Module 2: Figure cADPR action in heart cells

Effect of cADPR on spark frequency in heart cells.

When permeabilized rat ventricular myocytes were treated with 5 μM cADPR, there was a gradual increase in spark frequency that recovered to the resting level when it was washed off (wo). There was no change in spark amplitude. This increase in spark frequency was shown to depend upon sensitization of the RYRs due to an increase in the luminal load of Ca2+ resulting from an increase in the activity of the sarco/endo-plasmic reticulum Ca2+-ATPase (SERCA) pump. Reproduced from Lukyanenko, V., Györke, I., Wiesner, T.F. and Györke, S. (2001) Potentiation of Ca2+ release by cADP-ribose in the heart is mediated by enhanced SR Ca2+ uptake into the sarcoplasmic reticulum. Circ. Res. 89:614–622, with permission from Lippincott Williams & Wilkins (http:://; see Lukyanenko et al. 2001.