Pediatric Cardiology and Cardiac Surgery
Vol.25 No.2 2009 (102-109)

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Susumu Minamisawa

Department of Life Science and Bio-medical Science, Waseda University, Tokyo, Japan


The sarcoplasmic reticulum (SR) is an organellae that has been developed for intracellular Ca2+ storage. Periodic changes in Ca2+ concentration in cardiomyocytes, which are essential for cardiac contraction and relaxation, are integrally regulated by proteins associated with the SR. The activity of the cardiac ryanodine receptor (RyR2) and the SR calcium ATPase 2a (SERCA2a) are known to be under fine-tuning by their intrinsic regulatory domains and associated SR proteins. A growing body of evidence, including studies using genetically engineered mouse models and human genetics, has shown that both Ca2+ release by RyR2 and Ca2+ reuptake by SERCA2a play a pivotal role in heart failure and lethal arrhythmias. The improvement of the SR function has ameliorated effects on cardiac pump function and it has potential therapeutic value for heart failure and arrhythmias.