of contraction force was estimated. Results. The analyses of force-frequency dependence has shown that amiodarone prevent the decreasing of the force contraction at increasing of the stimulation frequency. Amiodarone promotes increase of the time constant t₁(T₅₀), that indicate the drug promotes acceleration of Са²⁺ transport inside the SR resulting increase of Са²⁺ in the places of its release from the sarcoplasmic reticulum (SR). Treatment of papillary muscle with amiodarone decreased amplitude of extrasystolic contractions. As known, postextrasystolic and post-rest reactions of myocardium characterize the SR function. We have found amiodarone increased potentiation of postextrasystolic and post-rest contractions. Preliminary caffeine perfusion of muscles preparations cancelled the amiodarone-induced increasing postextrasystolic and post-rest potentiation. However, potentiation decay coefficient before and after treatment with amiodarone didn’t have difference. Conclusions, amiodarone influences on intracellular calcium ions homeostasis by modulation SR functions related with most likely are stipulated either by activation of Са²⁺ transport from uptake sites to release sites or by prevent of Са²⁺ leakage from the SR.

Amiodarone; Sarcoplasmic Reticulum Function; Postextrasystolic and Post-Rest Contractions; Papillary Muscles of Rat

D. Kondratyeva, S. Afanasiev, S. Popov and R. Batalov, "Amiodarone Modulation of Intracellular Transport of Calcium Ions in Cardiomyocites," Pharmacology & Pharmacy, Vol. 3 No. 3, 2012, pp. 307-315. doi: 10.4236/pp.2012.33041.