Ruthenium red staining of intracellular organelles and structures seemed to depend on the time of exposure to this agent, as well on the concentration used.

Ruthenium red efficiently blocks the L-type calcium current in a dose-dependent manner in in guinea-pig isolated ventricular heart cells, with EC

50

of 0.8 μM.

Ruthenium red (10 μM) blocks the sarcoplasmic Ca release channels or the mitochondrial Ca uptake, and blocks 26.7 % of the sodium current, and slowed its inactivation time-course in guinea-pig isolated ventricular heart cells.