Excitation-Contraction Coupling In Skeletal Muscle: Comparisons With Cardiac Muscle

SUMMARY 1. The present review describes the mechanisms involved in controlling Ca2+ release from the sarcoplasmic reticulum (SR) of skeletal muscle, which ultimately regulates contraction. 2. Comparisons are made between cardiac and skeletal muscle with respect to: (i) the role of the dihydropyridine receptors (DHPR) as Ca2+ channels and voltage‐sensors; (ii) the regulation of the ryanodine receptor (RyR)/Ca2+‐release channels in the SR; and (iii) the importance of Ca2+‐induced Ca2+ release. 3. It is shown that the key differences of the skeletal muscle Ca2+‐release channel (RyR1), namely the increase in its stimulation by ATP and its inhibition by Mg2+, are critical for its direct regulation by the associated DHPR and, consequently, for the fast, accurate control of skeletal muscle contraction.