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Updated: Jul 17, 2026

Synthesis and Evaluation of a Ruthenium-based Mitochondrial Calcium Uptake Inhibitor
Published on: October 26, 2017
Ruthenium red reduces acetylcholine sensitivity and increases desensitization at the frog neuromuscular junction
1Department of Physiology, College of Physicians and Surgeons, Columbia University, New York, NY 10032.
Abstract:
The actions of Ruthenium Red on the synaptic membrane were studied at the neuromuscular junction of the frog Rana pipiens. Ruthenium Red blocks mitochondrial calcium transport and thus is expected to elevate the intracellular calcium level [Alnaes and Rahamimoff (1975) J. Physiol., Lond. 248, 285-306]. The postjunctional membrane sensitivity was reduced by Ruthenium Red as determined by (a) the amplitude of the miniature endplate potentials, (b) iontophoretic application of carbachol, (c) microperfusion of carbachol. Desensitization was assayed by measuring the decline in the amplitude of the postsynaptic depolarization produced during repetitive iontophoretic application of carbachol. Following Ruthenium Red treatment desensitization was increased. This action of Ruthenium Red was enhanced by raising the extracellular calcium concentration from 1.8 to 10 mM.
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