Research PaperSalvia miltiorrhiza (Danshen) inhibits L-type calcium current and attenuates calcium transient and contractility in rat ventricular myocytes

Ethnopharmacological relevanceSalvia miltiorrhiza (SM, Danshen), a traditional Chinese herbal drug, has been widely used for hundreds of years to treat coronary artery disease.Materials and methodsWe studied the effects of SM on the L-type Ca2+ current (ICa-L) with whole-cell patch-clamp technique in rat ventricular myocytes, and its influence on Ca2+ transient and contractility using video-based edge detection and dual excitation fluorescence photomultiplier systems as well.ResultsExposure to SM solution caused a concentration- and voltage-dependent blockade of ICa-L, and the dose of SM solution (10 g/l) decreased the maximal inhibitory effect of 35.2±1.2%. However, SM solution did not significantly change the current-voltage relationship or reversal potential of ICa-L, nor did it altered the activation and inactivation gating properties of cardiac Ca2+ channels. Meanwhile, SM decreased the amplitude of myocyte shortening and the peak value of Ca2+ transient with a significant decrease in the time to 90% of the baseline (Tr), but the time to 10% of the peak (Tp) was not dramatically prolonged.ConclusionsThe results indicated that SM significantly inhibited L-type Ca2+ channels, decreased [Ca2+]i and contractility in adult rat cardiac myocytes. These findings may be relevant to the cardioprotective efficacy of SM.

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