Ca ²⁺ spark-dependent and -independent sarcoplasmic reticulum Ca ²⁺ leak in normal and failing rabbit ventricular myocytes
Key result
Ryanodine receptors are the main but not sole contributor to sarcoplasmic reticulum Ca2+ leak, which occurs via both spark-dependent and independent pathways and is enhanced in failing hearts.
Population
Permeabilized normal and failing rabbit ventricular myocytes
Comparison
SERCA inhibition with thapsigargin, RyR… vs Normal vs failing myocytes; varying levels of…
Design
Preclinical
Authors
Discussion
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Implication
Non-spark Ca²⁺ leak pathways merit mechanistic study in HF models; leaves open their clinical relevance for diastolic dysfunction.
Structured PICO
P
Population
Permeabilized ventricular myocytes from normal and failing rabbit hearts.
I
Intervention
SERCA inhibition with thapsigargin, RyR sensitization with caffeine, and complete RyR inhibition
C
Comparator
Normal vs failing myocytes; varying levels of intra-SR free Ca2+
O
Outcome
SR Ca2+ leak rate and Ca2+ spark propertiessurrogate
RyRs are the main but not sole contributor to SR Ca2+ leak, with RyR-mediated leak occurring both as Ca2+ sparks and independent of sparks, and this leak is enhanced in failing hearts.
Cite This Study
Zima et al. (2010) studied Normal and failing rabbit hearts. Thapsigargin, caffeine, and RyR inhibition was evaluated on Sarcoplasmic reticulum Ca2+ leak and spark properties. Ryanodine receptors are the main but not sole contributor to sarcoplasmic reticulum Ca2+ leak, which occurs via both spark-dependent and independent pathways and is enhanced in failing hearts.