Use of ruthenium red as an inhibitor of mitochondrial Ca2+ uptake in single rat cardiomyocytes

[摘要]

With the current resurgence of interest in the role of mitochondrial [Ca²⁺] in energy production and cellular Ca²⁺ signalling, ruthenium red (RR) is being increasingly used as an inhibitor of mitochondrial Ca²⁺ uptake. In the present study, the effects of RR on cell and mitochondrial [Ca²⁺], and on cell contractility were determined in isolated rat ventricular myocytes subjected to adrenergic and electrical stimulation. At low concentrations, 0–1 μM, RR inhibited mitochondrial Ca²⁺ uptake but this was a secondary effect due to a reduced total intracellular [Ca²⁺], a conclusion supported by the ability of RR to inhibit cell shortening. 5 μM RR completely inhibited cell contraction, whereas higher concentrations, 10–25 μM, induced spontaneous Ca²⁺ oscillations and contractile waves. These results indicate that great care must be taken when using RR in intact cells, and in interpreting any effects as resulting from a primary inhibition of mitochondrial Ca²⁺ uptake.

[学科分类] 生物化学/生物物理

[关键词] Indo-1;Mitochondrion;Calcium;Ruthenium red;RR;ruthenium red;[Ca2+]i;intracellular [Ca2+];[Ca2+]m;mitochondrial [Ca2+];[Ca2+]c;cytosolic [Ca2+]