2,3,4,5-Тетрагидро-7-метокси-4- (метил-d3) -

t is a labelled benzothiazepine derivative that binds the RyR1 channel and enhances the binding affinity of Calstabin-1. By preventing the depletion of Calstabin-1 from the RyR1 complex, S 107 slows muscle fatique and reduces muscle damage in exercised mice. In a murine model of Duchenne muscular dystrophy, S 107 reduces biochemical and histological evidence of the muscle damage associated with muscular dystrophy, improves muscle function, and increases exercise performance.