The effect of ruthenium red on Ca2+ transport and respiration in rat liver mitochondria

The inhibition of calcium uptake and release by rat liver mitochondria by ruthenium red

“…The studies of Vasington et al [2] confirmed these observations and further demonstrated that high concentrations of Ruthenium Red inhibit respiration. Currently there seems to be general agreement regarding the inhibitory effect of Ruthenium Red on mitochondrial calcium uptake but some degree of disagreement over the effect(s) of Ruthenium Red on the efflux of calcium from mitochondria.…”

“…Bearing these observations in mind, the inhibitory effect of Ruthenium Red on the phosphate-mediated release of calcium might be interpreted as a prevention of either the release of 45Ca from the membrane and/or an inhibition of phosphate transport. However, Vasington et al [2] , monitoring large amplitude swelling of mitochondria in ammonium phosphate as an indicator of phosphate transport, demonstrated that Ruthenium Red addition did not cause impairment of phosphate transport. Hence, it is suggested that in the present experiment Ruthenium Red probably inhibited the release of 4sCa from the membrane rather than the transport of phosphate.…”

Role of Ca2+ in regulating the level of mitochondrial pyrophosphate

“…In the presence of ruthenium red (1 FM), a mitochondrial Ca2+ transport inhibitor [26,27], the Ca2+-dependent elevation of PPi and inhibition of butyrate oxidation was 43 and 41%) respectively, of that observed with Ca2+ alone (table 1). In another experiment (not shown) when ruthenium red was preincubated with the mitochondria before Ca*+ addition to block Ca2+ uptake maximally, the Ca2+-dependent effects were only 26% and 27%, respectively, of that with Ca*+ alone.…”

ΔpH Induced Calcium Fluxes in Rat Liver Mitochondria

“…As to rat liver mitochondria the view of an independent pathway for Ca2+ efflux has been proposed by several authors on the basis of different lines of evidence [8,10,13,14,17,30,33,35,371.…”