Source:http://linkedlifedata.com/resource/umls/id/C0010977
NCI: The sodium salt form of dantrolene, a hydantoin derivative and direct-acting skeletal muscle relaxant. Dantrolene depresses excitation-contraction coupling in skeletal muscle by binding to the ryanodine receptor 1, and decreasing intracellular calcium concentration. Ryanodine receptors mediate the release of calcium from the sarcoplasmic reticulum, an essential step in muscle contraction.