Repetitive stimulation increases the activation rate of skeletal muscle Ca2+ currents.
Voltage clamp experiments were conducted in frog skeletal muscle using repetitive stimulation protocols. The activation rate of Ca2+ currents increased by prepulses to depolarizing potentials or by stimulating the fiber with a frequency of 1.7 Hz at 0 mV. The effect was observable with Ca2+ or Ba2+ ions, and was clearly voltage-dependent. Physiologically, it is relevant that such activation rate increase can take place during a train of action potentials.
Garcia
J
J
Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030.
Avila-Sakar
A J
AJ
Stefani
E
E
D000200:Action Potentials; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D004553:Electric Conductivity; D004558:Electric Stimulation; D009132:Muscles / Q000378:metabolism*; D011894:Rana pipiens
D015220:Calcium Channels; D002118:Calcium