On the Molecular Mechanism of Excitation–Transcription Coupling in Skeletal Muscle: Calcium Signaling and Excitation–Contraction in Cardiac, Skeletal and Smooth Muscle

ATP release occurs in two peaks, the first around 15 s after electrical stimulation (ES) and a second around 300 s after ES. Researchers used apyrase to hydrolyze ATP 60 s after ES, maintaining the first peak and eliminating the second peak.