title: Minimal latency of calcium release in frog twitch muscle fibres.
abstract: Intracellular release of calcium in frog skeletal muscle fibres was monitored by the use of arsenazo III, in response to voltage clamped depolarizing pulses. A latency of a few milliseconds was evident between the onset of depolarization and the first detectable rise in the arsenazo-calcium signal, and this decreased logarithmically as the depolarization was increased. The minimal latency with strong depolarization (to +20 to +100 mV) was about 2 ms at 5 degrees C. This delay appears to be sufficiently long to be compatible with a chemically mediated coupling mechanism between depolarization and calcium release from the sarcoplasmic reticulum.
mesh_terms: D000818:Animals; D001150:Arsenazo III; D002118:Calcium / Q000502:physiology*; D008564:Membrane Potentials; D009119:Muscle Contraction; D009132:Muscles / Q000502:physiology*; D011896:Rana temporaria; D012508:Sarcolemma / Q000502:physiology; D013997:Time Factors
chemical_list: D001150:Arsenazo III; D002118:Calcium