Fetal and Neonatal Development of Ca2+ Transients and Functional Sarcoplasmic Reticulum in Beating Mouse Hearts

Abstract

Ca(2+) homeostasis developmentally changes from a slow rise and decay of Ca(2+) transients to rapid kinetics after the mid-embryonic stage. SERCA began to contribute significantly to Ca(2+) homeostasis at early embryonic stages and sarcoplasmic reticulum Ca(2+) contents increased from embryonic to neonatal stages, whereas mitochondrial Ca(2+) uptake did not contribute to Ca(2+) transients on a beat-to-beat basis.