What impact does dantrolene have on muscle fibers?

Dantrolene is a muscle relaxant primarily used to treat conditions like malignant hyperthermia and certain muscle disorders. Its mechanism of action specifically involves the inhibition of calcium release from the sarcoplasmic reticulum in muscle fibers. By blocking the ryanodine receptors, which are critical for calcium release, dantrolene reduces the availability of calcium that is essential for muscle contraction.

This inhibition leads to decreased frequency and force of contractions, which is beneficial in conditions where excessive muscle contraction occurs. In essence, by impairing calcium release, dantrolene effectively reduces muscle rigidity and spasms, facilitating relaxation of the muscles. This is why the choice indicating that dantrolene inhibits calcium release is the correct understanding of its impact on muscle fibers.