Millimolar caffeine activated canine cardiac sarcoplasmic reticulum Ca2+-release channels by increasing the frequency and duration of open events.
Caffeine is thought to affect excitation-contraction coupling in cardiac muscle by activating the sarcoplasmic reticulum (SR) Ca2+-release channel. The effect of caffeine at the single channel level was studied by incorporating canine cardiac SR vesicles into planar lipid bilayers. Cardiac Ca2+-release channels were activated in a steady-state manner by millimolar cis-caffeine and displayed a unitary conductance (77 pS in 50 mM Ca2+ trans) similar to that previously observed for the Ca2+-activated cardiac channel. The caffeine-activated channel was moderately sensitive to the voltage applied across the bilayer, was sensitive to further activation by ATP, and was inhibited by Mg2+ and ruthenium red. Kinetic analysis showed that at low Ca2+ concentration, caffeine activated the channel by increasing the frequency and the duration of open events.
Building similarity graph...
Analyzing shared references across papers
Loading...
AJP Heart and Circulatory Physiology
University of North Carolina at Chapel Hill
Add This Paper to Your Research Feed
Any time a new paper drops it will be there.
Rousseau et al. (Wed,) conducted a other in Cardiac muscle excitation-contraction coupling. Caffeine was evaluated on Activation of cardiac Ca2+-release channels. Millimolar caffeine activated canine cardiac sarcoplasmic reticulum Ca2+-release channels by increasing the frequency and duration of open events.